Title of Invention

A METHOD FOR SOLUBILISING FORSKOLIN

Abstract The present invention relates to a soiubilized diterpene based composition, said composition comprising forskolin ranging between 0.09% and 6% w/v and randomly-methylated P-cyclodextrins ranging between 5% and 70%, optionally along with excipients; and a method for solubilising forskolin.
Full Text

Field of Invention:
The present invention provides a novel method for preparation of a Forskolin based solution for convenient use in ophthalmic preparations for humans and for veterinary purposes.
Description of Prior Art:
Certain active pharmaceutical ingredients are inherently insoluble or very sparingly soluble in water or in aqueous vehicles. Very often their intended use may require their application in water or in aqueous vehicles. To achieve therapeutically active concentrations of such water insoluble active pharmaceutical ingredients in stable form has always been actively pursued. While the technique of molecular structural manipulation of the active pharmaceutical ingredient that is insoluble in water could be adopted, incorporating structural features that promote aqueous solubility may result in the attenuation or modification of the intended desired pharmacological properties. Hence it maybe most desirable to invent methods of solubilizing the active ingredients in their native structural form by other means.
Aqueous solubility of drugs is a desirable feature from many angles. Aqueous formulations are sterilizable by standard techniques such as filtration etc to render such preparations suitable for systemic administration. Also aqueous preparations are preferable in dermatological, gynecological, otological, rhinological and on mucous membrane applications. Especially useful are aqueous ophthalmic preparations of drugs.
Forskolin (CAS no 66575-29-9) is a naturally occurring labdane diterpene from Coleus forskohlii (Bhat, S.V.; Bajwa, B. S.; Domauer, H.; de Souza, N. J.; Fehlabar, H.-W.; Tetrahedron Lett., (1977), 18,1669). It has several desirable pharmacological properties.
Forskolin displays positive inotropic, antihypertensive and broncho-spasmolytic activity; (Bhat, S.V.; Dohadwalla, A. N.; Bajwa, B. S.; Dadkar, N.; Domauer, H.; de Souza, N. J.; J Med Chem., (1983), 26, 486).

It lowers intraocular pressure (Caprioh J, Sears M.; Lancet (1983); Apr 30;1(8331):958-60; . Badian M et al.; Klin Monatsbl Augenheilkd (1984);185:5226, Zeng S, et al. Yan Ke Xue Bao (1995);11:173-176, Lee PY , et al.; Arch Ophthalmol (1987);105:249-252, . Meyer BH, et al. S Afr Med J. (1987);71:570-571; Seto C, et al.; Jpn J Ophthalmol (1986);30:238-244.; Burstein Nl et al. Exp Eye Res (1984);39:745-749; Brubaker RF et al. Arch Ophthalmol (1987);105:637-641).
Diverse biological activities are observed by raising the levels of cAMP, and as a result activating protein kinase. Such properties have led to numerous uses of Forskolin. Due to such activities, more than 1500 citations dealing with the physiological properties of Forskolin appeared in Chemical Abstracts in 2001. However, Forskolin is highly insoluble in water.
Intensive efforts have been made on the molecular manipulation of Forskolin to make such derivatives of Forskolin as will be water soluble. Such attempts have always met with mixed success ( Lai, B.; Gangopadhyay, A. K.; Rajagopalan, R.; Ghate, A. V.; Bioorganic & Medicinal Chemistry, (1998), 6(11), 2061-2073; Lai, B.; Gangopadhyay, A. K.; Gidwani, R. M.; Fernandez, M.; Rajagopalan, R.; Ghate, A. V.; Bioorganic & Medicinal Chemistry, (1998), 6(11), 2075-2083).
As an alternative to chemical manipulations of the drug molecular structure, physicochemical techniques of enhancing the solubility of the underivatized drug in water have been employed. Notable technologies include micellar solubilization using surface active ingredients, which will form water soluble micelles containing the drug. Another related technique is complexation of the drug molecule with a host molecule. The host molecule is usually one that has good solubility in water. The host molecule does not form any covalent bonds with the drug molecule but forms a weak complex through non-covalent interactions and the host molecule(s) keep the drug molecule(s) in water solution.

Cyclodextrins are cyclic oligosaccharides which have been recognized as useful pharmaceutical excipients. The common cylcodextrins are called α-, β-, 7- and 5-cyclodextrins depending on the number of glucose molecules in the cyclic oligosaccharide structure. These cyclodextrins are (α-1, 4)-linked oligosaccharides of α-D-glucopyranose containing a relatively hydrophobic central cavity and hydrophilic outer surface. These molecules are not exactly perfect cylinders due to restriction of completely free rotation about their linking bonds of the units of the sugar molecule. They assume the shape of a torus or a truncated cone. The secondary hydroxyl groups line the wider edge of the rim while the primary hydroxyl groups line the narrow side of the torus. The solubilities of these molecules in water and the diameter of the central cavity have been known and pubUshed ( Loftsson, T.; Brewster, M. E.; J Pharmaceutical Sciences, (1996), 85, 1017 & Rajewski, R. A.; Stella, V. J.; J Pharmaceutical Sciences, (1996), 85, 1142). The structure of jβ-cyclodextrin containing seven glucose units is shown as an example


7- and 8- cyclodextrins are sometimes called natural cyclodextrins and their solubilities in water are at the lower end of the desirable range. Nevertheless they proved very good solubilizing agents for some of the water insoluble molecules. To increase the aqueous solubilities of these natural cyclodextrins, molecular modifications of these a-, β-,γ- and
8- cyclodextrins have been carried out in the literature.
These modified cyclodextrins have much higher solubilities than their natural counterparts and they can be classified as Methylated derivatives of β-cyclodextrin, 2-hydroxypropylated β- and 7-cyclodextrins, sulfobutylated- β-cyclodextrins, branched cyclodextrins, acylated (3- and 7-cyclodextrins.
The cyclodextrins can be methylated by Kuhn-Trischmann methylation, Wacker"s industrial method with methyl chloride under pressure and Hakamori methylation using methylhalogenide and sodium hydride (see, Szente, L.; Szejtli, J.; Advanced Drug Delivery Reviews, (1996), 36, 17). The first two technologies have been used to produce randomly methylated cyclodextrin mixture. On the other hand Hakamori methylation is reported to produce a fixlly methylated heptakis 2,3,6-tri-O-methylated cyclodextrins. The introduction of methyl substituents in the place of the hydrogens of the hydroxy group of parent β-cyclodextrin dramatically improves the solubility of this randomly methylated cyclodextrin, referred in this invention as RAMEBCD versus the parent β-cyclodextrin.
There are totally 21 hydroxyl groups (14 secondary hydroxyl groups and seven primary hydroxyl groups) in β-cyclodextrin. The aqueous solubility of RAMEBCD increases as the number of methyl groups reaches around 13-14 and decreases as methylation approaches 21 methoxy groups per molecule of β-cyclodextrin. An example of a commercially available RAMEBCD product can be cited the one produced by Wacker Chemie and marketed under the name CAVASOL® W7 M Pharma (CAS no 128446-36-6). Aqueous solubilities of such RAMEBCDs are typically - 220g/100 ml of water. Such RAMEBCDs have an average degree of methylation -1.7 to 1.9 per anhydroglucose unit. Such RAMEBCDs are available commercially and have very good aqueous solubilities as noted. The general structure of such RAMEBCDs are shown as follows


Reacting cyclodextrins with propylene oxide in alkaline solution results in substitution of
the hydroxy groups in the cyclodextrins with 2-hydroxypropyl derivatives. A higher
substitution of the hydroxyls with propylene oxide also results in the formation of
oligomeric hydroxypropylene oxide side chain formation. Such 2-hydroxy-propyl-j3-
cyclodextrin referred in this invention as HPBCD is represented by the following generic
structure. Such materials are available commercially.

I
L

A review on the applications of cyclodextrin in the ophthalmic field has appeared (Loflssona, T.; Jarvinen, T.; Advanced Drug Delivery Reviews, (1999), 36, 59 ). A patent, US 6,346,273 describes the aqueous solubilization of forskolin through the use of polyvinylpyrrolidone and a surfactant, polyethyleneglycol-glyceryl tririicinoleate. The maximum solubility of Forskolin achieved in this patent is 0.2 %.

us Patent 4476140 describes a composition and method for treatment of Glaucoma by administration of a therapeutically effective amount of a material selected from the group consisting of forskolin, colforsin and polyoxygenated Labdane derivatives. The active agent concentration of 0.1 % to 4 % is reported herein to be physiologically effective when administered as a topical suspension to the eye.
US5070209, US4978678, US5023344, US4871764 describe novel 12-halogenated forskolin derivatives, intermediates and processes for the preparation thereof, and methods for reducing intraocular pressure utilizing compounds or compositions.
EP0268256 describes novel 12-halogenated forskolin derivatives, intermediates and processes for their preparation, and methods for reducing intraocular pressure utilizing the compounds or compositions.
As such, forskolin or its derivatives are sparingly soluble or almost insoluble in water. As a result, in the prior art, at best 0.01 % by weight of forskolin could be used in pharmaceutical preparations and compositions, which is inadequate for treatment of the condition (glaucoma).
Objects of the Invention
The main object of the invention is to provide a composition wherein the concentration of forskolin is upto 6 %.
Another object of the invention is to provide a method for solubilising forskolin and enhance its availability in pharmaceutical compositions.
Statement of the Invention:
The present invention relates to a solubilized diterpene based composition, said composition comprising forskolin ranging between 0.09% and 6% w/v and randomly-methylated p-cyclodextrins ranging between 5% and 70%, optionally along with excipients; a method for solubilising forskolin, said method comprising steps of: (a)

obtaining a clear solution by adding forskolin dissolved in an organic solvent ranging between 0.09% to 6% w/v in water containing randomly-methylated p-cyclodextrins ranging between 5 to 70% w/v; and (b) agitating the clear solution at room temperature for a period of 40-160 hrs followed by filtration to obtain the solubilised forskolin; and a method for solubilising forskolin, said method comprising the step of: obtaining a clear solution by adding forskolin ranging between 0.09% to 6% w/v in water containing randomly methylated p-cyclodextrin ranging between 5%-70% w/v.
Detailed Description
The present invention relates to a solubilized diterpene based composition, said composition comprising forskolin ranging between 0.09% and 6% w/v and randomly-methylated P-cyclodextrins ranging between 5% and 70%, optionally along with excipients.
In another embodiment of the present, the composition comprises forskolin and randomly-methylated p-cyclodextrin in the ratio of about 1:12.5.
In still another embodiment of the present invention, the excipients are selected from a group comprising of additives, viscosity enhancers, antioxidants, anti-obesity products, vasoirrigators, collagen boosters, anti-inflammatory agents and phosphodiesterase inhibitors.
In still another embodiment of the present invention, the additives are selected from a group comprising benzethonium chloride, chlorobutanol, methyl paraben, propyl paraben and thimerosal.
In still another embodiment of the present invention, the concentration of additive is ranging between 0.001 to 0.02 %.
In still another embodiment of the present invention, the viscosity enhancers are selected from a group comprising polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethyl cellulose.
In still another embodiment of the present invention, the concentration of viscosity enhancer is ranging between 0.1 to 2.0%.
In still another embodiment of the present invention, the anti-obesity products are selected from a group comprising hydroxycitric acid, garcinol and their respective salts.

In still another embodiment of the present invention, the antioxidants are selected from a
group comprising disodium salt of EDTA, sodium bisulfite, sodium metabisulfite,
thiourea, parabens, BHA, BHT, Vitamin E, ascorbates, green tea extract, rosmarinic acid
and curcuminoids.
In still another embodiment of the present invention, the concentration of antioxidant is
ranging between 0.1-1.0%.
In still another embodiment of the present invention, the composition is formulated into
dosage forms like capsule, tablet, injectable, patch, ointment, gel, emulsion, cream,
lotion, dentrifice, spray, drop or other dosage form including sustained release forms.
The present invention also relates to a method for solubilising forskolin, said method comprising steps of:
a) obtaining a clear solution by adding forskolin dissolved in an organic solvent ranging between 0.09% to 6% w/v in water containing randomly-methylated P-cyclodextrins ranging between 5 to 70% w/v; and
b) agitating the clear solution at room temperature for a period of 40-160 hrs followed by filtration to obtain the solubilised forskolin.
The present invention also relates to a method for solubilising forskolin, said method comprising the step of: obtaining a clear solution by adding forskolin ranging between 0.09% to 6% w/v in water containing randomly methylated p-cyclodextrin ranging between 5%-70% w/v.
In still another embodiment of the present invention, the ratio of forskolin and randomly-methylated P-cyclodextrin is 1:12.5.
In still another embodiment of the present invention, the organic solvent is selected from a group comprising ethanol, acetone and ethyl acetate.


Pharmaceutical compostions may be prepared employing the forskolin of the invention. The composition may comprise forskolin, its derivatives or analogues in combination with cyclodextrin and other additives, antioxidants and viscosity enhancers. Preferably, the amount of forskolin in the composition may be 0.09 to 6%. The amount of cyclodextrin may be about 5 to 70% by weight. The additives may include benzethonium chloride, chlorobutanol, methyl paraben, propyl paraben and thimerosal in an amount of 0.001 to 0.02 %. The antioxidant may be sodium bisulfite, sodium metabisulfite and thiourea in an amount of 0.1 to 1 %. The composition may also contain a viscosity enhancer such as polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethyl cellulose in an amount of 0.1 to 2 %.

The composition may be formulated as capsule, tablet, food product, injectable, patch, ointment, gel, emulsion, cream, lotion, dentrifice, spray, drop or other dosage form including sustained release forms, for human or veterinary use.
In another aspect, the invention provides a method for solubilising forskolin comprising the step of contacting forskolin with a cyclodextrin in the presence of a solvent and separating and obtaining the solubilised forskolin in a known manner. The forskolin used may be obtained from natural sources or synthetic. As above, the forskolin would include its isomers, derivatives and analogues.
Any commercially available cyclodextrin such as a-, β-, γ-cyclodextrins as well as their derivatized products such as RAMEBCD, HPBCD, HPGCD may be employed to solubilize Forskolin. The amount of cyclodextrin employed may be about 5 to 70 % by weight. The solvent employed in the said method is selected from water, ethanol, acetone or ethyl acetate. Preferably, to solubilize Forskolin using cyclodextrins, the chosen cyclodextrin and Forskolin are mixed in the solvent in a specific proportion. The solution is filtered to remove any undissoved particles and a clear solution of Forskolin is obtained.
The solvent upon removal leaves behind a white powder. Such powder is found to freely dissolve in water. If desired, additives, anti oxidants and viscosity enhancers may be added to the forskolin solution to prepare pharmaceutical compositions.
The inventors have found that by virtue of the above process the amount of forskolin that may be obtained in the final composition may be upto 6 %, which is far greater than the compositions taught by the prior art. The commercially available Ophthalmic preparation (like Timolol) used for reducing intraocular pressure are of synthetic nature and is often irritating to the eye. An advantage of the invention is that the Forskolin Ophthalmic solution prepared according to the process of the invention is obtained from a naturally occurring product and does not cause any eye irritation, and is thus superior to prior art products.

The additives that may be added to the solution of Forskolin are usually those used for maintaining sterility, pH maintenance, maintenance of osmolarity etc, A wide variety of choice exists in the selection of such additives. While benzalkonium chloride is used in the illustrative example for preservative, one could equally choose from many others such as Benzethonium chloride, chlorobutanol, methyl paraben, propyl paraben, Thimerosal etc.
An antioxidant such as the disodium salt of EDTA is used to stabilize the preparation; other antioxidants such as sodium bisulfite, sodium metabisulfite, thiourea could be used also among others. The other antioxidants that may be used may be of synthetic origin, such as parabens, BHA, BHT, Vitamin E, Ascorbates or Natural products such as Green Tea extract, Rosmarinic acid, Curcuminoids. The amount of the antioxidant used may be 0.1 to 0.5 % w/w in the formulation.
Especially for ophthalmic solutions, viscosity desired for an ophthalmic solution is in the range 25 and 50 cps. Viscosity enhancers such as polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, hydroxypropylmethyl cellulose, hydroxyethyl cellulose could be used.
In another aspect, the invention provides a method of using of forskolin composition for treatment of glaucoma, the composition being obtained by contacting forskolin with cyclodextrin in the presence of a solvent. The amount of forskolin used in the composition may vary from 0.09 % to 6 %.
The invention also provides a method of use of the formulation of the invention alone or in combination with polyvinyl pyrrolidone, hyaluronic acid and derivatives, in animals or human subjects presenting with dry eye syndrome
Preferably in the composition of the invention water soluble molecular and receptor probes for research and commercial purposes may be employed. Advantageously, the

composition provides health benefits of diterpenes such as forskolin, its analogs, congeners and derivatives, in humans and animals. The composition may be administered by topical, percutaneous, intravenous, sublingual or oral route.
Yet another advantage is that the composition of the invention is delivered as a formulation of Forskolin and related diterpenes as diet drinks for management of obesity, weight management and improving lean body mass, hypertension, allergy among the known applications of forskolin.
The composition of the invention is also useful as emulsions, sprays, solutions or aerosols, or cosmeceutical applications such as collagen boosting activity, anti-wrinkle properties, cellulite control, melanocyte modulator.
Further, the composition of the invention could be used in combination with antioxidants, lipase inhibitors, other anti-obesity products including hydroxycitric acid, garcinol, and their salts, vasoirrigators, other known collagen boosters, anti-inflammatory agents, phosphodiesterase inhibitors, among others.
The composition of the present invention is synergistic in nature in that it exhibits surprising result when forskolin is solubilied in cyclodextrin. The composition of the invention is therefore not a mere admixture.
The examples that are described below serve their purpose only as illustrative examples and do not limit in any way the broad scope of this invention.
ILLUSTRATIVE EXAMPLES
EXAMPLE 1: Determination of the aqueous solubility of Forskolin. Forskolin (300mg) was dried at 105°C for 6 hours. Dried Forskolin 200mg was stirred with 100ml water for 48 hours for the determination of intrinsic solubility at ambient temperature .Resulting solution was filtered through 0.45 µm nylon filter and analyzed for

the content of Forskolin by HPLC. Content of Forskolin by HPLC O.Olmg/ml or 0.001 % w/v; In other words Forskolin has a solubility of'--0.001 % w/v in water.
EXAMPLE 2: Forskolin (98 % assay, 25 mg) was added to 1ml water containing in the dissolved state 500mg hydroxypropyl β cyclodextrin, HPBCD, (-50 %) Suspension was agitated at 75 RPM in an isothermal shaker for 60 hours at temperature '-'30°C. Resulting solution was filtered through 0.45µm nylon filter and analyzed for the content of Forskolin by HPLC 1.33mg/ml or 0.133 % w/v.
EXAMPLE 3: Forskolin (98 % assay, 50 mg) was added to 1ml water containing 500mg Hydroxy propyl γ- cyclodextrin in the dissolved state. (HPGCD) (-50 %). Suspension was agitated at 75 RPM in an isothermal shaker for 60 hours at temperature -30°C. Resulting solution was filtered through 0.45µm nylon filter and analyzed for the content of Forskolin by HPLC 1.52mg/ml or 0.152 % w/v.
EXAMPLE 4: Experiments were performed by "changing the crystallinity of Forskolin by recrystallizing from methylene chloride and from ethyl acetate. Resulting "amorphous" Forskolin was used for complexation with Hydroxyropyl γ-cyclodextrin HPGCD. Forskolin (29.3 mg) recrystallized with methylene dichloride (Forskolin assay 99 %) was added to 3ml water containing 1.5gram Hydroxy propyl y-cyclodextrin, HPGCD (--50 %). Suspension was agitated at 75 RPM in an isothermal shaker for 160 hour at temperature 30°C. Resulting solution was filtered through 0.45µm nylon filter and analyzed for the content of Forskolin by HPLC 1.74mg/ml or 0.174 % w/v.
EXAMPLE 5: Forskolin (30.3 mg) recrystallized with ethyl acetate (Forskolin assay 98.8 %) was added to 3ml water containing 1.5gram Hydroxy propyl γ-cyclodextrin, HPGCD (-50 %). Suspension was agitated at 75 RPM in an isothermal shaker for 160 hour at temperature 30°C. Resulting solution was filtered through 0.45|im nylon filter and analyzed for the content of Forskolin by HPLC 3.38mg/ml or 0.338 % w/v.

EXAMPLE 6: Forskolin (98 % assay, 330mg) was added to 10ml water containing 4g of RAMEBCD (--40 %). Suspension was agitated at 75 RPM in an isothermal shaker for 40 hours at temperature 30°C. Resulting solution was filtered through 0.45µm nylon filter and analyzed for the content of Forskolin by HPLC 20.46mg/ml or 2.046 % w/v.

EXAMPLE 8: A typical aqueous formulation of Forskolin with a cyclodextrin is prepared as follows, RAMEBCD, being used as the example of cyclodextrin RAMEBCD (100 g) is taken in a one liter flask with mechanical or magnetic stirring facility. Forskolin (5.5 g) was charged into the flask. Water (400 ml) is charged to the flask and the contents were agitated at room temperature. A clear solution is obtained. If any

undissolved Forskolin particles are seen, they are resuspended and stirred. Benzalkonium chloride (50 mg) and Disodium EDTA (500 mg) are added and dissolved in the flask. The pH of the contents could be adjusted to the desired range with the help of O.IN sodium hydroxide, (usually pH range 3.5 to 7.5). Calculated amount of sodium chloride solution is added to maintain the osmolarity of the solution equivalent to that of 0.9 % sodium chloride. The total volume of the solution is made up to 500 ml after sterile filtration. A solution thus prepared has approximately 1 % of Forskolin in the dissolved state. Other cyclodextrins also could be used and depending on the cyclodextrin used, the dissolved content of Forskolin in water differed.
EXAMPLE 9: Forskolin (50 mg) was dissolved in 5ml acetone, and Igram of RAMEBCD was dissolved in 5ml acetone separately. Both the solutions were mixed together and solvent acetone was evaporated under reduced pressure. Residue was dried and dissolved in 5ml water. This residue dissolved very easily within 1 hour of stirring forming a clear colorless solution.
EXAMPLE 10: Isoforskolin also could be used in place of Forskolin. In one preparation, Isoforskolin (50 mg) was suspended in water containing a suitable amount of a cyclodextrin, for example, RAMEBCD (20g) in about 100 ml water. After agitation at room temperature, the solution was filtered and the resulting solution was analyzed by HPLC which showed the presence of Isoforkolin approximately 0.5 %; The amount of dissolved Isoforskolin could be altered by changing the amount of RAMEBCD.
EXAMPLE 11: An illustrative example of the biological activity of the preparation is presented. The anti-glaucoma activity of the forskolin composition was studied in albino rabbits. A 1 % solution of Forskolin in water as described in example 8 was used for the experiments
Study design:

Animal model: Albino rabbit
Number of groups: 4
Number of animals in each group: 6 in treatment group and 2 in control group
Materials and methods: Six albino rabbits of New Zealand strain, of both sexes, weighing 1.0-1.5 lb were chosen. The rabbits were housed in clean and well-ventilated open space. Each rabbit was fed with standard diet daily and water was administered ad libitum throughout the study.
Ocular hypertension was induced by the method reported by Bonomi et al (Invest Ophthalmol. 1976 Sep;15(9):781-4.) The rabbits were given 0.3 ml subconjunctival injection of Betnesol containing betamethasone sodium 4mg/ml, every day to each eye for a period of three weeks (the Intraocular pressure (lOP) at third week was maximum as per literature). Local anesthetic propracaine eye drops were used prior to subconjunctival injections.
In each rabbit the left eye was kept as control for glaucoma and the right eye was treated for glaucoma using Forskolin, Timolol, and the placebo.
For each treatment, the lOP readings were measured at intervals of 30 minutes up to 210 minutes using the non-contact tonometer (NCT).
Results


Statistical Analysis: The lOP readings of the placebo, Forskolin and Timolol were subjected to ANOVA (one way). The probability value (p value) was 0.0022 which is very significant, indicating that the variation in column means is not by chance.
The lOP readings of the placebo and forskolin were subjected to "t" test to determine whether the medians of Forskolin and the placebo differ significantly. The p value was found to be 0.0177 which is considered significant. Similarly, the lOP readings of the placebo and Timolol had a "p" value of 0.0087, which is again significant.
The lOP readings of Forskolin and Timolol were also subjected to "t" test. The p value was found to be 0.3999, which is not considered significant., implying that the activity of forskolin preparation is not significantly different from Timolol,
Conclusion: The Forskolin composition has anti-glaucoma activity comparable to Timolol.
EXAMPLE 12 (Preparation of a capsule): Forskolin 98 % (25 mg) was first formulated to a free flowing powder using maltodextrin or a mixture of magnesium

carbonate / dicalcium phosphate (225 mg) as carriers. The resulting powder containing 10 % forskolin was granulated in an RMG (Rapid Mixer Granulator). The granules were filled in soft gel capsules of size # 1.
EXAMPLE 13 (Preparation of a Tablet): Forskolin powder as prepared in example 12 can be made into tablet of desired size and shape using filler materials if required. The required dissolution / disintegration / tablet hardness / Mability can be achieved by using pharmaceutically acceptable binders, coating aids etc.
EXAMPLE 14 (Preparation of a gel): 1 % of forskolin 98 % was made soluble in a suitable hydrophilic solvent intended for semi solids. A clear gel base was made using desired range of carbopols, in which 1 % is the polymer, 1 % is preservatives and the rest is water. Into the clear gel base, forskolin 98 % solution was added with slow and constant stirring for a uniform, non aerated gel matrix.
EXAMPLE 15 (Preparation of an emulsion): 1 % of forskolin 98 % was made soluble in a suitable hydrophilic / lipophilic solvent intended for semi solids.
An oil phase was made with moderate heating up to 82°C with stearic acid, glyceryl stearates, cetyl Easters, palmitates and myristates as carriers. Emollients and penetration enhancers consisting of 8 to 10 % of the total 100 % emulsion was also made.
An aqueous phase was made with moderate heating up to 80°C with 1 % carbopol, 1 % hydrophilic castor oil glycols, about 1 % preservatives, 2 % glycerin and the rest is made of water.
Under constant heating and stirring the oil phase was added into aqueous phase till an uniform emulsion was made. At 50°c the forskolin solution was added into the emulsion base, with a suitable perfume if desired.
EXAMPLE 16 (Preparation of a cream): 1 % of forskolin 98 % was made soluble in a suitable hydrophilic / lipophilic solvent intended for semi solids.

An oil phase was made with moderate heating up to 82°C with spermaceti wax, fruit butters, stearic acid, glyceryl stearates, cetyl casters, palmitates , myristates and paraffins as carriers, emollients and penetration enhancers consisting of 10 to 15 % of the total
100% cream.
An aqueous phase was made with moderate heating upto 80°c with 1.5 % carbopol, 2 % hydrophilic castor oil glycols, maximum 1 % preservatives, 3 % glycerin and the rest is
water.
Under constant heating and stirring the oil phase was added into aqueous phase till an uniform cream is made. At 50°C the forskolin solution was added into the cream base with a suitable perfume if desired.
EXAMPLE 17 (Preparation of a spray): 1 % of forskolin 98 % was made soluble in a suitable solvent.
A carrier base was made using 1 % propylene / butylenes / di propylene glycol, 40 % alcohol (if the spray is an alcohol based spray) and the rest is water up to 99 %. If the spray is non alcoholic, 40 % alcohol can be substituted with water.
The forskolin solution added is into the spray base and then the final solution is ready to be filled in desired pump spray container.
EXAMPLE 18 (Preparation of an aerosol): 1 % of forskolin 98 % was made soluble in a suitable solvent may be in 5 % Iso Propyl Alcohol of the total 100 % aerosol.
The carrier base along with forskolin solution was put into an aerosol container. After being properly crimped, required carrier gas was filled up to 100 % of the aerosol.

EXAMPLE 19 (Preparation of a dentrifice): 1 % forskolin , 2 % clove powder, 1.5 % mint flavor, and rest calcium carbonate to 100 % mixed and pulverized together to form a dentrifice.
EXAMPLE 20 (Preparation of an ointment): 1 % of forskolin 98 % was made soluble in a suitable hydrophilic/lipophilic solvent intended for semi solids
An oil phase was made with moderate heating upto 82°C with paraffins, stearic acid, glyceryl stearates, cetyl casters, palmitates and myristates as carriers, emollients and penetration enhancers consisting of 18 to 25 % of the total 100 % ointment.
An aqueous phase was made with moderate heating upto 80°C with 1 % carbopol, 2 % hydrophilic castor oil glycols, maximum 1 % preservatives, 2 % glycerin and the rest is water.
Under constant heating and stirring the oil phase was added into aqueous phase till an uniform ointment is made. At 50°C the forskolin solution was added into the emulsion base with a suitable perfume if desired.









We claim:
1. A solubilized diterpene based composition, said composition comprising forskolin ranging between 0.09% and 6% w/v and randomly-methylated β-cyclodextrins ranging between 5% and 70%, optionally along with excipients.
2. The composition as claimed in claim 1, wherein the composition comprises forskolin and randomly-methylated β-cyclodextrin in the ratio of about 1:12.5.
3. The composition as claimed in claim 1, wherein the excipients are selected from a group comprising of additives, viscosity enhancers, antioxidants, anti-obesity products, vasoirrigators, collagen boosters, anti-inflammatory agents and phosphodiesterase inhibitors.
4. The composition as claimed in claim 3, wherein the additives are selected from a group comprising benzethonium chloride, chlorobutanol, methyl paraben, propyl paraben and thimerosal.
5. The composition as claimed in claim 4, wherein the concentration of additive is ranging between 0.001 to 0.02 %.
6. The composition as claimed in claim 3, wherein the viscosity enhancers are selected from a group comprising polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethyl cellulose.
7. The composition as claimed in claim 6, wherein the concentration of viscosity enhancer is ranging between 0.1 to 2.0%.
8. The composition as claimed in claim 3, wherein the anti-obesity products are selected from a group comprising hydroxycitric acid, garcinol and their respective salts.

9. The composition as claimed in claim 3, wherein the antioxidants are selected from a group comprising disodium salt of EDTA, sodium bisulfite, sodium metabisulfite, thiourea, parabens, BHA, BHT, Vitamin E, ascorbates, green tea extract, rosmarinic acid and curcuminoids.
10. The composition as claimed in claim 9, wherein the concentration of antioxidant is ranging between 0.1-1.0%.
11. The composition as claimed in claim 1, wherein the composition is formulated into dosage forms like capsule, tablet, injectable, patch, ointment, gel, emulsion, cream, lotion, dentrifice, spray, drop or other dosage form including sustained release forms.
12. A method for solubilising forskolin, said method comprising steps of:

a) obtaining a clear solution by adding forskolin dissolved in an organic solvent ranging between 0.09% to 6% w/v in water containing randomly-methylated p-cyclodextrins ranging between 5 to 70% w/v; and
b) agitating the clear solution at room temperature for a period of 40-160 hrs followed by filtration to obtain the solubilised forskolin.
13. A method for solubilising forskolin, said method comprising the step of:
obtaining a clear solution by adding forskolin ranging between 0.09% to 6% w/v
in water containing randomly methylated P-cyclodextrin ranging between 5%-
70% w/v.
14. The method as claimed in claim 12, wherein the ratio of forskolin and randomly-methylated p-cyclodextrin is 1:12.5.
15. The method as claimed in claim 12, wherein the organic solvent is selected from a group comprising ethanol, acetone and ethyl acetate.

16. The solubilised diterpene based composition and the method of solubilising forskolin as herein described with reference to foregoing examples.


Documents:

148-che-2005 claims.pdf

148-che-2005 correspondence others.pdf

148-CHE-2005 CORRESPONDENCE-OTHERS 19-10-2009.pdf

148-che-2005 form-1.pdf

148-che-2005-abstract.pdf

148-che-2005-claims.pdf

148-che-2005-correspondnece-others.pdf

148-che-2005-description(complete).pdf

148-che-2005-form 1.pdf

148-che-2005-form 26.pdf

148-che-2005-form 3.pdf

148-che-2005-form 5.pdf

148-che-2005-other documents.pdf

148-che-2005-pct.pdf

EXAMINATION REPORT REPLY.PDF


Patent Number 245785
Indian Patent Application Number 148/CHE/2005
PG Journal Number 05/2011
Publication Date 04-Feb-2011
Grant Date 01-Feb-2011
Date of Filing 22-Feb-2005
Name of Patentee SAMI LABS LTD
Applicant Address 19/1, IMAIN, II PHASE, PEENYA INDUSTRIAL AREA, BANGALORE-560 058
Inventors:
# Inventor's Name Inventor's Address
1 MAJEED, MUHAMMED 19/1, IMAIN, II PHASE, PEENYA INDUSTRIAL AREA, BANGALORE-560 058
2 BAMMI, RAJKUMAR 19/1, IMAIN, II PHASE, PEENYA INDUSTRIAL AREA, BANGALORE-560 058
3 NATARAJAN, SANKARAN 19/1, IMAIN, II PHASE, PEENYA INDUSTRIAL AREA, BANGALORE-560 058
PCT International Classification Number C07D 311/92
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA