Indian Patents. 239496:A PROCESS OF PREPARING CRYSTALLINE DULOXETINE FREE BASE

Title of Invention	A PROCESS OF PREPARING CRYSTALLINE DULOXETINE FREE BASE
Abstract	The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10, rule 13) “CRYSTALLINE FORMS OF DULOXETINE FREE BASE" CIPLA LIMITED 289 Bellasis Road, Mumbai Central, Mumbai 400 008, India The following specification particularly describes the invention and the manner in which it is to be performed. 2 PHARMACEUTICAL COMPOUND AND POLYMORPHS THEREOF The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof. Duloxetine, N-methyl-3-(l-naphthalenyloxy)-3-(2-thienyl)propanamine, is a dual serotonin and norepinephrine reuptake inhibitor. (H-)Duloxetine has particular therapeutic utility as an anti-depressant. Duloxetine, and the preparation thereof, is described1 in US patents 5023269 and 4956388, and also Tetrahedron Letters, 31, (49), 7101-04, 1990. Seven different routes of synthesis have also been reported in Drugs of the Future 2000, 25(9) 907-916. These syntheses have involved either a resolution of a key intermediate or a stereospecific reduction of a keto group to the alcohol. Isolation of duloxetine free base in crystalline form has not, however, been achieved by any of the processes described in the reported literature and patents. There is now provided by the present invention, however, duloxetine free base in crystalline form. The present invention further provides processes of preparing three different polymorphic forms of duloxetine, herein designated Forms A, B and C respectively, and i these three polymorphic forms represent further embodiments jof the present invention. As used herein, the term "duloxetine" preferably designates (+) duloxetine. According to the present invention, there is provided crystalline duloxetine free base, Form A, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 1. More particularly, crystalline duloxetine free base Form A i according to the present invention can be characterised as having an X-ray diffraction pattern with characteristic peaks (20): 9.70, 10.88, 13.03, 15.61, 19.19, 19.55, 19.88, 21.94, 22.16, 26.95 and 27.76°. Further characterising data for crystalline duloxetine free base Form A according to the present invention as obtained by X-ray diffraction is shown in following table 1. Table 1 Peak No. 29 (deg) FWHM (deg) d (A) Intensity (Counts) I/lo 1 9.700 0.212 9.1103 1107 27 2 10.880 0.188 8.1248 1372i 34' 3 12.050 0.165 7.3384 643 16 4 12.290 0.188 7.1956 721i 18 5 13.030 0.294 6.7886 154\|8 38 6 13.910 0.129 6.3610 431 11 7 15.610 0.235 5.6719 243!2 59 8 17.300 0.188 5.1214 6521 16 9 17.770 0.318 4.9870 443 11 10 18.410 0.118 4.8151 599 15 11 19.030 0.153 4.6596 2632 64 12 19.190 0.235 4.6211 309,8 75 13 19.550 0.176 4.5368 2429 59 14 19.880 0.235 4.4622 4143 100 15 20.170 0.165 4.3987 1332 33 16 20.910 0.271 4.2447 1119 27 17 21.200 0.200 4.1873 11271 28 18 21.940 0.271 4.0477 3684i 89 19 22.160 0.200 4.0080' 3494 85 20 22.730 0.106 3.9088 584 15 21 23.290 0.165 3.8160 71j3 18 22 . 23.420 0.129 3.7951 673 17 23 23.660 0.165 3,7572 7l'8 18 24 24.350 0.235 3.6523 2351/ i 57 25 24.810 0.224 3.5856 969 24 26 25.280 0.129 3.5200 9501 23 27 25.460 0.188 3.4955 1042 .26 28 26.070 0.106 3.4151 53(3. 1 13 29 26.950 0.247 3.3055 1527 1 37 30 27.360 0.188 3.2569 1078 27 31 27.760 0.247 3.2109 1653 40 32 28.700 0.118 3.1078 6^8 16 33 29.460 0.318 3.0293 916i 23 34 29.930 0.365 2.9828 1118 27 35 30.970 0.106 2.8850 7631 19 36 31.130 0.188 2.8705 769 19 37 31.590 0.294 2.8298 1038 26 38 33.170 0.129 2.6985 5V 14 39 33.520 0.106 2.6711 646i 16 40 33.700 0.176 2.6573 668I 17 41 33.940 0.118 2.6390 626.i 16 42 34.860 0.306 2.5715 685 17 43 36.370 0.118 2.4681 816 20 44 36.740 0.271 2.4441 1052 26 45 37.150 0.118 2.4180 954 24 46 37.330 0.118 2.4068 9531 23 47 39.710 0.165 2.2679 806 20 48 40.090 0.176 2.2472 7381 18 49 40.700 0.118 2.2149 658 16 50 41.050 0.153 2.1969 766 19 51 41.610 0.106 2.1686 883 22 24 52 41.690 0.141 2.1646 962 53 42.290 0.118 2.1353 770 19 54 42.420 0.129 2.1290 818i 20 55 42.720 0.165 2.1148 692 17 According to the present invention, there is provided crystalline duloxetine free base, Form B, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 2. More particularly, crystalline duloxetine free base Form B according to the present invention can be characterised as having an X-ray diffraction pattern with characteristic peaks (29): 4.98, 9.96, 11.18, 12.58, 15.32, 18.98, 20.04, 20.62, 22.32, 22.44, 27.28 and 30.30°. Further characterising data for crystalline duloxetine free base Form B according to the present invention as obtained by X-ray diffraction is shown1 in following table 2. Table 2 Peak No. 29 (deg) FWHM (deg) d (A) Intensity (Counts) I/Io 1 4.980 0.188 17.7294 915 17 2 9.960 0.212 8.8731 1269 23 3 11.180 0.235 7.9074 2278 41 4 11.580 0.212 7.6352 749 14 5 12.580 0.259 7.0304 1131i 21 6 14.580 0.259 6.0702 576 11 7 15.320 0.282 5.7786 1767 32 8 17.860 0.118 4.9621 640i 12 9 17.980 0.141 4.9293 6^0 13 10 18.980 0.353 4.6717 3036 55 11 20.040 0.235 4.4270 5583 100 12 20.620 0.282 4.3037 17il6 31 13 21.000 0.306 4.2267 1383 25 14 22.320 0.306 3.9796 4190 76 15 22.440 0.141 3.9586 3576 65 16 23.220 0.141 3.8274 1435i 26 17 23.340 0.188 3.8080 1498 27 18 23.840 0.259 3.7292 1382 25 19 24.560 0.118 3.6215 726 13 20 25.000 0.165 3.5588 1010 19 21 25.160 '•'■ 0.400 3.5365 1089 20 22 27.280 0.400 3.2663 2364 43 23 27.760 0.306 3.2109 19961996 36 24 30.300 0.329 2.9473 2574 47 25 30.880 0.118 2.8932 944j 17 26 31.140 0.118 2.8696 921]i 17 27 31.840 0.141 2.8081 985] 18 28 32.000 0.165 2.7945 1003 18 29 32.180 0.118 2.7792 822\| 15 30 36.760 0.212 2.4428 871 16 31 37.120 0.118 2.4199 1095 20 32 37.420 0.306 2.4012 1360 25 33 38.380 0.141 2.3433 860i 16 34 38.560 0.259 2.3328 890 16 According to the present invention, there is provided crystalline duloxetine free base, Form C, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 3. More particularly, crystalline duloxetine free base Form C according to the present invention can be characterised as having an X-ray diffraction pattern with characteristic peaks (20): 12.23, 13.49, 16.90, 18.28, 20.37, 22.61, 27.22, 27.40 and 30.65°. Further characterising data for crystalline duloxetine free base Form C according to the present invention as obtained by X-ray diffraction is shown in following table 3. Table 3 Peak No. 20 (deg) FWHM (deg) d (A) Intensity (Counts) l/Io 1 11.160 0.306 7.9215 \9\\ 51 2 12.230 0.318 7.2308 919! 25 3 ' 12.570 0.224 7.0360 872 23 4 13.490 : 0.400 6.5581 1419 38 5 15.050 0.341 5.8817 6J10 17 6 16.900 0.282 5.2417 850i 23 7 18.280 0.400 4.8490 1717 46 8 18.840 0.388 4.7061 16461 44 9 19.500 0.106 4.5483 941 25 10 19.660 0.129 4.5117 1141i 30 11 20.370 0.424 4.3560 3573 94 12 20.810 0.271 4.2649 1890i 50 13 21.710 0.106 4.0900 6;37 17 14 22.610 0.424 3.9292 38081 100 15 23.080 0.212 3.8503 1206 32 16 23.850 0.247 3.7277 ■7j25 20 17 25.140 0.318 3.5393 958 26 18 25.570 0.318 3.4807 1065 28 19 27.220 0.141 3.2733 1534 41 . 20 27.400 0.400 3.2522 1778 47 21 27.830 0.129 3.2030 7^6 21 22 28.030 0.129 3.1806 704 19 23 28.440 0.224 3.1356 696 19 24 29.730 0.153 3.0024 696i 19 25 30.180 0.129 2.9587 989I 26 26 30.650 0.471 2.9144 1636I 43 27 32.340 0.129 2.7658 746i 20 28 32.530 0.224 2:7501 836 22 29 34.420 0.200 2.6033 708i 19 30 34.900 0.118 2.5686 760 20 31 35.080 0.188 2.5558 787i 21 32 36.730 0.235 2.4447 8151 22 33 - 36.990 0.106 2.4281 785 21 34 37.230 0.271 2.4130 812 22 35 40.430 0.106 2.2291 796 21 36 40.600 0.176 2.2202 8J13 22 ._ 37 42.970 0.306 2.1030 1057 There is also provided by the present invention a pharmaceutical^ acceptable salt of dluloxetine, which pharmaceutical^ acceptable salt is prepared from duloxetine free base in crystalline form as provided by the present invention. Preferred pharmaceutical^ acceptable salts of duloxetine as provided by the present invention include \|duloxetine hydrochloride and dluloxetine oxalate, especially duloxetine hydrochloride. A pharmaceutical^ acceptable salt of duloxetine as provided by the present invention is preferably at least about 99.5% w/w pure. Crystalline duloxetine free base as provided by the present invention can in turn be prepared from salts of duloxetine, such as the oxalate salt, hydrochloride salt, di-p-toluyl tartrate salt, or any other suitable salt. According to the present invention, there is further provided a process of preparing crystalline duloxetine free base, which process comprises dissolving or suspending a salt of duloxetine in a suitable medium, such as water, neutralizing with a suitable base, such as an alkali metal hydroxide, (typically sodium hydroxide, extracting the thus formed duloxetine free base into a suitable Isolvent, replacing the solvent with a non-solvent, and thus isolating duloxetine free base in crystalline form. It is also possible to interconvert distinct polymorphic forms of crystalline duloxetine ■ free base as provided by the present invention. There is, therefore, further provided by the present invention an interconversion process, whereby a second polymorphic form of crystalline duloxetine free base is prepared from a distinct first polymorphic form of crystalline duloxetine free base. Suitably, the first polymorphic form of crystalline duloxetine free base which is employed as the starting material! is dissolved or suspended in a suitable lower alcohol solvent, preferably methanol, and the second polymorphic form is re-crystallized therefrom. Preferably, this interconversion process is employed for the preparation of crystalline duloxetine free base Form B from Form A substantially as hereinafter described in further detail. 9 The preparation of crystalline duloxetine free base according to the present invention is advantageous in that crystalline duloxetine free base can be employed as a useful intermediate in the preparation of highly pure pharmaceutically acceptable salts of duloxetine, in particular duloxetine oxalate or hydrochloride. Pharmaceutically acceptable salts of duloxetine prepared from crystalline duloxetine free! base can exhibit beneficial properties, for example, duloxetine hydrochloride prepared from crystalline duloxetine free base as provided by the present invention is more resistant to! degradation than duloxetine hydrochloride prepared by conventional methods known from the prior art. According to the present invention there is further provided a process of preparing crystalline duloxetine free base Form A, which process comprises suspending or dissolving a duloxetine salt, such as the hydrochloride or di-p-toluyl tartarate salt of duloxetine, in water, neutralizing with a base, such as an alkali metal hydroxide, typically sodium hydroxide, extracting into a substantially water immiscible solvent,! such as dichloromethane, I concentrating the substantially water immiscible solvent, replacing the substantially water immiscible solvent with acetone and thus isolating duloxetine free base Form A in crystalline form. Crystalline duloxetine free base Form A is characterized by powder x-ray diffraction substantially as shown in Figure 1. According to the present invention there is further provided a process of preparing crystalline duloxetine free base Form B, which process comprises dissolving or suspending a first polymorphic form of crystalline duloxetine free base, typically duloxetine free base Form A, in a suitable lower alcohol solvent, preferably methanol, and recrystallizing i duloxetine free base Form B therefrom. Crystalline duloxetine free base Form B is characterized by powder x-ray diffraction substantially as shown in Figure 2. According to the present invention there is further prqvided a process of preparing crystalline duloxetine free base Form C, which process comprises suspending or dissolving a duloxetine salt, such as the hydrochloride or di-p-toluyl tartarate salt of duloxetine, in water, neutralizing with a base, such as an alkali metal hydroxide,] typically sodium hydroxide, extracting into a substantially water immiscible solvent, such as dichloromethane, concentrating the substantially water immiscible solvent, replacing the substantially water immiscible solvent with isopropanol and thus isolating duloxetine free base Form C in crystalline form. Crystalline duloxetine free base Form C is characterized by powder x-ray diffraction substantially as shown in Figure 3. 10 There is also provided by the present invention , a process of preparing a pharmaceutical^ acceptable salt of duloxetine, which process comprises dissolving or suspending crystalline duloxetine free base as provided by the; present invention in a water miscible solvent, such as acetone, adding a pharmaceutically acceptable acid thereto required to form the pharmaceutically acceptable salt, and isolating the required pharmaceutically acceptable salt of duloxetine in crystalline form. Any of polymorphic forms A, B or C of crystalline duloxetine free base as provided by the present invention can be employed as crystalline duloxetine free base starting material for the above process of preparing a pharmaceutically acceptable salt of duloxetine. Suitable acid addition salts which can be prepared from crystalline duloxetine free base according to the present invention include those formed with pharmaceutically acceptable organic or inorganic acids and are well known to those of skill in the art. Acids commonly employed to form such salts include inorganic acids such as hydrochloric, hydrobromic, hydroiodic, sulfuric and phosphoric acid, as well as organic acids such as para-toluenesulfonic, methanesulfonic, oxalic, para-bromophenylsulfonic, carbonic, succinic, citric, benzoic and acetic acid, and related inorganic! and organic acids. Such pharmaceutically acceptable salts thus include sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, isobutyrate, caprate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, butyne-l,4-dioate, hexyne-l,6-dioate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, terephathalate, sulfonate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, 3-hydroxybutyrate, glycollate, maleate, tartrate, methanesulfonate, propanesulfonates, naphthalene-1-sulfonate, naphthalene-2-sulfonate, mandelate and the like salts. Preferred pharmaceutically acceptable acid addition salts include those formed with mineral acids such as hydrochloric acid and hydrobromic acid, and those formed with organic acids such as oxalic acid and maleic acid. A particularly preferred acid addition salt is the hydrochloride. As noted above, duloxetine is a dual serotonin and norepinephrine reuptake inhibitor. i The present invention further provides a pharmaceutically acceptable formulation for administering to a patient, including humans, suffering from, or susceptible to, a disease state 11 prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor, which formulation comprises a therapeutically effective amount of crystalline duloxetine free base, optionally as any of Forms A, B or G, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, together with a pharmaceutically acceptable carrier, diluent or excipient therefor. As used herein, the term "therapeutically effective amount" means an amount of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as i hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, which is capable of preventing, ameliorating or eliminating a disease state for which administration of a serotonin and / or norepinephrine reuptake inhibitor is indicated. By "pharmaceutically acceptable formulation" it is meant that the carrier, diluent or excipient is compatible with crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, and not deleterious to a recipient thereof. Pharmaceutical formulations as provided by the present invention can be prepared by known procedures using well known and readily available ingredients. In preparation of formulations as provided by the present invention, crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, can be mixed with a carrier, diluent or excipient therefor. Formulations as provided by the present invention can be I in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, jemulsions, solutions, syrups, i aerosol, ointments containing, for example, up to 10% by weight of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, soft and hard gelatin icapsules, suppositories, sterile injectable solutions and sterile packaged powders. In particular, capsules are suitable formulations for use in accordance with the present invention, which can typically include 12- coated non pareil seeds substantially as hereinafter illustrated in further detail by reference to the Examples. Some examples of suitable carriers, excipients. and diluents include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyviny syrup, methyl cellulose, methyl- and propylhydroxybenzoates, mineral oil. The formulations can additionally include lubricating agents, wetting agents, emulsifying and suspending agents, preserving agents, sweetening agents or flavoring agents. The formulations of the invention may be formulated so as to provide quick, sustained or delayed release of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, after administration to the patient by employing procedures well known in the art. The formulations are preferably formulated in a unit dosage form, each dosage containing1 from about 5 to about 500 mg, more usually about 25 to about 300 mg, of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described,. The term "unit dosage form" refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical carrier. There is also provided by the present invention crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, for use in therapy. The present invention further provides crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, for use in the manufacture of a medicament for the treatment of a . ■ I disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor as described herein. 13 The present invention also provides a method of treating a disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor in a patient in need of such treatment, which method comprises administering to the patient a therapeutically effective amount of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described. A variety of physiologic functions have been shown I to be subject to influence by brain serotoninengic and norepinephrinergic neural systems. As such, crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, of the present invention, or a pharmaceutically acceptable salt of] duloxetine as provided by the present invention substantially as hereinbefore described, has utility in the treatment of a variety of disorders in mammals associated with these initial systems such as obesity, depression, alcoholism, pain, loss of memory, anxiety and smoking. In particular, crystalline duloxetine free base, optionally as any of Forms A, B or C[ substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, has utility in the treatment of depression. In a preferred aspect of the present invention, therefore, there is provided crystalline duloxetine free base, optionally as any of Forms A, B or CJ, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, for use in the manufacture of a medicament for the treatment of depression. In a preferred aspect of the present invention, therefore, there is also provided a method of treating depression in a patient in need of such treatment, which method comprises j administering to the patient a therapeutically effective amount of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described. The particular dose of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, administered according to this invention will of course be determined by the particular 14 circumstances surrounding the case, the route of administration, the particular condition being treated, and similar considerations. Crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, can be administered by a variety of routes including the oral, rectal, transdermal, subcutaneous, intravenous, intramuscular or intranasal routes. A typical daily dose will contain from about 0.01 mg/kg to about 20 mg/kg of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, of the present invention, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described,. Preferred dai y doses will be about 0.05 to about 10 mg/kg, ideally about 0.1 to about 5 mg/kg. The present invention will now be further illustrated by the Figures and following Examples, which do not limit the scope of the invention in any way. Figure 1 is a powder X-ray diffraction pattern for crystalline duloxetine free base Form A. Figure 2 is a powder X-ray diffraction pattern for crystalline duloxetine free base Form B. Figure 3 is a powder X-ray diffraction pattern for crystalline duloxetine free base Form C. The above referred to X-ray diffraction patterns were obtained on a Rigaku Miniflex X-ray Diffractometer equipped with a Cu Ka source and a scintillation counter detector. The scan speed was 2 degrees per minute and the range was from 3 to 45 degrees. Examples Reference Example - Preparation of duloxetine (-~)di-p-toluyl tai tarate 1. Racemic Duloxetine (100gm) was added to methanol (200ml). 2. (-) Di-p-Toluoyl-L-Tartaric acid (130gm) was added lotwise at 25-30°C. 3. The contents were heated to 60-65°C and maintained for 1 hour at 60-65°C. 4. Methanol was completely distilled under vacuum at 45-50°C. 5. Acetone (1.5lit) was added to the residue and stirred for 3 hours at 25-30°C. 6. The solids were filtered, washed with acetone (100ml) and dried under vacuum at 45-50°C to give the title compound (80gm). Example 1 Preparation of duloxetine free base (Form A) 1. To Duloxetine (-) Di-p-toluyl tartarate (100gm), prepared by the above Reference i Example, was charged water (Hit), followed by stirring at 25-30°C for 15 minutes. 2. Slowly, lye solution (8gm sodium hydroxide in 50ml water) was added and stirred for 10-15 minutes at 25-30°C. 3. The mixture was extracted twice with methylene chloride (500ml). 4. Combined methylene chloride layers were washed with water (100ml). 5. Methylene chloride was distilled out under vacuum at a temperature less than 40°C, and stripped off with acetone (50ml). 6. The residue was stirred with acetone (Hit) at room temperature for 1 hour. 7. The solids were filtered and dried under vacuum at 50-55°C to obtain duloxetine base i Form A (25gm). Example 2 Preparation of duloxetine free base (Form B) 1. Duloxetine free base Form A (10g) was dissolved in methanol (250ml) at 55-60°C. 2. The solution was cooled to room temperature. 3. The solution was stirred at room temperature for 1 hour. 4. The solids were filtered and washed with methanol (10ml). 5. The solids were dried under vacuum at 50-55°C to give duloxetine free base Form B (7gm). Example 3 Preparation of duloxetine free base (Form C) 16 1. To Duloxetine (-) Di-p-toluyl tartarate (100gm), prepared by the above Reference Example, was charged water (1 lit), followed by stirring at 25-30°C for 15 minutes. 2. Slowly, lye solution (8gm sodium hydroxide in 50ml water) was added and stirred for 10-15 minutes at 25-30°C. 3. The mixture was extracted twice with methylene chloride (500ml). 4. Combined methylene chloride layers were washed with water (100ml). 5. Methylene chloride was distilled out under vacuum at a temperature less than 40°C, and stripped off with isopropanol (50ml). 6. The residue was stirred with isopropanol (500 ml) at room temperature for 1 hour. 7. The solids were filtered and dried under vacuum at 50-55°C to obtain duloxetine free base Form C (25gm). Example 4 Preparation of duloxetine hydrochloride 1. Duloxetine free base Form A (25gm) and acetone (250ml) were stirred for 15 minutes at 25-30°C 2. The pH of the mixture was adjusted to 2.0-3.0 using 20% isopropanolic HC1 at 25-30°C. 3. The solids were filtered, washed with acetone (100ml) and dried under vacuum at 50-55°C to give duloxetine hydrochloride (25gm). Example 5 Preparation of duloxetine hydrochloride In a manner analogous to Example 4, duloxetine free base rorm B was converted to duloxetine hydrochloride. Example 6 Duloxetine Capsules (Duloxetine base according to the present invention) - 60 me Sr. No Ingredients Qty (mg/capsule) 1. Drug Loading 1. Duloxetine 60 mgi 2. Non pareil seeds 110 - 140 mg 3. Hydroxy propyl methyl cellulose 2.0- 4.0 4. Talc 1.5- 2.8 5. Colloidal Silicon Dioxide 0.5- 1.5 6. Isopropyl Alcohol q.s 7. Methylene chloride q.s \|i II. Seal Coating j1 1. Hydroxy propyl methyl cellulose 7-1 0 2. Propylene Glycol 2-4 3. Talc 2-4 4. Isopropyl Alcohol q.s 5. Methylene chloride q.s III. Eudragit Coating ,-. 1. Eudragit L 100-55 10- 20 ■■•.-.. 2. Talc 4-8 3. Titanium dioxide 2-5 4. Triethyl citrate 1.5-3.0 5. Sodium hydroxide 0.1- 0.5 6. Purified water q.s Manufacturing process - Drug loading in glatt GPCG 1.1 by bottom spray. Example 7 Duloxetine Capsules (Duloxetine base according to the present invention) - 60 mg ■ Sr. No Ingredients Qty (mg/capsule) 1. Drug Loading ]. Duloxetine 60 mg 2. Non pareil seeds 110- 1JK) J. Hydroxy propyl methyl cellulose 2.0-4.0'1 4. Talc 1.5-15 5. Colloidal Silicon Dioxide 0.5- 1.5 6. Mannitol 60 mg 11. Seal Coating 1. Hydroxy propyl methyl cellulose 7-10 2. Mannitol 3.0-9.0 Talc 3.5-4.51 4. Propylene Glycol 1.5-151 5. Purified water q.s III. Eudragit Coating 1. Eudragit 9-11■ 2. Talc 2.0-4.0 Titanium dioxide 1.0-C .0 4. Triethyl citrate 1.0-3.C ) 5. Sodium hydroxide 0.1-0.3 5 6. Purified water q.s Manufacturing process - Drug loading in rotar coater. Example 8 Duloxetine Hydrochloride Capsules (Duloxetine hydrochloride as provided according to the present invention) - 60 mg Sr.No Ingredients Qty \| (mg//capsule) I. Drug Loading i 1. Duloxetine Hydrochloride 60m'gr 2. Non pareil seeds 110 — 140 mg J. Hydroxy propyl methyl cellulose 2.0-4 0 4. Talc 1.5-2 8 5. 6. Colloidal Silicon Dioxide 0.5-1 .5i Isopropyl Alcohol q.s 7. Methylene chloride q.s 11. Seal Coating 1.2. Hydroxy propyl methyl cellulose 7-10 Propylene Glycol 2-4 J). Talc 2-4 4. Isopropyl Alcohol q.s 5. Methylene chloride q.s III. Eudragit Coating 1. EudragitL 100-55 10-2( ) 2. Talc 4-8 3. Titanium dioxide 2-5 4. Triethyl citrate 1.5-3.01 5. Sodium hydroxide 0.1-0.5 6. Purified water q.s Manufacturing process – Drug loading in glatt GPCG 1.1 by bottom spray. Example 9 Duloxetine Hydrochloride Capsules (Duloxetine hydrochloride as provided according to the present invention) - 60 mg Sr.No Ingredients Qty(mg/ capsule) I. Drug Loading 1. Duloxetine Hydrochloride 60 rr g 2. Non pareil seeds 110- 140 J. Hydroxy propyl methyl cellulose 2.0-4.0 4. Talc 1.5-2.5 5. Colloidal Silicon Dioxide 0.5 - 1.5 6. Mannitol 60 mg 11. Seal Coating 1. Hydroxy propyl methyl cellulose 7- 10 2. Mannitol 3.0-910 Talc 3.5-4.5 4. Propylene Glycol 1.5-2.5 5. Purified water q.s III. Eudragit Coating 1. Eudragit 9-11 2. Talc 2.0-4.0 3. Titanium dioxide 1.0-3.0 4. Tiethyl citrate 1.0-3.0 5. Sodium hydroxide 0.1-0.3 6. Purified water q.s Example 10 Forced degradation study on duloxetine hydrochloride produced according to the prior art (Preparation 2, US 5,491,243) and duloxetine hydrochloride produced from crystalline duloxetine free base according to the present invention DULOXETINE HC1 (from prior DULOXETINE HC1 (from free STRESS CONDITION a rt) base) Description SMI Total Description SMI Total imp imp 1. Heat/UV a) Before White powder 0.20% 0.48% White 0.05% 0.11% exposure to powder heat or light b) 45°c Creamcolouredpowder 0.19% 0.65% White powder 0.07% 0.12% c) 60°c Light pink coloured 0.19% 0.70% White 0.07% 0.12% d)UV powderLight browncolouredpowder 0.19% 0.66% powderCreamcolouredpowder 0.06% 0.11% "SMI" - Single maximum impurity 22 CLAIMS 1. Duloxetine free base in crystalline form. 2. Crystalline duloxetine free base, Form A, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 1. 3. Crystalline duloxetine free base, Form A, characterised as having an X-ray diffraction pattern with characteristic peaks (29): 9.70, 10.88, 13.03, 15.61, 19.19, 19.55, 19.88, 21.94, 22.16, 26.95 and 27.76°. 4. Crystalline duloxetine free base, Form B, having an ^X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 2. 5. Crystalline duloxetine free base, Form B, characterised as having an X-ray diffraction pattern with characteristic peaks (29): 4.98, 9.96, 11.18, 12.58, 15.32, 18.98, 20.04, 20.62, 22.32, 22.44, 27.28 and 30.30°. 6. Crystalline duloxetine free base, Form C, having an! X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 3. 7. Crystalline duloxetine free base, Form C, characterised as having an X-ray diffraction pattern with characteristic peaks (20): 12.23, 13.49, 16.90, 18;.28, 20.37, 22.61, 27.22, 27.40 and 30.65°. 8. A pharmaceutically acceptable salt of duloxetine, which pharmaceutically acceptable salt is prepared from duloxetine free base in crystalline form according to any of claims 1 to 7. 9. A pharmaceutically acceptable salt according to claim 8, which is duloxetine hydrochloride. 23 10. A pharmaceutical^ acceptable salt according to claim 8, which is duloxetine oxalate. 11. A pharmaceutical^ acceptable salt according to any of claims 8 to 10, which is at least about 99.5% w/w pure. 12. A process of preparing crystalline duloxetine free base according to any of claims 1 to 7, from a duloxetine salt. 13. A process according to claim 12, wherein the salt is selected from the group consisting of duloxetine oxalate, duloxetine hydrochloride and duloxetine di-p-toluyl tartarate salt. 14. A process of preparing crystalline duloxetine free base according to any of claims 1 to 7, which process comprises dissolving or suspending a salt1 of duloxetine in a suitable medium, neutralizing with a suitable base, extracting the thus formed duloxetine free base into a suitable solvent, replacing the solvent with a non-solvent, and thus isolating duloxetine free base in crystalline form. 15. A process according to claim 14, wherein said medium comprises water. 16. A process according to claim 14 or 15, wherein said base comprises an alkali metal hydroxide. 17. A process according to claim 16, wherein said alkali metal hydroxide is sodium hydroxide. 18. A process of preparing crystalline duloxetine free base according to any of claims 1 to 7, which comprises a polymorph interconversion process wherein a second polymorphic form of crystalline duloxetine free base is prepared from a distinct first polymorphic form of crystalline duloxetine free base. 24 19. A process according to claim 18, wherein the first polymorphic form of crystalline duloxetine free base employed as the starting material of the interconversion process is dissolved in a suitable lower alcohol solvent, and the second polymorphic form is re-crystallized therefrom. 20. A process according to claim 19, wherein said lower alcohol solvent is methanol. 21. A process according to any of claims 18 to 20, wherein crystalline duloxetine free base Form B is prepared from crystalline duloxetine free base Form A. 22. A process of preparing crystalline duloxetine free base Form A according to claim 2 or 3, which process comprises suspending or dissolving a duloxetine salt in water, neutralizing with a base, extracting into a substantially! water immiscible solvent, concentrating the substantially water immiscible solvent, replacing the substantially water immiscible solvent with acetone and thus isolating duloxetine free base Form A in crystalline form. 23. A process according to claim 22, wherein said duloxetine salt is duloxetine hydrochloride or duloxetine di-p-toluyl tartarate. 24. A process according to claim 22 or 23, wherein said base is an alkali metal hydroxide. 25. A process according to claim 24, wherein said alkali metal hydroxide is sodium hydroxide. 26. A process according to any of claims 22 to 25, wherein\| said water immiscible solvent is dichloromethane. 27. A process of preparing crystalline duloxetine free base Form B according to claim 4 or 5, which process comprises dissolving or suspending duloxetine free base Form A in a lower alcohol solvent and recrystallizing duloxetine free base form B therefrom. 25 28. A process according to claim 27, wherein said lower alcohol solvent is methanol. 29. A process of preparing crystalline duloxetine free; base Form C, which process comprises suspending or dissolving a duloxetine salt in water, neutralizing with a base, extracting into a substantially water immiscible solvent, concentrating the substantially water immiscible solvent, replacing the substantially water immiscible solvent with isopropanol and thus isolating duloxetine free base Form C in crystalline form. 30. A process according to claim 29, wherein said duloxetine salt is duloxetine hydrochloride or duloxetine di-p-toluyl tartarate. 31. A process according to claim 29 or 30, wherein said base is an alkali metal hydroxide. 32. A process according to claim 31, wherein said alkali; metal hydroxide is sodium hydroxide. 33. A process according to any of claims 29 to 32, wherein said water immiscible solvent is dichloromethane. 34. A process of preparing a pharmaceutical^ acceptable salt of duloxetine according to any of claims 8 to 11, which comprises dissolving or suspending crystalline duloxetine free base according to any of claims 1 to 7 in a water miscible solvent, adding a pharmaceutical^ acceptable acid thereto required to form the pharmaceutically acceptable salt, and isolating the required pharmaceutical^ acceptable salt of duloxetine in crystalline form. 35. A process according to claim 34, wherein said crystalline duloxetine free base is Form A. 36. A process according to claim 34, wherein said crystalline duloxetine free base is Form B. 26 37. A process according to claim 34, wherein said crystalline! duloxetine free base is Form C. 38. A process according to any of claims 34 to 37, wherein said water miscible solvent is acetone. 39. A process according to any of claims 34 to 38, wherein said salt is duloxetine oxalate. 40. A process according to any of claims 34 to 38, wherein said salt is duloxetine hydrochloride. 41. A pharmaceutically acceptable formulation for administering to a patient, including humans, suffering from, or susceptible to, a disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor, which formulation comprises a therapeutically effective amount of crystalline duloxetine free base i according to any of claims 1 to 7, or a pharmaceutically acceptable salt of duloxetine according to any of claims 8 to 11, together with a pharmaceutically acceptable carrier, diluent or excipient therefor. 42. Crystalline duloxetine free base according to any of claims 1 to 7, or a pharmaceutically acceptable salt of duloxetine according to any of claims 8 to 11, for use in the manufacture of a medicament for the treatment of a disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor. 43. Crystalline duloxetine free base according to any of claims 1 to 7, or a pharmaceutically acceptable salt of duloxetine according to any of claims 8 to 11, for use in the manufacture of a medicament for the treatment of depression. 27 44 Duloxetine free base in crystalline form and process for preparing crystalline duloxetin free base, substantially as hereinbefore described with reference to the foregoing examples and accompanying drawings. Dated this 10th day of November 2006. (YIBHA SHUKLA) Of K & S PARTNERS AGENT FOR THE APPLICANTS ABSTRACT "PHARMACEUTICAL COMPOSITION AND POLYMORPHS THEREOF" The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof.

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
“CRYSTALLINE FORMS OF DULOXETINE FREE BASE"

CIPLA LIMITED
289 Bellasis Road, Mumbai Central, Mumbai 400 008, India
The following specification particularly describes the invention and the manner in which it is to be performed.

2
PHARMACEUTICAL COMPOUND AND POLYMORPHS THEREOF
The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof.
Duloxetine, N-methyl-3-(l-naphthalenyloxy)-3-(2-thienyl)propanamine, is a dual serotonin and norepinephrine reuptake inhibitor. (H-)Duloxetine has particular therapeutic utility as an anti-depressant.
Duloxetine, and the preparation thereof, is described1 in US patents 5023269 and 4956388, and also Tetrahedron Letters, 31, (49), 7101-04, 1990. Seven different routes of synthesis have also been reported in Drugs of the Future 2000, 25(9) 907-916. These syntheses have involved either a resolution of a key intermediate or a stereospecific reduction of a keto group to the alcohol.
Isolation of duloxetine free base in crystalline form has not, however, been achieved by any of the processes described in the reported literature and patents.
There is now provided by the present invention, however, duloxetine free base in crystalline form.
The present invention further provides processes of preparing three different
polymorphic forms of duloxetine, herein designated Forms A, B and C respectively, and
i these three polymorphic forms represent further embodiments jof the present invention. As
used herein, the term "duloxetine" preferably designates (+) duloxetine.
According to the present invention, there is provided crystalline duloxetine free base,
Form A, having an X-ray diffraction pattern, or substantially the same X-ray diffraction
pattern, as shown in Figure 1. More particularly, crystalline duloxetine free base Form A
i according to the present invention can be characterised as having an X-ray diffraction pattern
with characteristic peaks (20): 9.70, 10.88, 13.03, 15.61, 19.19, 19.55, 19.88, 21.94, 22.16,
26.95 and 27.76°.
Further characterising data for crystalline duloxetine free base Form A according to
the present invention as obtained by X-ray diffraction is shown in following table 1.

Table 1

Peak No. 29 (deg) FWHM (deg) d (A) Intensity (Counts) I/lo
1 9.700 0.212 9.1103 1107 27
2 10.880 0.188 8.1248 1372i 34'
3 12.050 0.165 7.3384 643 16
4 12.290 0.188 7.1956 721i 18
5 13.030 0.294 6.7886 154|8 38
6 13.910 0.129 6.3610 431 11
7 15.610 0.235 5.6719 243!2 59
8 17.300 0.188 5.1214 6521 16
9 17.770 0.318 4.9870 443 11
10 18.410 0.118 4.8151 599 15
11 19.030 0.153 4.6596 2632 64
12 19.190 0.235 4.6211 309,8 75
13 19.550 0.176 4.5368 2429 59
14 19.880 0.235 4.4622 4143 100
15 20.170 0.165 4.3987 1332 33
16 20.910 0.271 4.2447 1119 27
17 21.200 0.200 4.1873 11271 28
18 21.940 0.271 4.0477 3684i 89
19 22.160 0.200 4.0080' 3494 85
20 22.730 0.106 3.9088 584 15
21 23.290 0.165 3.8160 71j3 18
22 . 23.420 0.129 3.7951 673 17
23 23.660 0.165 3,7572 7l'8 18
24 24.350 0.235 3.6523 2351/ i 57
25 24.810 0.224 3.5856 969 24
26 25.280 0.129 3.5200 9501 23
27 25.460 0.188 3.4955 1042 .26

28 26.070 0.106 3.4151 53(3. 1 13
29 26.950 0.247 3.3055 1527 1 37
30 27.360 0.188 3.2569 1078 27
31 27.760 0.247 3.2109 1653 40
32 28.700 0.118 3.1078 6^8 16
33 29.460 0.318 3.0293 916i 23
34 29.930 0.365 2.9828 1118 27
35 30.970 0.106 2.8850 7631 19
36 31.130 0.188 2.8705 769 19
37 31.590 0.294 2.8298 1038 26
38 33.170 0.129 2.6985 5V 14
39 33.520 0.106 2.6711 646i 16
40 33.700 0.176 2.6573 668I 17
41 33.940 0.118 2.6390 626.i 16
42 34.860 0.306 2.5715 685 17
43 36.370 0.118 2.4681 816 20
44 36.740 0.271 2.4441 1052 26
45 37.150 0.118 2.4180 954 24
46 37.330 0.118 2.4068 9531 23
47 39.710 0.165 2.2679 806 20
48 40.090 0.176 2.2472 7381 18
49 40.700 0.118 2.2149 658 16
50 41.050 0.153 2.1969 766 19
51 41.610 0.106 2.1686 883 22 24
52 41.690 0.141 2.1646 962
53 42.290 0.118 2.1353 770 19
54 42.420 0.129 2.1290 818i 20
55 42.720 0.165 2.1148 692 17

According to the present invention, there is provided crystalline duloxetine free base, Form B, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 2. More particularly, crystalline duloxetine free base Form B according to the present invention can be characterised as having an X-ray diffraction pattern with characteristic peaks (29): 4.98, 9.96, 11.18, 12.58, 15.32, 18.98, 20.04, 20.62, 22.32, 22.44, 27.28 and 30.30°.
Further characterising data for crystalline duloxetine free base Form B according to the present invention as obtained by X-ray diffraction is shown1 in following table 2.
Table 2

Peak No. 29 (deg) FWHM (deg) d (A) Intensity (Counts) I/Io
1 4.980 0.188 17.7294 915 17
2 9.960 0.212 8.8731 1269 23
3 11.180 0.235 7.9074 2278 41
4 11.580 0.212 7.6352 749 14
5 12.580 0.259 7.0304 1131i 21
6 14.580 0.259 6.0702 576 11
7 15.320 0.282 5.7786 1767 32
8 17.860 0.118 4.9621 640i 12
9 17.980 0.141 4.9293 6^0 13
10 18.980 0.353 4.6717 3036 55
11 20.040 0.235 4.4270 5583 100
12 20.620 0.282 4.3037 17il6 31
13 21.000 0.306 4.2267 1383 25
14 22.320 0.306 3.9796 4190 76
15 22.440 0.141 3.9586 3576 65
16 23.220 0.141 3.8274 1435i 26
17 23.340 0.188 3.8080 1498 27
18 23.840 0.259 3.7292 1382 25

19 24.560 0.118 3.6215 726 13
20 25.000 0.165 3.5588 1010 19
21 25.160 '•'■ 0.400 3.5365 1089 20
22 27.280 0.400 3.2663 2364 43
23 27.760 0.306 3.2109 19961996 36
24 30.300 0.329 2.9473 2574 47
25 30.880 0.118 2.8932 944j 17
26 31.140 0.118 2.8696 921]i 17
27 31.840 0.141 2.8081 985] 18
28 32.000 0.165 2.7945 1003 18
29 32.180 0.118 2.7792 822| 15
30 36.760 0.212 2.4428 871 16
31 37.120 0.118 2.4199 1095 20
32 37.420 0.306 2.4012 1360 25
33 38.380 0.141 2.3433 860i 16
34 38.560 0.259 2.3328 890 16
According to the present invention, there is provided crystalline duloxetine free base, Form C, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 3. More particularly, crystalline duloxetine free base Form C according to the present invention can be characterised as having an X-ray diffraction pattern with characteristic peaks (20): 12.23, 13.49, 16.90, 18.28, 20.37, 22.61, 27.22, 27.40 and 30.65°.
Further characterising data for crystalline duloxetine free base Form C according to the present invention as obtained by X-ray diffraction is shown in following table 3.
Table 3

Peak No. 20 (deg) FWHM (deg) d (A) Intensity (Counts) l/Io
1 11.160 0.306 7.9215 \9\\ 51

2 12.230 0.318 7.2308 919! 25
3 ' 12.570 0.224 7.0360 872 23
4 13.490 : 0.400 6.5581 1419 38
5 15.050 0.341 5.8817 6J10 17
6 16.900 0.282 5.2417 850i 23
7 18.280 0.400 4.8490 1717 46
8 18.840 0.388 4.7061 16461 44
9 19.500 0.106 4.5483 941 25
10 19.660 0.129 4.5117 1141i 30
11 20.370 0.424 4.3560 3573 94
12 20.810 0.271 4.2649 1890i 50
13 21.710 0.106 4.0900 6;37 17
14 22.610 0.424 3.9292 38081 100
15 23.080 0.212 3.8503 1206 32
16 23.850 0.247 3.7277 ■7j25 20
17 25.140 0.318 3.5393 958 26
18 25.570 0.318 3.4807 1065 28
19 27.220 0.141 3.2733 1534 41
. 20 27.400 0.400 3.2522 1778 47
21 27.830 0.129 3.2030 7^6 21
22 28.030 0.129 3.1806 704 19
23 28.440 0.224 3.1356 696 19
24 29.730 0.153 3.0024 696i 19
25 30.180 0.129 2.9587 989I 26
26 30.650 0.471 2.9144 1636I 43
27 32.340 0.129 2.7658 746i 20
28 32.530 0.224 2:7501 836 22
29 34.420 0.200 2.6033 708i 19
30 34.900 0.118 2.5686 760 20
31 35.080 0.188 2.5558 787i 21
32 36.730 0.235 2.4447 8151 22

33 - 36.990 0.106 2.4281 785 21
34 37.230 0.271 2.4130 812 22
35 40.430 0.106 2.2291 796 21
36 40.600 0.176 2.2202 8J13 22 ._
37 42.970 0.306 2.1030 1057
There is also provided by the present invention a pharmaceutical^ acceptable salt of dluloxetine, which pharmaceutical^ acceptable salt is prepared from duloxetine free base in crystalline form as provided by the present invention. Preferred pharmaceutical^ acceptable salts of duloxetine as provided by the present invention include |duloxetine hydrochloride and dluloxetine oxalate, especially duloxetine hydrochloride.
A pharmaceutical^ acceptable salt of duloxetine as provided by the present invention is preferably at least about 99.5% w/w pure.
Crystalline duloxetine free base as provided by the present invention can in turn be prepared from salts of duloxetine, such as the oxalate salt, hydrochloride salt, di-p-toluyl tartrate salt, or any other suitable salt. According to the present invention, there is further provided a process of preparing crystalline duloxetine free base, which process comprises dissolving or suspending a salt of duloxetine in a suitable medium, such as water, neutralizing with a suitable base, such as an alkali metal hydroxide, (typically sodium hydroxide, extracting the thus formed duloxetine free base into a suitable Isolvent, replacing the solvent with a non-solvent, and thus isolating duloxetine free base in crystalline form.
It is also possible to interconvert distinct polymorphic forms of crystalline duloxetine
■
free base as provided by the present invention. There is, therefore, further provided by the present invention an interconversion process, whereby a second polymorphic form of crystalline duloxetine free base is prepared from a distinct first polymorphic form of crystalline duloxetine free base. Suitably, the first polymorphic form of crystalline duloxetine free base which is employed as the starting material! is dissolved or suspended in a suitable lower alcohol solvent, preferably methanol, and the second polymorphic form is re-crystallized therefrom. Preferably, this interconversion process is employed for the preparation of crystalline duloxetine free base Form B from Form A substantially as hereinafter described in further detail.

9
The preparation of crystalline duloxetine free base according to the present invention is advantageous in that crystalline duloxetine free base can be employed as a useful intermediate in the preparation of highly pure pharmaceutically acceptable salts of duloxetine, in particular duloxetine oxalate or hydrochloride. Pharmaceutically acceptable salts of duloxetine prepared from crystalline duloxetine free! base can exhibit beneficial properties, for example, duloxetine hydrochloride prepared from crystalline duloxetine free base as provided by the present invention is more resistant to! degradation than duloxetine hydrochloride prepared by conventional methods known from the prior art.
According to the present invention there is further provided a process of preparing crystalline duloxetine free base Form A, which process comprises suspending or dissolving a duloxetine salt, such as the hydrochloride or di-p-toluyl tartarate salt of duloxetine, in water, neutralizing with a base, such as an alkali metal hydroxide, typically sodium hydroxide,
extracting into a substantially water immiscible solvent,! such as dichloromethane,
I concentrating the substantially water immiscible solvent, replacing the substantially water
immiscible solvent with acetone and thus isolating duloxetine free base Form A in crystalline
form. Crystalline duloxetine free base Form A is characterized by powder x-ray diffraction
substantially as shown in Figure 1.
According to the present invention there is further provided a process of preparing
crystalline duloxetine free base Form B, which process comprises dissolving or suspending a
first polymorphic form of crystalline duloxetine free base, typically duloxetine free base
Form A, in a suitable lower alcohol solvent, preferably methanol, and recrystallizing
i duloxetine free base Form B therefrom. Crystalline duloxetine free base Form B is
characterized by powder x-ray diffraction substantially as shown in Figure 2.
According to the present invention there is further prqvided a process of preparing
crystalline duloxetine free base Form C, which process comprises suspending or dissolving a
duloxetine salt, such as the hydrochloride or di-p-toluyl tartarate salt of duloxetine, in water,
neutralizing with a base, such as an alkali metal hydroxide,] typically sodium hydroxide,
extracting into a substantially water immiscible solvent, such as dichloromethane,
concentrating the substantially water immiscible solvent, replacing the substantially water
immiscible solvent with isopropanol and thus isolating duloxetine free base Form C in
crystalline form. Crystalline duloxetine free base Form C is characterized by powder x-ray
diffraction substantially as shown in Figure 3.

10
There is also provided by the present invention , a process of preparing a pharmaceutical^ acceptable salt of duloxetine, which process comprises dissolving or suspending crystalline duloxetine free base as provided by the; present invention in a water miscible solvent, such as acetone, adding a pharmaceutically acceptable acid thereto required to form the pharmaceutically acceptable salt, and isolating the required pharmaceutically acceptable salt of duloxetine in crystalline form. Any of polymorphic forms A, B or C of crystalline duloxetine free base as provided by the present invention can be employed as crystalline duloxetine free base starting material for the above process of preparing a pharmaceutically acceptable salt of duloxetine.
Suitable acid addition salts which can be prepared from crystalline duloxetine free base according to the present invention include those formed with pharmaceutically acceptable organic or inorganic acids and are well known to those of skill in the art. Acids commonly employed to form such salts include inorganic acids such as hydrochloric, hydrobromic, hydroiodic, sulfuric and phosphoric acid, as well as organic acids such as para-toluenesulfonic, methanesulfonic, oxalic, para-bromophenylsulfonic, carbonic, succinic, citric, benzoic and acetic acid, and related inorganic! and organic acids. Such pharmaceutically acceptable salts thus include sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, isobutyrate, caprate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, butyne-l,4-dioate, hexyne-l,6-dioate, benzoate, chlorobenzoate, methylbenzoate, dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, terephathalate, sulfonate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, 3-hydroxybutyrate, glycollate, maleate, tartrate, methanesulfonate, propanesulfonates, naphthalene-1-sulfonate, naphthalene-2-sulfonate, mandelate and the like salts. Preferred pharmaceutically acceptable acid addition salts include those formed with mineral acids such as hydrochloric acid and hydrobromic acid, and those formed with organic acids such as oxalic acid and maleic acid. A particularly preferred acid addition salt is the hydrochloride.
As noted above, duloxetine is a dual serotonin and norepinephrine reuptake inhibitor.
i
The present invention further provides a pharmaceutically acceptable formulation for administering to a patient, including humans, suffering from, or susceptible to, a disease state

11
prevented, ameliorated or eliminated by the administration of a serotonin and / or
norepinephrine reuptake inhibitor, which formulation comprises a therapeutically effective
amount of crystalline duloxetine free base, optionally as any of Forms A, B or G,
substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as
provided by the present invention substantially as hereinbefore described, together with a
pharmaceutically acceptable carrier, diluent or excipient therefor.
As used herein, the term "therapeutically effective amount" means an amount of
crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as
i hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the
present invention substantially as hereinbefore described, which is capable of preventing,
ameliorating or eliminating a disease state for which administration of a serotonin and / or
norepinephrine reuptake inhibitor is indicated.
By "pharmaceutically acceptable formulation" it is meant that the carrier, diluent or excipient is compatible with crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, and not deleterious to a recipient thereof.
Pharmaceutical formulations as provided by the present invention can be prepared by
known procedures using well known and readily available ingredients. In preparation of
formulations as provided by the present invention, crystalline duloxetine free base, optionally
as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically
acceptable salt of duloxetine as provided by the present invention substantially as
hereinbefore described, can be mixed with a carrier, diluent or excipient therefor.
Formulations as provided by the present invention can be I in the form of tablets, pills,
powders, lozenges, sachets, cachets, elixirs, suspensions, jemulsions, solutions, syrups,
i aerosol, ointments containing, for example, up to 10% by weight of crystalline duloxetine
free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a
pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, soft and hard gelatin icapsules, suppositories, sterile injectable solutions and sterile packaged powders. In particular, capsules are suitable formulations for use in accordance with the present invention, which can typically include

12-
coated non pareil seeds substantially as hereinafter illustrated in further detail by reference to the Examples.
Some examples of suitable carriers, excipients. and diluents include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth,
gelatin, calcium silicate, microcrystalline cellulose, polyviny syrup, methyl cellulose, methyl- and propylhydroxybenzoates, mineral oil. The formulations can additionally include lubricating agents, wetting agents, emulsifying and suspending agents, preserving agents, sweetening agents or flavoring agents. The formulations of the invention may be formulated so as to provide quick, sustained or delayed release of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, after administration to the patient by employing procedures well known in the art.
The formulations are preferably formulated in a unit dosage form, each dosage containing1 from about 5 to about 500 mg, more usually about 25 to about 300 mg, of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described,. The term "unit dosage form" refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical carrier.
There is also provided by the present invention crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, for use in therapy.
The present invention further provides crystalline duloxetine free base, optionally as
any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically
acceptable salt of duloxetine as provided by the present invention substantially as
hereinbefore described, for use in the manufacture of a medicament for the treatment of a
. ■ I
disease state prevented, ameliorated or eliminated by the administration of a serotonin and /
or norepinephrine reuptake inhibitor as described herein.

13
The present invention also provides a method of treating a disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor in a patient in need of such treatment, which method comprises administering to the patient a therapeutically effective amount of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described.
A variety of physiologic functions have been shown I to be subject to influence by brain serotoninengic and norepinephrinergic neural systems. As such, crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, of the present invention, or a pharmaceutically acceptable salt of] duloxetine as provided by the present invention substantially as hereinbefore described, has utility in the treatment of a variety of disorders in mammals associated with these initial systems such as obesity, depression, alcoholism, pain, loss of memory, anxiety and smoking. In particular, crystalline duloxetine free base, optionally as any of Forms A, B or C[ substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, has utility in the treatment of depression.
In a preferred aspect of the present invention, therefore, there is provided crystalline duloxetine free base, optionally as any of Forms A, B or CJ, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, for use in the manufacture of a medicament for the treatment of depression.
In a preferred aspect of the present invention, therefore, there is also provided a
method of treating depression in a patient in need of such treatment, which method comprises
j administering to the patient a therapeutically effective amount of crystalline duloxetine free
base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a
pharmaceutically acceptable salt of duloxetine as provided by the present invention
substantially as hereinbefore described.
The particular dose of crystalline duloxetine free base, optionally as any of Forms A,
B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of
duloxetine as provided by the present invention substantially as hereinbefore described,
administered according to this invention will of course be determined by the particular

14
circumstances surrounding the case, the route of administration, the particular condition being treated, and similar considerations. Crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described, can be administered by a variety of routes including the oral, rectal, transdermal, subcutaneous, intravenous, intramuscular or intranasal routes. A typical daily dose will contain from about 0.01 mg/kg to about 20 mg/kg of crystalline duloxetine free base, optionally as any of Forms A, B or C, substantially as hereinbefore described, of the present invention, or a pharmaceutically acceptable salt of duloxetine as provided by the present invention substantially as hereinbefore described,. Preferred dai y doses will be about 0.05 to about 10 mg/kg, ideally about 0.1 to about 5 mg/kg.
The present invention will now be further illustrated by the Figures and following Examples, which do not limit the scope of the invention in any way.
Figure 1 is a powder X-ray diffraction pattern for crystalline duloxetine free base Form A.
Figure 2 is a powder X-ray diffraction pattern for crystalline duloxetine free base Form B.
Figure 3 is a powder X-ray diffraction pattern for crystalline duloxetine free base Form C.
The above referred to X-ray diffraction patterns were obtained on a Rigaku Miniflex X-ray Diffractometer equipped with a Cu Ka source and a scintillation counter detector. The scan speed was 2 degrees per minute and the range was from 3 to 45 degrees.
Examples
Reference Example - Preparation of duloxetine (-~)di-p-toluyl tai tarate
1. Racemic Duloxetine (100gm) was added to methanol (200ml).
2. (-) Di-p-Toluoyl-L-Tartaric acid (130gm) was added lotwise at 25-30°C.
3. The contents were heated to 60-65°C and maintained for 1 hour at 60-65°C.
4. Methanol was completely distilled under vacuum at 45-50°C.

5. Acetone (1.5lit) was added to the residue and stirred for 3 hours at 25-30°C.
6. The solids were filtered, washed with acetone (100ml) and dried under vacuum at 45-50°C to give the title compound (80gm).
Example 1
Preparation of duloxetine free base (Form A)
1. To Duloxetine (-) Di-p-toluyl tartarate (100gm), prepared by the above Reference
i
Example, was charged water (Hit), followed by stirring at 25-30°C for 15 minutes.
2. Slowly, lye solution (8gm sodium hydroxide in 50ml water) was added and stirred for 10-15 minutes at 25-30°C.
3. The mixture was extracted twice with methylene chloride (500ml).
4. Combined methylene chloride layers were washed with water (100ml).
5. Methylene chloride was distilled out under vacuum at a temperature less than 40°C, and stripped off with acetone (50ml).
6. The residue was stirred with acetone (Hit) at room temperature for 1 hour.
7. The solids were filtered and dried under vacuum at 50-55°C to obtain duloxetine base
i
Form A (25gm).
Example 2
Preparation of duloxetine free base (Form B)
1. Duloxetine free base Form A (10g) was dissolved in methanol (250ml) at 55-60°C.
2. The solution was cooled to room temperature.
3. The solution was stirred at room temperature for 1 hour.
4. The solids were filtered and washed with methanol (10ml).
5. The solids were dried under vacuum at 50-55°C to give duloxetine free base Form B (7gm).
Example 3
Preparation of duloxetine free base (Form C)

16
1. To Duloxetine (-) Di-p-toluyl tartarate (100gm), prepared by the above Reference Example, was charged water (1 lit), followed by stirring at 25-30°C for 15 minutes.
2. Slowly, lye solution (8gm sodium hydroxide in 50ml water) was added and stirred for 10-15 minutes at 25-30°C.
3. The mixture was extracted twice with methylene chloride (500ml).
4. Combined methylene chloride layers were washed with water (100ml).
5. Methylene chloride was distilled out under vacuum at a temperature less than 40°C, and stripped off with isopropanol (50ml).
6. The residue was stirred with isopropanol (500 ml) at room temperature for 1 hour.
7. The solids were filtered and dried under vacuum at 50-55°C to obtain duloxetine free base Form C (25gm).
Example 4
Preparation of duloxetine hydrochloride
1. Duloxetine free base Form A (25gm) and acetone (250ml) were stirred for 15 minutes at 25-30°C
2. The pH of the mixture was adjusted to 2.0-3.0 using 20% isopropanolic HC1 at 25-30°C.
3. The solids were filtered, washed with acetone (100ml) and dried under vacuum at 50-55°C to give duloxetine hydrochloride (25gm).
Example 5
Preparation of duloxetine hydrochloride
In a manner analogous to Example 4, duloxetine free base rorm B was converted to duloxetine hydrochloride.
Example 6
Duloxetine Capsules (Duloxetine base according to the present invention) - 60 me

Sr. No Ingredients Qty (mg/capsule)
1. Drug Loading
1. Duloxetine 60 mgi
2. Non pareil seeds 110 - 140 mg
3. Hydroxy propyl methyl cellulose 2.0- 4.0
4. Talc 1.5- 2.8
5. Colloidal Silicon Dioxide 0.5- 1.5
6. Isopropyl Alcohol q.s
7. Methylene chloride q.s |i
II. Seal Coating j1
1. Hydroxy propyl methyl cellulose 7-1 0
2. Propylene Glycol 2-4
3. Talc 2-4
4. Isopropyl Alcohol q.s
5. Methylene chloride q.s
III. Eudragit Coating ,-.
1. Eudragit L 100-55 10- 20 ■■•.-..
2. Talc 4-8
3. Titanium dioxide 2-5
4. Triethyl citrate 1.5-3.0
5. Sodium hydroxide 0.1- 0.5
6. Purified water q.s
Manufacturing process - Drug loading in glatt GPCG 1.1 by bottom spray.
Example 7
Duloxetine Capsules (Duloxetine base according to the present invention) - 60 mg
■

Sr. No Ingredients Qty
(mg/capsule)

1. Drug Loading
]. Duloxetine 60 mg
2. Non pareil seeds 110- 1JK)
J. Hydroxy propyl methyl cellulose 2.0-4.0'1
4. Talc 1.5-15
5. Colloidal Silicon Dioxide 0.5- 1.5
6. Mannitol 60 mg
11. Seal Coating
1. Hydroxy propyl methyl cellulose 7-10
2. Mannitol 3.0-9.0
Talc 3.5-4.51
4. Propylene Glycol 1.5-151
5. Purified water q.s
III. Eudragit Coating
1. Eudragit 9-11■
2. Talc 2.0-4.0
Titanium dioxide 1.0-C .0
4. Triethyl citrate 1.0-3.C )
5. Sodium hydroxide 0.1-0.3 5
6. Purified water q.s
Manufacturing process - Drug loading in rotar coater.
Example 8
Duloxetine Hydrochloride Capsules (Duloxetine hydrochloride as provided according to the
present invention) - 60 mg

Sr.No Ingredients Qty | (mg//capsule)
I. Drug Loading i
1. Duloxetine Hydrochloride 60m'gr

2. Non pareil seeds 110 — 140 mg
J. Hydroxy propyl methyl cellulose 2.0-4 0
4. Talc 1.5-2 8
5. 6. Colloidal Silicon Dioxide 0.5-1 .5i
Isopropyl Alcohol q.s
7. Methylene chloride q.s
11. Seal Coating
1.2. Hydroxy propyl methyl cellulose 7-10
Propylene Glycol 2-4
J). Talc 2-4
4. Isopropyl Alcohol q.s
5. Methylene chloride q.s
III. Eudragit Coating
1. EudragitL 100-55 10-2( )
2. Talc 4-8
3. Titanium dioxide 2-5
4. Triethyl citrate 1.5-3.01
5. Sodium hydroxide 0.1-0.5
6. Purified water q.s
Manufacturing process – Drug loading in glatt GPCG 1.1 by bottom spray.
Example 9
Duloxetine Hydrochloride Capsules (Duloxetine hydrochloride as provided according to the
present invention) - 60 mg

Sr.No Ingredients Qty(mg/ capsule)
I. Drug Loading
1. Duloxetine Hydrochloride 60 rr g
2. Non pareil seeds 110- 140

J. Hydroxy propyl methyl cellulose 2.0-4.0
4. Talc 1.5-2.5
5. Colloidal Silicon Dioxide 0.5 - 1.5
6. Mannitol 60 mg
11. Seal Coating
1. Hydroxy propyl methyl cellulose 7- 10
2. Mannitol 3.0-910
Talc 3.5-4.5
4. Propylene Glycol 1.5-2.5
5. Purified water q.s
III. Eudragit Coating
1. Eudragit 9-11
2. Talc 2.0-4.0
3. Titanium dioxide 1.0-3.0
4. Tiethyl citrate 1.0-3.0
5. Sodium hydroxide 0.1-0.3
6. Purified water q.s

Example 10
Forced degradation study on duloxetine hydrochloride produced according to the prior art (Preparation 2, US 5,491,243) and duloxetine hydrochloride produced from crystalline duloxetine free base according to the present invention

DULOXETINE HC1 (from prior DULOXETINE HC1 (from free
STRESS CONDITION a rt) base)
Description SMI Total Description SMI Total
imp imp
1. Heat/UV
a) Before White powder 0.20% 0.48% White 0.05% 0.11%
exposure to powder
heat or light
b) 45°c Creamcolouredpowder 0.19% 0.65% White powder 0.07% 0.12%
c) 60°c Light pink coloured 0.19% 0.70% White 0.07% 0.12%
d)UV powderLight browncolouredpowder 0.19% 0.66% powderCreamcolouredpowder 0.06% 0.11%
"SMI" - Single maximum impurity

22
CLAIMS
1. Duloxetine free base in crystalline form.
2. Crystalline duloxetine free base, Form A, having an X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 1.
3. Crystalline duloxetine free base, Form A, characterised as having an X-ray diffraction pattern with characteristic peaks (29): 9.70, 10.88, 13.03, 15.61, 19.19, 19.55, 19.88, 21.94, 22.16, 26.95 and 27.76°.
4. Crystalline duloxetine free base, Form B, having an ^X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 2.
5. Crystalline duloxetine free base, Form B, characterised as having an X-ray diffraction pattern with characteristic peaks (29): 4.98, 9.96, 11.18, 12.58, 15.32, 18.98, 20.04, 20.62, 22.32, 22.44, 27.28 and 30.30°.
6. Crystalline duloxetine free base, Form C, having an! X-ray diffraction pattern, or substantially the same X-ray diffraction pattern, as shown in Figure 3.
7. Crystalline duloxetine free base, Form C, characterised as having an X-ray diffraction pattern with characteristic peaks (20): 12.23, 13.49, 16.90, 18;.28, 20.37, 22.61, 27.22, 27.40 and 30.65°.
8. A pharmaceutically acceptable salt of duloxetine, which pharmaceutically acceptable salt is prepared from duloxetine free base in crystalline form according to any of claims 1 to 7.
9. A pharmaceutically acceptable salt according to claim 8, which is duloxetine hydrochloride.

23
10. A pharmaceutical^ acceptable salt according to claim 8, which is duloxetine oxalate.
11. A pharmaceutical^ acceptable salt according to any of claims 8 to 10, which is at least about 99.5% w/w pure.
12. A process of preparing crystalline duloxetine free base according to any of claims 1 to 7, from a duloxetine salt.
13. A process according to claim 12, wherein the salt is selected from the group consisting of duloxetine oxalate, duloxetine hydrochloride and duloxetine di-p-toluyl tartarate salt.
14. A process of preparing crystalline duloxetine free base according to any of claims 1 to 7, which process comprises dissolving or suspending a salt1 of duloxetine in a suitable medium, neutralizing with a suitable base, extracting the thus formed duloxetine free base into a suitable solvent, replacing the solvent with a non-solvent, and thus isolating duloxetine free base in crystalline form.
15. A process according to claim 14, wherein said medium comprises water.
16. A process according to claim 14 or 15, wherein said base comprises an alkali metal hydroxide.
17. A process according to claim 16, wherein said alkali metal hydroxide is sodium hydroxide.
18. A process of preparing crystalline duloxetine free base according to any of claims 1 to 7, which comprises a polymorph interconversion process wherein a second polymorphic form of crystalline duloxetine free base is prepared from a distinct first polymorphic form of crystalline duloxetine free base.

24
19. A process according to claim 18, wherein the first polymorphic form of crystalline duloxetine free base employed as the starting material of the interconversion process is dissolved in a suitable lower alcohol solvent, and the second polymorphic form is re-crystallized therefrom.
20. A process according to claim 19, wherein said lower alcohol solvent is methanol.
21. A process according to any of claims 18 to 20, wherein crystalline duloxetine free base Form B is prepared from crystalline duloxetine free base Form A.
22. A process of preparing crystalline duloxetine free base Form A according to claim 2 or 3, which process comprises suspending or dissolving a duloxetine salt in water, neutralizing with a base, extracting into a substantially! water immiscible solvent, concentrating the substantially water immiscible solvent, replacing the substantially water immiscible solvent with acetone and thus isolating duloxetine free base Form A in crystalline form.
23. A process according to claim 22, wherein said duloxetine salt is duloxetine hydrochloride or duloxetine di-p-toluyl tartarate.
24. A process according to claim 22 or 23, wherein said base is an alkali metal hydroxide.
25. A process according to claim 24, wherein said alkali metal hydroxide is sodium hydroxide.
26. A process according to any of claims 22 to 25, wherein| said water immiscible solvent is dichloromethane.
27. A process of preparing crystalline duloxetine free base Form B according to claim 4 or 5, which process comprises dissolving or suspending duloxetine free base Form A in a lower alcohol solvent and recrystallizing duloxetine free base form B therefrom.

25
28. A process according to claim 27, wherein said lower alcohol solvent is methanol.
29. A process of preparing crystalline duloxetine free; base Form C, which process comprises suspending or dissolving a duloxetine salt in water, neutralizing with a base, extracting into a substantially water immiscible solvent, concentrating the substantially water immiscible solvent, replacing the substantially water immiscible solvent with isopropanol and thus isolating duloxetine free base Form C in crystalline form.
30. A process according to claim 29, wherein said duloxetine salt is duloxetine hydrochloride or duloxetine di-p-toluyl tartarate.
31. A process according to claim 29 or 30, wherein said base is an alkali metal hydroxide.
32. A process according to claim 31, wherein said alkali; metal hydroxide is sodium hydroxide.
33. A process according to any of claims 29 to 32, wherein said water immiscible solvent is dichloromethane.
34. A process of preparing a pharmaceutical^ acceptable salt of duloxetine according to any of claims 8 to 11, which comprises dissolving or suspending crystalline duloxetine free base according to any of claims 1 to 7 in a water miscible solvent, adding a pharmaceutical^ acceptable acid thereto required to form the pharmaceutically acceptable salt, and isolating the required pharmaceutical^ acceptable salt of duloxetine in crystalline form.
35. A process according to claim 34, wherein said crystalline duloxetine free base is Form A.
36. A process according to claim 34, wherein said crystalline duloxetine free base is Form B.
26
37. A process according to claim 34, wherein said crystalline! duloxetine free base is Form C.
38. A process according to any of claims 34 to 37, wherein said water miscible solvent is acetone.
39. A process according to any of claims 34 to 38, wherein said salt is duloxetine oxalate.
40. A process according to any of claims 34 to 38, wherein said salt is duloxetine hydrochloride.
41. A pharmaceutically acceptable formulation for administering to a patient, including humans, suffering from, or susceptible to, a disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor, which
formulation comprises a therapeutically effective amount of crystalline duloxetine free base
i
according to any of claims 1 to 7, or a pharmaceutically acceptable salt of duloxetine according to any of claims 8 to 11, together with a pharmaceutically acceptable carrier, diluent or excipient therefor.
42. Crystalline duloxetine free base according to any of claims 1 to 7, or a pharmaceutically acceptable salt of duloxetine according to any of claims 8 to 11, for use in the manufacture of a medicament for the treatment of a disease state prevented, ameliorated or eliminated by the administration of a serotonin and / or norepinephrine reuptake inhibitor.
43. Crystalline duloxetine free base according to any of claims 1 to 7, or a pharmaceutically acceptable salt of duloxetine according to any of claims 8 to 11, for use in the manufacture of a medicament for the treatment of depression.

27
44 Duloxetine free base in crystalline form and process for preparing crystalline duloxetin free base, substantially as hereinbefore described with reference to the foregoing examples and accompanying drawings.
Dated this 10th day of November 2006.

(YIBHA SHUKLA)
Of K & S PARTNERS AGENT FOR THE APPLICANTS

ABSTRACT
"PHARMACEUTICAL COMPOSITION AND POLYMORPHS THEREOF"
The present invention is concerned with duloxetine free base in crystalline form, and also novel polymorphic forms thereof.

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Patent Number

239496

Indian Patent Application Number

1341/MUMNP/2006

PG Journal Number

14/2010

Publication Date

02-Apr-2010

Grant Date

23-Mar-2010

Date of Filing

13-Nov-2006

Name of Patentee

CIPLA LIMITED

Applicant Address

289 Bellasis Road, Mumbai Central, Mumbai-400 008,

Inventors:

#	Inventor's Name	Inventor's Address
1	KANKAN, Rajendra, Narayanrao	A-3/5, NBD Society, NSS Road, Ghatkopar (West) Mumbai 400 084
2	RAO, Dharmaraj, Ramachandra	4/403 Garden Enclave, Pokhram Road 2, Thane West, Mumbai 400 601
3	SRINIVAS, Pathi, Laxminarayan	2475/24, 7th B Main, R P C Layout, Viajynagar, Bangalore 560 040,
4	RAVIKUMAR, Puppala	House No.5, A Cross, Vijaya Bank Colony, Banaswadi, Bangalore

PCT International Classification Number

C07D333/20

PCT International Application Number

PCT/GB2005/001825

PCT International Filing date

2005-05-11

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA