Title of Invention

CHEMICALLY STABLE COMPOSITIONS OF 4- HYDROXY TAMOXIFEN

Abstract A class of chemically stable 4-hydroxy tamoxifen compositions is characterized by roughly equal amounts of the Z-4-hydroxy tamoxifen and E-4-hydroxy tamoxifen isomers, such that the potency of the compositions is not affected adversely by the isomerization that occurs between these two forms. The inventive compositions are useful for preventing or for treating medical conditions.
Full Text Background of the Invention
The present invention relates to chemically stable isomeric compositions of 4-
hydroxy tamoxifen (4-OHT), an active metabolite of the drug tamoxifen.
Tamoxifen acts on estrogen receptors throughout the body and, as both an
agonist and antagonist, provokes a wide range of systemic effects. It is widely
prescribed for breast cancer because it blocks the effects of estrogen in breast tissue,
thereby slowing or stopping the growth of cancer cells that are already present and
preventing the development of new cancers. Because of its wide ranging effects,
tamoxifen causes significant side effects, which increase the risk of endometrial cancer,
endometrial hyperplasia and polyps, deep vein thrombosis and pulmonary embolism,
changes in liver enzyme levels, and ocular toxicities, including cataracts. Additionally,
patients treated with tamoxifen report having hot flashes, vaginal discharge, depression,
amenorrhea, and nausea.
Due to tamoxifen's drawbacks, some cancer researchers have proposed
substituting 4-hydroxy tamoxifen as a treatment for breast cancer. 4-Hydroxy tamoxifen
acts as a selective estrogen receptor modulator (SERM) that exhibits tissue-specificity
for estrogen receptive tissues. In breast tissue, it functions as an estrogen antagonist.
Studies have shown that 4-hydroxy tamoxifen can regulate the transcriptional activity of
estrogen-related receptors, which may contribute to its tissue-specific activity. In vitro,
4-hydroxy tamoxifen exhibits more potency than tamoxifen, as measured by binding
affinity to estrogen receptors, or ERs, and a binding affinity similar to estradiol for
estrogen receptors (Robertson et al, 1982; Kuiper et al, 1997).
Research data supports the use of 4-hydroxy tamoxifen for treating breast
cancer. In in vitro studies, 4-hydroxy tamoxifen inhibits the growth of both normal and
cancerous breast cells (Nomura, 1985; Malet, 1988, 2002; Charlier, 1995). Additionally,
transdermally delivered 4-hydroxy tamoxifen exhibits an anti-tumor effect on human
breast tumors grown subcutaneously in mice (U.S. patent No. 5,904,930). In humans,
limited experiments have shown that percutaneously administered 4-hydroxy tamoxifen


can concentrate in local breast tumors, with very little systemic distribution (Mauvais-
Jarvis, 1986). 4-Hydroxy tamoxifen also shows promise for treating mastalgia,
excessive scarring and gynecomastia, and for decreasing breast density.
In the chemical structure of 4-hydroxy tamoxifen, or 1-[4-(2-N-
dimethylaminoethoxy)phenyl]-1-(4-hydroxyphenyl)-2-phenylbut-1-ene, a double bond
between two carbon atoms gives rise to two stereoisomeric forms. Unlike tamoxifen, 4-
hydroxy tamoxifen does not possess two identical phenyl groups, but rather has four
different groups distributed over the alkene group. Cis-trans terminology, therefore, can
not properly be applied to the isomers of 4-hydroxy tamoxifen. Instead, E from the
German Entgegen, meaning across, and Z from the German Zusammen, meaning
together, are properly applied (see figures 1 and 2). Both isomers of 4-hydroxy
tamoxifen are biologically active, but the Z isomer is more active biologically than the E
isomer (U.S. Patent 6,172,263).
In.the solid state, an isomeric mixture of 4-hydroxy tamoxifen is very stable. In
solution, however, isomerization between the Z and E forms occurs. Malet et al.

observed that spontaneous isomerization of Z- into E-4-hydroxy tamoxifen occurred
within 24-48h, but stabilized rapidly at a Z/E ratio of 70/30, whether in stock solution,
culture medium or cultured cells and regardless of temperature (-20°C, 4°C or 37°C).
See Malet et al. (2002). Katzenellenbogen et al. further demonstrated that hydroxy
tamoxifen isomers that are initially 99% pure undergo a time- and temperature-
dependent isomerization, so that after 2 days in tissue culture medium at 37°C they have
isomerized to the extent of 20%. This isomerization occurs more slowly at 4°C than at
37°C and its speed can be reduced by various antioxidants. See Katzenellenbogen et al.
(1985). According to Sigma, a supplier of 4-hydroxy tamoxifen, the 4- hydroxy
tamoxifen E-Z interconversion process is favored by solvents of low dielectric constants
when exposed to light and when incubated in culture medium.
The isomerization process potentially can affect the activity of a pharmaceutical
composition comprising 4-hydroxy tamoxifen as an active ingredient. To meet
international pharmaceutical regulatory requirements, therefore, a need exists for
chemically stable compositions of 4-hydroxy tamoxifen. A "stable" pharmaceutical
composition is one whose qualitative and quantitative composition, including physical,
chemical and biological characteristics, do not significantly change during time under


specific conditions of temperature and moisture, e.g., during 3 years at 25°C/60%HR, 1
year at 30°C/65%HR and/or 6 months with 40°C/75%HR. "Significant change" refers
qualitative and/or quantitative differences that might affect the potency, efficacy or
safety of a pharmaceutical composition.
In providing a stable 4-hydroxy tamoxifen composition, it would be helpful to
have a more complete understanding of the 4-hydroxy tamoxifen isomerization process.
Summary of the Invention


The present inventors have discovered that the isomerization of 4-hydroxy
tamoxifen in solution equilibrates at a Z:E-isorner ratio of approximately 1:1. Moreover,
they have discovered that once this equilibrated ratio is attained, it remains stable.
In accord with this discovery, the present invention includes pharmaceutical
compositions having 4-hydroxy tamoxifen as an active agent, wherein approximately
50% of the 4-hydroxy tamoxifen exists in Z isomeric form and the remainder is in E
isomeric form. In specific embodiments, the pharmaceutical composition is formulated
for percutaneous administration in a gel, a solution or another pharmaceutical form
containing alcohol and an aqueous vehicle.
In a specific example, a gel formulation, the pharmaceutical compositions
comprise:
a) about 0.01 % to 0.20 % by weight of 4-hydroxy tamoxifen,
b) about 0.5 % to 2.0 % by weight of isopropyl myristate,
c) about 60% to 75% by weight of absolute alcohol,
d) about 25% to 40% by weight of aqueous vehicle,
e) about 0.5% to 5% by weight of gelling agent,
wherein the percentage of components are weight to weight of the composition.
In another aspect, the invention includes a method of treating or preventing
medical conditions by administering a pharmaceutical composition having 4-hydroxy
tamoxifen as an active agent, wherein approximately 50% of the 4-hydroxy tamoxifen
exists in Z isomeric form and the remainder is in E isomeric form, to a patient in need


thereof. Medical conditions for which such administration is useful include breast
cancer, mastalgia, breast density, excessive scarring and gynecomastia.
' For purposes of prophylaxis or treatment, the pharmaceutical compositions may
be administered by any means that delivers 4-hydroxy tamoxifen to estrogen receptor-
bearing cells in vivo. It is preferable that the administration be done percutaneously
(topically), to avoid the first-pass effect and related liver metabolism of the 4-hydroxy
tamoxifen. For percutaneous administration, 4-hydroxy tamoxifen may be applied to any
skin surface. Application to the breasts is advantageous because 4-hydroxy'tamoxifen
tends to concentrate in local subcutaneous tissues with estrogen receptors when
administered percutaneously.
A broad range of topical formulations are suitable for performing the invention,
but hydroalcoholic solutions and hydroalcoholic gels are preferred. The concentration of
4-hydroxy tamoxifen in these formulations may vary, but a dose should result in local 4-
hydroxy tamoxifen tissue concentrations that effectively oppose estrogenic driven
effects.
In another aspect, the present invention includes a kit for storage that comprises
(a) a pharmaceutical composition having 4-hydroxy tamoxifen as an active agent,
wherein approximately 50% of the 4-hydroxy tamoxifen exists in Z isomeric form and
the remainder is in E isomeric form, and (b) a container, wherein the pharmaceutical
composition is contained within the container. In specific embodiments of this kit, the
container may be a unit dose packet or a multiple dose container, such as a container
with a metered pump.
In another aspect, the present invention relates to a method for making a
pharmaceutical composition comprising 4-hydroxy tamoxifen as an active agent, wherein
approximately 50% of the 4-hydroxy tamoxifen exists in Z isomeric form and the
remainder is in E isomeric form.
Brief Description of the Figures
Figure 1 illustrates the E and Z isomers of tamoxifen.
Figure 2 illustrates the reversible isomerism of 4-hydroxy tamoxifen.

Figure 3 illustrates the isomer concentration ratio (as a percentage) for Panchim
batch 98RD10079 at 25°C.
Figure 4 illustrates the isomer concentration ratio (as a percentage) for Panchim
batch 98RD10079 at 30°C.
... Figure 5 illustrates the isomer concentration ratio (as a percentage) for Panchim
batch 98RD10079 at 40°C.
Figure 6 illustrates the isomer concentration ratio (as a percentage) for ICI batch
Bx 17 at 40°C.
Figure 7 illustrates the isomer concentration ratio (as a percentage) for solutions
II-IV at 25°C.
Figure 8 illustrates the isomer concentration ratio (as a percentage) for solutions
II-IV at 30°C.
Figure 9 illustrates the isomer concentration ratio (as a percentage) for solutions
II-IV at 40°C.
Detailed Description of the Preferred Embodiments
The present invention is based on the very surprising discovery that the
isomerization of 4-hydroxy tamoxifen in solution equilibrates at a Z:E isomer ratio of
approximately 50:50, rather than the 70:30 ratio reported by Malet et al., and that once
this equilibrated ratio is attained, it remains stable. The inventors further discovered that
inter-conversion of the E and the Z isomers of 4-hydroxy tamoxifen (see Figure 2) is a
reversible reaction having an equilibrium constant k determined by the following
formula:

where [E] and [Z] are the equilibria concentrations of the corresponding isomers, and kf
and kr respectively are the forward and reverse rate constants. The rates for the forward
and reverse reactions, therefore, are equivalent.


These insights on the behavior of 4-hydroxy tamoxifen isomers make po ssible
the development of chemically stable pharmaceutical compositions that contain roughly
equal amounts of 4-hydroxy tamoxifen Z and E isomers. In such compositions, the
isomerization that occurs between Z and E forms does not significantly affect the
composition's potency, efficacy or safety.
Moreover, in view of the severity of pharmaceutical regulations, especially as to
shelf-life stability, it is required to provide products whose compositions do not evolve
with time. It is therefore a great advantage to provide formulations whose compositions
are stable, and thus reliably and precisely defined.
The skilled person would know how to determine the relative amounts of the E
and Z isomers in a given composition. For example, and as exemplified below, it is
possible to use HPLC techniques to estimate the Z/E ratio.
As discussed above, the prior art describes compositions with a Z/E ratio of
70/30. In addition, according to the art, the Z isomer is believed to have a higher
biological activity than its E counterpart. Therefore, taken together, the prior art
teachings seem to point towards compositions enriched in the Z isomer.
By contrast, the present invention provides compositions comprising 4-h.ydroxy
tamoxifen with a Z/E ratio of about 50/50, and methods for making such compositions.
This ratio is particularly suitable for administration to a human subject, since it
essentially corresponds to the in vitro physiological equilibrium ratio found in tissues
(Mauvais Jarvis P et al., Cancer Research, 1986,46, pl521-1525).
The inventors have performed several experiments to study the equilibration of
4-hydroxy tamoxifen isomers under different conditions of light, temperature, pH and
moisture, as well as in different media, at different concentrations of 4-hydroxy
tamoxifen and at different alcohol/aqueous vehicle ratios. In brief, they prepared
alcoholic solutions containing different concentrations of 4-hydroxy tamoxifen at
different ratios of Z and E isomers, then observed the isomerization that occurred in
those solutions over time at different temperatures and pH values (see the Examples
below). By 6 months, a stable ratio (approximately 1: 1) of Z and E isomers was attained
under many conditions, and a clear trend was observable under all conditions. The rate
of equilibration directly depended on temperature, pH, alcohol/aqueous vehicle content,

/


light and 4-hydroxy tamoxifen concentration. In all cases, only the rate of equilibration
was affected (see Examples below), but not the final ratio of Z and E isomers, which
surprisingly remained approximately 1:1.
From a chemical kinetics viewpoint, dielectric constant is recognized as one of
the fundamental properties that influences solvolytic reaction rates. In this regard,
publications exist that highlight the influence of water on the degradation of molecules.
For example, Sanyude et al, studied the influence of the water:alcohol ratio on the
degradation of aspartame. They reported that the degradation rate of aspartame
increased as the dielectric constant of the solvent medium decreased, i.e., when the water
concentration in the medium decreases. By contrast, the present inventors have found
that the isomerization rate of 4-hydroxy tamoxifen is increased as the dielectric constant
of the solvent medium is increased, i.e., when the water concentration in the medium
increases.
In accord with the inventors' discoveries, the present invention includes
pharmaceutical compositions that comprise 4-hydroxy tamoxifen, wherein about 50% of
the 4-hydroxy tamoxifen exists in a Z isomeric form and the remainder of the 4-hydroxy
tamoxifen exists in an E isomeric form. In specific embodiments, about 45% - 55%,
about 46% - 54%, about 47% -'53%, about 48% - 52%, about 49% - 51% or about 50% '
of the 4-hydroxy tamoxifen is in a Z isomeric form. Preferably about 49% - 51%, and
more preferably about 50% of the 4-hydroxy tamoxifen is in a Z isomeric form. These
contents are defined at the equilibrium state and not at the manufacture of the
pharmaceutical composition.
Equilibrated ratios of Z and E 4-hydroxy tamoxifen isomers can be obtained in
a pure alcoholic composition or a mixture of an alcohol and a aqueous vehicle by
admixing known quantities of the isomers or by subjecting the composition to conditions
that speed the equilibration process, such as high temperature, high 4-hydroxy tamoxifen
content, high aqueous vehicle content or UV light. The inventors have shown that the
molecular size of the alcohol (ethanol or isopropanol) does not have an effect on the rate
of isomerization.
Pharmaceutical compositions of the present invention may be formulated in any
dosage form capable of delivering 4-hydroxy tamoxifen to estrogen receptors in vivo.


Preferably, the compositions are formulated for "percutaneous administration," a phrase
that denotes any mode of delivering a drug from the surface of a patient's skin, through
the stratum comeum, epidermis, and dennis layers, and into the microcirculation. This is
typically accomplished by diffusion down a concentration gradient. The diffusion may
occur via intracellular penetration (through the cells), intercellular penetration (between
the cells), transappendageal penetration (through the hair follicles, sweat, and sebaceous
glands), or any combination of these.
Percutaneous administration of 4-hydroxy tamoxifen offers several advantages.
First, it avoids the hepatic metabolism that occurs subsequent to oral administration
(Mauvais-Jarvis et al., 1986). Second, percutaneous administration significantly reduces
systemic drug exposure, and the attendant risks from non-specifically activating estrogen
receptors throughout the body; this, because topical 4-hydroxy tamoxifen is absorbed
primarily into local tissues. In particular, when 4-hydroxy tamoxifen is percutaneously
applied to breasts, high concentrations accumulate in the breast tissue, presumably due to
many estrogen receptors therein, without creating a high plasma concentration (Mauvais-
Jarvis et al., supra).
The effectiveness of percutaneous drug administration depends on many
factors, including drug concentration, surface area of application, time and duration of
application, skin hydration, physiochemical properties of the dmg, and partitioning of the
dmg between the fonnulation and-the skin. Dmg formulations intended for percutaneous
use take advantage of these factors to achieve optimal delivery. Such formulations often
comprise penetration enhancers that improve percutaneous absorption by reducing the
resistance of the stratum comeum by reversibly altering its physiochemical properties,
changing hydration in the stratum comeum, acting as co-solvent, or changing the
organization of lipids and proteins in the intercellular spaces. Such enhancers of
percutaneous absorption include surfactants, DMSO, alcohol, acetone, propyleneglycol,
polyethylene glycol, fatty acids or fatty alcohols and their derivatives, hydroxyacids,
pyrrolidones, urea, essential oils, and mixtures thereof. In addition to chemical
enhancers, physical methods can increase percutaneous absorption. For example,
occlusive bandages induce hydration of the skin. Other physical methods include
iontophoresis and sonophoresis, which use electrical fields and high-frequency


ultrasound, respectively, to enhance absorption of drugs that are poorly absorbed due to
their size and ionic characteristics.
The many factors and methods relating to percutaneous drug delivery are
reviewed in REMINGTON: THE SCIENCE AND PRACTICE OF PHARMACY, Alfonso R.
Gennaro (Lippincott Williams & Wilkins, 2000), at pages 836-58, and in PERCUTANEOUS
ABSORPTION: DRUGS COSMETICS MECHANISMS METHODOLOGY, Bronaugh and Maibach
(Marcel Dekker, 1999). As these publications evidence, those in the pharmaceutical
field can manipulate the various factors and methods to achieve efficacious percutaneous
delivery.
For percutaneous administration, 4-hydroxy tamoxifen may be delivered in a
hydroalcoholic solution, hydroalcoholic gel, ointment, cream, gel, emulsion (lotion),
powder, oil or similar formulation.
In preferred embodiments of the invention, 4-hydroxy tamoxifen is formulated
in a alcoholic formulation, preferably in a hydroalcoholic gel. The amount of 4-hydroxy
tamoxifen in such a gel may range from about 0.001 to about 1.0 gram of 4-hydroxy
tamoxifen per 100 grams of gel. Preferably, it ranges from about 0.01 to about 0.2 gram
of 4-hydroxy tamoxifen per 100 grams of gel. In such embodiments, 4-hydroxy
tamoxifen may constitute about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%,
0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%,
0.19% or 0.20% by weight of the pharmaceutical composition.
4-Hydroxy tamoxifen formulations of the invention generally will comprise one
or more nonaqueous vehicles, such as alcoholic vehicles. These vehicles should be
capable of dissolving both 4-hydroxy tamoxifen and any penetration enhancer used.
They also should have a low boiling point, preferably less than 100oC at atmospheric
pressure, to permit rapid evaporation upon contact with the skin. Preferred alcoholic
vehicles are ethanol and isopropanol. In particular, ethanol effectively contributes to the
percutaneous absorption of 4-hydroxy tamoxifen by rapidly evaporating upon contact
with skin. The amount of absolute alcoholic vehicle in a formulation according to the
invention generally ranges between 35% and 99.9%, preferably between 50% and 85%,
more preferably between 60%) and 75% by weight. Thus, the amount of absolute


nonaqueous vehicle in a gel formulation may be about 60%, 61%, 62%, 63%, 64%, 65%,
66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74% or 75% by weight.
Formulations also may comprise an aqueous vehicle, which permits
solubilization of any hydrophilic molecules in a formulation, and also promotes
moisturization of the skin. An aqueous vehicle also can regulate pH, preferably in the
range of about 4 to about 12, more preferably in the range of about 6 to about 11, even
more preferably in the range of about 8 to about 10, and most preferably at about 9. As
shown below, the pH, and therefore the choice of a buffer solution, affects the rate of
equilibration between 4-hydroxy tamoxifen E and Z isomers. The final equilibrium ratio,
however, remains equal to about 1:1 regardless of the buffer.
Aqueous vehicles include alkalinizing and basic buffer solutions, including
phosphate buffered solutions (e.g., dibasic or monobasic sodium phosphate), citrate
buffered solutions (e.g., sodium citrate or potassium citrate) and simply purified water.
The phosphate buffer is preferred according to the invention. The amount of an aqueous
vehicle preferably ranges between 0.1 % and 65% by weight of the pharmaceutical
composition, more preferably between 15% and 50%, and still more preferably between
.25%.and 40%, Thus, the amount of an aqueous vehicle may be about 25%, 26%, 27%,
28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%. In the case
that formulations contain an aqueous vehicle, the amount of absolute alcoholic vehicle in
a formulation is preferably from about 60% to about 75%.
4-Hydroxy tamoxifen formulations may also comprise one or more
percutaneous absorption enhancers. The preferred percutaneous absorption enhancers
are fatty acid esters. One highly preferred example of a fatty acid ester penetration
enhancer is isopropyl myristate. When isopropyl myristate is used in a gel, the amount
may range from about 0.1 to about 5.0 grams per 100 grams of gel. Preferably, the
amount of isopropy myristate ranges from about 0.5 to about 2.0 grams per 100 grams of
gel. hi such embodiments, isopropyl myristate may constitute about 0.5%, 0.6%, 0.7%,
0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0% by
weight of the pharmaceutical composition.
Additionally, 4-hydroxy tamoxifen formulations may comprise one or more
gelling agents to increase the viscosity of a formulation and/or to function as a


solubilizing agent. Depending on the gelling agent's nature, it may constitute between
0.1% and 20% by weight of a formulation, preferably between 0.5% and 10%, more
preferably between 0.5% and 5%. Thus, the amount of a gelling agent may be about
0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% or 5.0%. Preferred gelling
agents include carbomers, cellulose derivatives, poloxamers and poloxamines. More
particularly, preferred gelling agents are chitosan, dextran, pectins, natural gum and
cellulose derivatives such as ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl
cellulose, hydroxypropyl methyl cellulose (HPMC), carboxymethyl cellulose (CMC),
and the like. One highly preferred gelling agent is hydroxypropyl cellulose.
When a formulation comprises a gelling agent, in particular a non-
preneutralized acrylic polymer, it may advantageously also comprise a neutralizing
agent. The neutralizing agent/gelling agent ratio preferably is between 10:1 and 0.1:1,
more preferably between 7:1 and 0.5:1, and still more preferably between 4:1 and 1:1.
Thus, the neutralizing agent/gelling agent ratio may be about 7:1, 6:1, 5:1, 4:1, 3:1, 2:1,
1:1 or 0.5:1. A neutralizing agent should form, in the presence of the polymer, salts that
are soluble in the vehicle. A neutralizing agent also should permit optimum swelling of
polymer chains during neutralization of charges and formation of polymer salts. Useful
neutralizing agents include sodium hydroxide, ammonium hydroxide, potassium
hydroxide, arginine, aminomethylpropanol, trolamine and tromethamine. Those skilled
in the art will select a neutralizing agent according to the type of gelling agent employed
in a formulation. When cellulose derivatives are used as gelling agents, however, no
neutralizing agents are required.
Table 1 describes the composition of two highly preferred 4-hydroxy tamoxifen
gel formulations. All the component are pharmaceutically acceptable components.


Pharmaceutical compositions of the invention may be administered to treat
numerous medical conditions for which tamoxifen and 4-hydroxy tamoxifen are useful.
For example, they may be administered to treat breast cancer (Mauvais-Jarvis, 1986;
Example 4), mastalgia (Fentiman 1986, 1988, 1989), excessive scarring (Hu, 1998; Hu
2002) or gynecomastia (Gruntmanis and Braunstein (2001)). They also may be
administered to prevent breast cancer in patients at high risk for developing that disease
or to reduce breast density when that condition interferes with mammography (Atkinson,
1999; Brisson, 2000; Son, 1999). See also U.S. provisional patent application Nos.
60/433,959, filed December 18, 2002; 60/433,958, filed December 18, 2002; and
60/458,963, filed April 1, 2003, each of which is incorporated herein by reference, for a
complete description of these uses.
Although the invention is not constrained to any particular theory, clinically
significant side effects of anti-estrogen agents occur when the agents displace estradiol in
non-target tissues. Because 4-hydroxy tamoxifen and estradiol have similar binding
affinities for estrogen receptors, a competition between them for receptor binding would
be approximately equal when the concentration of each compound approximates that of
the other. If the 4-hydroxy tamoxifen concentration exceeds the estradiol concentration,
the former will be bound preferentially to the estrogen receptors, and vice versa. By
administering 4-hydroxy tamoxifen locally, high concentrations can be achieved in the
target tissues without simultaneously raising 4-hydroxy tamoxifen plasma levels to a
point where significant systemic competition for estradiol receptors occurs.


In women, doses of 4-hydroxy tamoxifen that result in plasma concentrations
less than about 80 pg/mL, or the mean estradiol concentration in normal premenopausal
women, are preferred. More preferably, doses of 4-hydroxy tamoxifen will result in
plasma concentrations less than about 50 pg/mL. In men, doses of 4-hydroxy tamoxifen
that result in plasma concentrations less than about 20 pg/mL, or the meanestradiol
concentration in normal men, are preferred, The daily doses to be administered can
initially be estimated based upon the absorption coefficients of 4-hydroxy tamoxifen, the
breast tissue concentration that is desired, and the plasma concentration that should not
be exceeded. Of course, the initial dose may be optimized in each patient, depending on
individual responses.
When administering a percutaneous formulation for breast conditions, doses on
the order of 0.25-2.0 mg/breast/day of 4-hydroxy tamoxifen should achieve the desired
result, with doses of about 0.5-1.0 mg/breast/day being preferred. In particular
embodiments, the dosage is about 0.5, 0.75 or 1.0 mg/breast/day of 4-hydroxy
tamoxifen.
For the treatment of excessive scarring, doses on the order of 0.25 to 6 u.g of 4-
hydroxy tamoxifen/cm2/day should achieve the desired result, with doses of about 0.25
to 3 µg being preferred, and doses of 0.5 to 2.5 µg/cm 2/day being more preferred.
Doses of about 1.0 and 2.0 µg/cm2/day are highly preferred for treating scarring
conditions.
Pharmaceutical compositions of the invention may be packaged into kits for
storage. Such kits comprise (a) a pharmaceutical composition as described herein, and
(b) a container, wherein the pharmaceutical composition is contained within the
container. The container may be a unit dose packet, such as a foil packet, or a multiple
dose container, such as a container with a metered pump. Preferably, the container is
impervious to light.
In another aspect, the present invention relates to a method for making a
pharmaceutical composition comprising 4-hydroxy tamoxifen. In particular, there is
provided a method for making a pharmaceutical composition of the invention, as
described above.

In one embodiment, the present invention is directed to a method for making a
pharmaceutical composition, comprising the step of bringing a composition comprising
4-hydroxytamoxifen to an equilibrium state, wherein about 45%-55%, about 46%-54%,
about 47%-53%, about 48%-52%, about 49%-51% or about 50% of said 4-hydroxy
tamoxifen exists in a Z isomeric form and the remainder of said 4-hydroxy tamoxifen
exists in an E isomeric form.
In another embodiment, the present invention provides a method comprising the
steps of:
(i) providing a detennined amount of 4-hydroxy tamoxifen;
(ii) providing at least one excipient;
(iii) combining said 4-hydroxy tamoxifen and said at least one
excipient, thereby forming a pharmaceutical composition;
(iv) bringing said pharmaceutical composition to an equilibrium state,
wherein about 45%-55%, about 46%-54%, about 47%-53%, about
48%-52%, about 49%-51% or about 50% of said 4-hydroxy
tamoxifen exists in a Z isomeric form and the remainder of said 4-
hydroxy tamoxifen exists in an E isomeric form.
In one embodiment, said step (i) comprises providing a determined amount of
4-hydroxy tamoxifen in a Z isomeric form, and/or providing a determined amount of 4-
hydroxy tamoxifen in an E isomeric form. The 4-hydroxy tamoxifen can be provided
using various relative amounts of the E and Z isomers. For example, it is possible to
provide the 4-hydroxy tamoxifen in only one isomer (e.g. only E or only Z). It is also
possible to provide both isomers in equal or different amounts.
Excipients are known in the art. In one embodiment of the invention, said
excipient is selected from the group consisting of water, pharmaceutically acceptable
aqueous buffers, penetration enhancers, gelling agents, oils, neutralizing agents and
mixtures thereof. The various embodiments described above for the composition of the
invention (ingredients, amounts thereof...) can be transposed to the methods of the
invention. The skilled person would know how to proceed for providing the desired
ingredients in the desires quantities.


According to the invention, said method comprises the step of bringing said
pharmaceutical composition comprising 4-hydroxytamoxifen to an equilibrium state.
Said equilibrium state is generally a state wherein the ratio of the E/Z isomers does not
significantly vary with time, because said pharmaceutical composition has reached
equilibrium. In said equilibrium state, about 45%-55%, about 46%-54%, about 47%-
53%, about 48%-52%, about 49%-51% or about 50% of said 4-hydroxy tamoxifen exists
in a Z isomeric form and the remainder of said 4-hydroxy tamoxifen exists in an E
isomeric form.
The kinetics according to which the equilibrium is reached depend upon various
parameters, such as the initial E/Z ratio (i.e. the respective amounts of the Z and E
isomers initially provided), the final pH of the composition, the nature and respective
amounts of the ingredients of the composition, the dielectric constant of the composition,
the temperature of manufacture, the storage temperature, and the possible exposition to
light (duration, wavelength(s), ...)
The skilled person would know how to monitor the progress of the
isomerization, and adjust the parameters in order to ensure that the equilibrium state is
indeed reached.
Examples of parameters include:
- temperatures ranging 25-40°C, e.g. 30-35°C during the manufacture, and/or
- temperatures ranging 25-40°C, e.g. 30-35°C the storage, and/or
- storage of 0.5-6 months, e.g. 1, 2, 3, 4, 5, or 6 months, and/or
- exposure to light, especially UV light, during the manufacture, and/or
exposure to light, especially UV light, during the storage, and/or
final pH of the composition, and/or
dielectric constant of the composition, and/or
- ratio water/alcohol, e.g. ratio water/ethanol, in the composition, and/or
- initial E/Z ratio of 2/98, 60/40, 63/37, 70/30, 10/90, 0/100...
The method of the invention may also comprise the step of packaging said
pharmaceutical composition in a container, e.g. in a unit dose packet or in a multiple
dose container with a metered pump.

Reference to the following, illustrative examples will help to provide a more
complete understanding of the invention.
Example 1
This example demonstrates that isomerization of 4-hydroxy tamoxifen occurs
in solution and that the isomerization ultimately reaches an equilibrium at which about
50% of the 4-hydroxy tamoxifen exists in the Z isomeric form, with the remainder being
in the E isomeric form.
A. Preparation of Solutions Containing 4-Hydroxy tamoxifen
Hydroalcoholic solutions containing 4-hydroxy tamoxifen were prepared, based
on the following gel formula:

In the hydroalcoholic solutions, phosphate buffer was substituted for Klucel.
The composition of the buffer was as follows:

Solutions containing five different concentrations (0.02%, 0.04%, 0.06%,
0.08% and 0.10%) of 4-hydroxy tamoxifen were prepared. The composition of each
solution is shown in the table below.


At each of the stated concentrations, separate solutions containing Z-4-hydroxy
tamoxifen or a mixture of Z- and is-4-hydroxy tamoxifen were prepared. 4-hydroxy
tamoxifen from three separate manufacturers was tested:

Because only a small quantity of Z-4-hydroxy tamoxifen was available from
SIGMA, only a 0.06% solution of that batch was prepared. This solution was tested, as
described below, only at 25°C and 40°C.
B. Study Conditions
Each solution was subdivided into three parts in 30 ml brown glass bottles, then
placed in ovens regulated at 25°, 30°, and 40°C.
The relative amounts of Z- and E-4-hydroxy tamoxifen isomers were
determined at the initiation of the study and at 2-week, 1-month, 2-month, 3-month, 4-
month and 5-month time points.
C. Analytical Methods
HPLC was employed to determine the relative amounts of each 4-hydroxy
tamoxifen isomer, using a standard solution of 4 hydroxy tamoxifen as a reference.
Operating parameters for the HPLC were as follows:

For HPLC, the hydro alcoholic solutions were diluted in the mobile phase to
obtain a 4-hydroxy tamoxifen concentration close to 2.3 µg/ml.


The order of elution was as follows:
4-OHT E : retention time about 13.3 min
4-OHT Z : retention time about 15.0 min.
Percentages of each isomer were calculated using the following formulas:

D. Data fitting:
The reversible isomerization reaction and the equilibrium reaches are lied by
the following relationship :

where
A0 = initial concentration of the reagent
Aeq = concentration of the same reagent at equilibrium
A = the concentration of A at time t
kf = forward rate constant
kr = reverse rate constant
t = time measured in months


E. Results
The tables below show results for the study; by the 6-month time point, many
solutions had equilibrated at approximately a 1:1 ratio of Z and E isomers. The rate
constant of the isomer inter-conversion directly depended on both temperature, initial
concentration of the pure Z isomer and the initial concentration of the E/Z isomer
mixture.
The individual Z and E isomer content as a function of time are presented in
figures 3, 4 and 5 for 4-hydroxy tamoxifen over the concentration range of 0.02% to
0.1% total. 4-Hydroxy tamoxifen solution was stored at 25°C (figures 3), 30°C (figure
4) and 40°C (figure 5). The 4-hydroxy tamoxifen drug substance used to prepare the
solution had an initial concentration ratio for E and Z isomers of 63 % and 37 %,
respectively (PANCHIM batch 9SRD10079).
As the nominal 4-hydroxy tamoxifen was varied from 0.02% to 0.10%, the
magnitude of the rate constants for the reversible isomerism increased linearly. The
magnitude of the rate constants also increased with temperature.
The same equilibrium ratio at approximately a 1:1 was observed starting from a
4-hydroxy tamoxifen drug substance with an initial E/Z ratio of 2/98 (Batches
PANCHIM 7421 ) and 0/100 (batch ICI Bx 17) (see figure 6 for example). Batches
PANCHIM 7421 (E/Z ratio 2/98) and ICI Bx 17 (E/Z ratio 0/100) presented rate
constants that were very similar in magnitude for each nominal 4-hydroxy tamoxifen
concentration and at each temperature investigated. Surprisingly, the closer the initial
E/Z ratio is to 1:1, the higher the rate constant to reach the equilibrium is (see table 1).


Example 2:
This example demonstrates the effects of isopropyl myristate, the nature of the
alcohol present, and the alcohol/phosphate buffer ratio on the isomerization of 4-hydroxy
tamoxifen. It appears that the choice of a non-aqueous vehicle (buffer or water) does not
significantly affect the isomerization process. The amount of the non-aqueous vehicle is
indirectly proportional to the rate of isomerization, but the end Z/E equilibrium ratio was
unaffected by the amount of non-aqueous vehicle.

Solutions containing 0.06 % 4-hydroxy tamoxifen were prepared as described
in the table below :

Solutions II, III and IV described above were prepared with PANCHIM batch
98RD10079 of 4-hydroxy. tamoxifen. The initial E/Z ratio was 63%/37%.
Reference solution : Gel formulation without the gelling agent KLUCEL
Solution II: Reference solution without Isopropyl myristate and containing ethanol
Solution III : Solution II with the ethanol replaced by Isopropyl alcohol
Solution IV : Solution II with the ethanol/ buffer ratio of 50/50 instead of 66.5/33.5
As in Example 1, isomerization in each solution was tracked over time. The
figures below show results.
The effect of replacing ethanol by isopropyl alcohol and eliminating the
isopropyl myristate have no significant effect on the reversible kinetics of 4-hydroxy
tamoxifen.
Increasing the aqueous vehicle (buffer) concentration from 33.5% to 50%
greatly increases the rate constant at 25°C and 30°C. The difference is less pronounced
at 40°C. The increase in buffer concentration increase the electric constant of the
mixture and thus facilitates the polarization of the hydroxyl group and consequently the
conjugation of the double bond of the alkene group of 4-hydroxy tamoxifen. The same
phenomenon was observed replacing buffer with water. It is important to note also the
role of the pH of the buffer solution on the kinetics of 4-hydroxy tamoxifen reversible
isomerism.

Example 3:
This example demonstrates the effects of extreme temperature on 4-hydroxy
tamoxifen isomerization. Extremely high temperatures speed the equilibration process,
while extremely low temperatures slow it. This example also shows that the amount of
aqueous vehicle contained in the mixture affects the rate of isomerization, as noted in
Example 2.
Two solutions containing 0.06% Z-4-hydroxy tamoxifen were prepared:
solution V and solution VI. Solution V contained 4-hydroxy tamoxifen in pure ethanol
solution. Solution VI contained 4-hydroxy tamoxifen in a mixture of 66.3% water and
33.7% ethanol. The amount of isomerization that occurred in each solution was observed
after one week at -20 °C, 25 °C and 60 °C. The table below shows results. After one
week, no isomerization was observed at -20 °C and 25 °C, whereas a beginning of
isomerization was observable and 60 °C. In view of the results published by Malet et al.,
it was surprising that isomerization was not detectable in solutions V and VI after a week
of storage at -20°C and 25°C.





Example 5:
This example demonstrates the effects of pH on 4-hydroxy tamoxifen
isomerization. The amount of isomerization that occurred in solutions containing 0.06%
of 4-hydroxy tamoxifen with initial E/Z ratios of 100/0 or 37/63 was observed for two
months at 40°C. The 4-hydroxy tamoxifen was in a mixture of 66.5 % absolute ethanol,
32.4% of either phosphate (pH 2 to 8) or carbonate (pH 10) buffer, and 1% of isopropyl
myristate. Table 4, below, shows results.


Low and high pH speed the equilibration process. That is, the closer the pH is
to neutral (7.0), the slower equilibration occurs. The pH, however, does not appear
significantly to affect the equilibrium E/Z isomer ratio of roughly 1:1.
Example 6: Methods for making a pharmaceutical compositions of 4-
hydroxytamoxifen equilibrated to an E:Z isomer ratio of about 1:1
The following examples illustrate the methods of the invention. These methods
advantageously lead to stable compositions of 4-hydroxy tamoxifen having an E:Z
isomer ratio of about 1:1.
Method A:
(i) 0.06 g of 4-hydroxy tamoxifen containing both isomers E and Z at a
respective level of 60/40 is mixed with 66.5 g of absolute ethanol and stirred
until completely dissolved at room temperature;
(ii) 1.0 g of isopropyl myristate is then added and mixed;
(iii) 32.4 g of aqueous phosphate buffer is added and mixed to the solution (the
final pH is about 9);
(iv) Finally, the solution is transferred into an inactinic glass bottle and then
stored at 25°C/60% of relative humidity during 6 months.
Method B:
(i) 0.08 g of 4-hydroxy tamoxifen containing both isomers E and Z at a
respective level of 60/40 is mixed with 53.2 g of absolute ethanol and stirred
until completely dissolved at room temperature;
(ii) 0.8 g of isopropyl myristate is then added and mixed;
(iii) 25.9 g of aqueous phosphate buffer is added to the solution (to reach a final
PH of 9);
(iv) Finally, the solution is transferred into an inactinic glass bottle and then
stored at 40°C/75% of relative humidity during 2 months.

Method C:
(i) 0.08 g of 4-hydroxy tamoxifen containing both isomers E and Z at a
respective level of 0/100 is mixed with 53.2 g of absolute ethanol and stirred
at room temperature until complete dissolution;
(ii) 0.8 g of isopropyl myristate is then added and mixed;
(iii) 25.9 g of aqueous phosphate buffer is added to the solution (to reach a final
pH of 9);
(iv) Finally, the solution is incorporated in a inactinic glass bottle and then stored
at 40°C/75% of relative humidity during 6 months.
Method D:
(i) 0.06 g of 4-hydroxy tamoxifen containing both isomers E and Z at a
respective level of 60/40 is mixed with 66.5 g of absolute ethanol and stirred
until complete dissolution at room temperature;
(ii) 32.4 g of aqueous carbonate buffer is added and mixed to the solution (the
final pH is of 12);
(iii) Finally, the solution is transferred into an inactinic glass bottle and then
stored at 40°C during 15 days.

Cited Publications
Each of the following publication is incorporated here, in its entirety, by
reference.
Atkinson, C, R. Warren, S.A. Bingham, and N.E. Day, Mammographic patterns as a
predictive biomarker of breast cancer risk: effect of tamoxifen, Cancer Epidemiology,
Biomarkers & Prevention, 8: 863-66 (1999).
Brisson, J., B. Brisson, G. Cote, E. Maunsell, S. Bembe, and J. Robert, Tamoxifen and
mammographic breast densities, Cancer Epidemiology, Biomarkers & Prevention, 9:
911-15(2000).
Bronaugh and Maibach, Percutaneous Absorption: Drugs Cosmetics Mechanisms
Methodology, Marcel Dekker 1999.
Charlier, C, A. Chariot, N. Antoine, M.P. Merville, J. Gielen, V. Castronovo, Tamoxifen
and its active metabolite inhibit growth of estrogen receptor-negative MDA-MB-435
cells, 49(3): 351-8 (1995).
Fentiman, I.S., Tamoxifen and mastalgia. An emerging indication, Drugs 32: 477-80
(1986).
Fentiman, I.S., M. Caleffi, H. Hamed, and M.A. Chaudary, Dosage and duration of
tamoxifen treatment for mastalgia: a controlled trial, British Journal of Surgery 75: 845-
46(1988).
Fentiman, I.S., M. Caleffi, H. Hamed, and M.A. Chaudary, Studies of tamoxifen in
women with mastalgia, British Journal of Clinical Practice, Supplement 68, 43(11): 34-
36(1989)).
Gruntmanis, U. and G.D. Braunstein, Treatment of gynecomastia, Curr. Opin. Investig.
Drugs, 2:643-649 (2001).
Hu, D., M.A. Hughes, G.W. Cherry, Topical tamoxifen—a potential therapeutic regimen
in treating excessive dermal scarring?, Br. J. Plast. Surg., 50(6): 462-9 (1998).

Hu, D., X. Zhu, M. Xu, B. Chen, A.H. Margaret, W.C. George, The inhibitory effect of
tamoxifen on human dermal fibroblast-populated collagen lattices, Zhonghua Zheng
Xing Wai Ke Za Zhi, (18(3): 160-2 (2002).
Katzenellenbogen, J.A., K.E. Carlson, B.S. Katzenellenbogen, Facile geometric
isomerization of phenolic non-steroidal estrogens and antiestrogens: limitations to the
interpretation of experiments characterizing the activity of individual isomers, J. Steroid
Biochem,.22(5): 589-96 (1985).
Kuiper, G.G.J.M., B. Carlsson, K. Grandien, E. Enmark, J. Heggblad, S. Nilsson, J.
Gustafsson, Comparison of the ligand binding specificity and transcript tissue
distribution of estrogen receptors a and (3, Endocrinology, 138:863-870 (1997).
Malet C, A. Compel, P. Spritzer, N Bricourt, NH Yaneva, I. Mowszowicz, F. Kutten
and P Mauvais Jarvis, Tamoxifen and hydroxytamoxifen isomers versus estradiol effects
on normal human breast cells in culture, Cancer Research, 48: 7193-7199 (1988).
Malet, C, P. Spritzer, C. Cumins, D. Guillaumin, P. Mauvais-Jarvis, F. Kuttenn, Effect
of 4-hydroxytamoxifen isomers on growth and ultrastructural aspects of normal human
breast epithelial (HBE) cells in culture, J. Steroid Biochem. & Mol. Bio., 82: 289-96
(2002).
Mauvais-Jarvis, P., N. Baudot, D. Castaigne, P. Banzet, and F. Kuttenn, Trans-4-
hydroxytamoxifen concentration and metabolism after local percutaneous administration
to human breast, Cancer Research, 46:1521-1525 (1986).
Nomura, Y., H. Tashiro, F. Takaeko, Effects of antiestrogens and medroxyprogesterone
acetate on the clonogenic growth of tamoxifen-sensitive and resistant human breast
cancer cells, Jpn. J. Cancer Chemotherapy, 12(4): 844-50 (1985).
Remington: The Science and Practice of Pharmacy, Alfonso R. Gennaro, Lippincott
Williams & Wilkins, 2000, pp. 836-858.
Robertson and Katzenellenbogen, J. Org. Chem., 47: 2387 (1982).
Robertson, D.W., J.A. Katzenellenbogen, D.J. Long, E.A. Rorke and B.S.
Katzenellenbogen, Tamoxifen antiestrogens. A comparison of the activity,

pharmacokinetics, and metabolic activation of the cis and trans isomers of tamoxifen, J.
Steroid Biochemistry, 16(1):1-13 (1982).
Son, H.J., and K.K. Oh, Significance of follow-up mammography in estimating the effect
of tamoxifen in breast cancer patients who have undergone surgery, American Journal of
Roentgenology, 173: 905-909 (1999).
U.S. patent No. 5,904,930
U.S. patent No. 6,172,263
U.S. patent application No. 60/433,958
U.S. patent application No. 60/433,959
U.S. patent application No. 60/458,963

We claim:
1. Method for making a stable hydroalcoholic pharmaceutical composition, comprising the
steps of:
(i) providing a determined amount of 4-hydroxy tamoxifen, wherein 47%-53%
or 50% of said 4-hydroxy tamoxifen exists in a Z isomeric form and the
remainder of said 4-hydroxy tamoxifen exists in an E isomeric form;
(ii) providing an alcohol capable of dissolving 4-hydroxytamoxifen;
(iii) providing an aqueous vehicle including alkalinizing and basic buffers and
optionally a penetration enhancer selected from a fatty acid ester;
(iv) combining said 4-hydroxy tamoxifen and said alcohol and said aqueous
vehicle and said optional penetration enhancer, thereby forming a
pharmaceutical composition which is at equilibrium state.

2. The method as claimed in claim 1, wherein said pharmaceutical composition at the .
equilibrium state comprises 48%-52% or 49%-51 % of said 4- hydroxy tamoxifen in a Z
isomeric form and the remainder of said 4-hydroxy tamoxifen in an E isomeric form.
3. The method as claimed in claim 1, wherein said pharmaceutical composition is for
percutaneous administration.
4. The method as claimed in claim 1, further comprising adding gelling agents, oils,
neutralizing agents and mixtures thereof.
5. The method as claimed in claim 1, wherein said pharmaceutical composition is selected
from the group consisting of hydroalcoholic gels, hydroalcoholic solutions, ointments,
creams, or emulsions (lotions).
6. The method of claim 5, wherein said hydroalcoholic gel comprises ethyl alcohol,
isopropyl myristate, and hydroxypropylcellulose.

7. The method as claimed in claim 4, comprising adding:
a) 0.001 % to 1% by weight of 4-hydroxy Tamoxifen;
b) 0.5 % to 2% by weight of isopropyl myristate;
c) 60% to 75% by weight of absolute alcohol;
d) 25% to 40% by weight of aqueous vehicle;
e) 0.5% to 5% by weight of gelling agent;
wherein the sum of the above components a) to e) is 100% by weight.
8. The method as claimed in claim 7, wherein the 4-hydroxy tamoxifen constitutes 0.01%,
0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%,
0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19% or 0.20% by weight of the
composition.
9. The method as claimed in claim 7, wherein the isopropyl myristate constitutes 0.5%,
0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%
or 2.0% by weight of the composition.
10. The method as claimed in claim 7, wherein the alcohol is ethanol or isopropanol, and
constitutes 60 to 75% by weight of the composition.
11. The method as claimed in claim 7, wherein the aqueous vehicle is a phosphate buffered
solution, and constitutes 25% to 40% by weight of the composition.
12. The method as claimed in claim 7, wherein the aqueous vehicle is a phosphate buffered
solution, and the pH of said pharmaceutical composition is 4 to 12, 6 to 11, 8 to 10, or 9.
13. The method as claimed in claim 7, wherein the gelling agent is a polyacrylic acid,
hydroxypropylcellulose or other cellulose derivative, and constitutes 0.5% to 5% by
weight of the composition.

14. The method as claimed in claim 7, further comprising adding a neutralizing agent
selected from the group consisting of sodium hydroxide, ammonium hydroxide,
potassium hydroxide, arginine, aminomethylpropanol and tromethamine, which
neutralizing agent exists at a neutralizing agent/gelling agent ratio between 4:1 and 1:1.
15. A stable pharmaceutical hydroalcoholic composition at the equilibrium state comprising:
a) 0.001 to 1% by weight of 4-hydroxy tamoxifen, wherein 47%-53% or
50% of said 4-hydroxy tamoxifen exists in a Z isomeric form and the remainder
of said 4-hydroxy tamoxifen exists in an E isomeric form
b) 35 to 99.9 % by weight of an alcohol capable of dissolving 4-
hydroxytamoxifen;

c) 0.1 to 65% by weight of aqueous vehicle including alkalinizing and basic
buffers; and
d) Optionally 0.1 to 5% by weight of penetration enhancer selected from
fatty acid esters.

16. The pharmaceutical composition as claimed in claim 15, wherein 48%-52% or 49%-51%
of said 4- hydroxy tamoxifen exists in a Z isomeric form and the remainder of said 4-
hydroxy tamoxifen exists in an E isomeric form.
17. The pharmaceutical composition as claimed in claim 15, which is made for percutaneous
administration.
18. The pharmaceutical composition as claimed in claim 15, which further comprises gelling
agents, oils, neutralizing agents and mixtures thereof.
19. The pharmaceutical composition as claimed in claim 17, wherein said 4-hydroxy
tamoxifen is formulated in a hydroalcoholic gel, a hydroalcoholic solution, an ointment, a
cream, or an emulsion (lotion).

20.The pharmaceutical composition as claimed in claim 19, wherein said hydroalcoholic gel
comprises ethyl alcohol, isopropyl myristate, and hydroxypropylcellulose.
21. The pharmaceutical composition as claimed in claim 18, wherein said pharmaceutical
composition comprises:
a) 0.001 % to 1 % by weight of 4-hydroxy tamoxifen;
b) 0.5 % to 2 % by weight of isopropyl myristate;
c) 60% to 75% by weight of absolute alcohol;
d) 25% to 40% by weight of aqueous vehicle;
e) 0.5%) to 5% by weight of gelling agent;
wherein the sum of the above components a) to e) is 100% by weight.
22. The pharmaceutical composition as claimed in claim 21, wherein the 4-hydroxy
tamoxifen constitutes 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%,
0.09%, 0.10%, 0.11 %, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19% or
0.20% by weight of the composition.
23. The pharmaceutical composition as claimed in claim 21, wherein the isopropyl myristate
constitutes 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%,
1.7%, 1.8%, 1.9%) or 2.0% by weight of the composition.
24. The pharmaceutical composition as claimed in claim 21, wherein the alcohol is ethanol or
isopropanol, and constitutes 60 to 75% by weight of the composition.
25. The pharmaceutical composition as claimed in claim 21, wherein the aqueous vehicle is a
phosphate buffered solution, and constitutes 25% to 40% by weight of the composition.
26. The pharmaceutical composition as claimed in claim 21, wherein the aqueous vehicle is a
phosphate buffered solution, and the pH of said pharmaceutical composition is 4 to 12, 6
to 11, 8 to 10, or 9.

27. The pharmaceutical composition as claimed in claim 21, wherein the gelling agent
is a polyacrylic acid, hydroxypropylcellulose or other cellulose derivative, and
constitutes 0.5% to 5% by weight of the composition.
28. The pharmaceutical composition as claimed in claim 21, which further comprises
a neutralizing agent selected in the group consisting of sodium hydroxide,
ammonium hydroxide, potassium hydroxide, arginine, aminomethylpropanol and
tromethamine, which neutralizing agent exists at a neutralizing agent/gelling
agent ratio between 4:1 and 1:1.


A class of chemically stable 4-hydroxy tamoxifen compositions is characterized
by roughly equal amounts of the Z-4-hydroxy tamoxifen and E-4-hydroxy
tamoxifen isomers, such that the potency of the compositions is not affected
adversely by the isomerization that occurs between these two forms. The
inventive compositions are useful for preventing or for treating medical
conditions.

Documents:

02453-kolnp-2006 abstract.pdf

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02453-kolnp-2006 description(complete).pdf

02453-kolnp-2006 drawings.pdf

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2453-KOLNP-2006-FORM 1 1.1.pdf

2453-KOLNP-2006-FORM 13.pdf

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2453-KOLNP-2006-FORM 26.1.pdf

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2453-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf


Patent Number 251984
Indian Patent Application Number 2453/KOLNP/2006
PG Journal Number 16/2012
Publication Date 20-Apr-2012
Grant Date 19-Apr-2012
Date of Filing 29-Aug-2006
Name of Patentee LABORATOIRES BESINES INTERNATIONAL
Applicant Address 3 RUE DU BOURG I' ABBE, 75003 PARIS, FRANCE
Inventors:
# Inventor's Name Inventor's Address
1 DANA, HILT 39 FLAGGY MEADOW ROAD GORHAM MAINE 04038, USA
2 BRIGITTE TARAVELLA 73 QUAI PANHARD ET LEVASSOR, 75013 PARIS, FRANCE
3 RICHARD FEDYNEC LA MARLOTTERIE, ROUTE DE SONCHAMP, CLAIREFONTAINE, FRANCE
4 VALERIE MASINI-ETEVE 18 RUE DES GRANDS CHENES, 91370 VERRIERES LE BUISSON, FRANCE
PCT International Classification Number A61K 31/138
PCT International Application Number PCT/EP2005/003455
PCT International Filing date 2005-03-18
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 US 10/805 530 2004-03-22 U.S.A.
2 04290762.6 2004-03-22 U.S.A.