HU217117B - Process for producing oktreotide pamoate - Google Patents

Abstract

The present invention relates to a process for the preparation of a novel salt of the prodrug, which is extremely stable in a physiologically floating or high-capacity polymeric matrix, and can be used as a sustained release formulation for sustained release. The composition can be used, inter alia, in cancer therapy. ŕ

Description

The present invention relates to a process for the preparation of a new salt of octreotide, octreotide pamoate. Octreotide pamoate, as a matrix, provides a sustained release of the active substance in a biodegradable or biocompatible polymer, e.g.

EP 23 031 discloses a number of somatostatin octapeptides and their salts, including octreotide derivatives, their salts and their therapeutic effect.

Embonic acid (pamoic acid) is also known (see Merck Index, 11th Edition, 1989, 6955).

Pharmaceuticals containing peptides are often poorly bioavailable in the blood when administered orally or parenterally, for example due to their metabolic instability. In addition, absorption through the mucous membrane is often poor with oral or nasal administration. When applied, it is difficult to achieve therapeutically effective blood levels over an extended period of time.

Parenteral administration of peptide agents in the form of a depot formulation in a biodegradable polymer, such as a microparticle or implant, allows sustained release of the peptide agent from a polymer that protects it from the enzymatic and hydrolytic action of the biological medium.

Known parenteral depot formulations containing the peptide active ingredient in a polymer in the form of microparticles or implants have, in very few cases, a satisfactory peptide release profile. Specific measures should be taken to achieve the sustained release of the peptide necessary to provide a therapeutically active agent blood level and, if desired, to avoid an excessive concentration of the active agent in the serum, resulting in unwanted pharmacological side effects.

The release pattern of the peptide drug depends on a number of factors, including, for example, the type of peptide, such as whether the peptide is in free form or otherwise, such as salt, which affects its water solubility. Another important factor is the choice of the polymer from a wide range of possible polymers, as described in the literature.

To date, no sustained-release octreotide formulation for parenteral administration has been placed on the market, perhaps due to the failure to produce a formulation with a satisfactory serum level profile.

*

a) (D) Phe-Cys-Phe- (D) Trp (generic name: octreotide) *

b) (D) Phe-Cys-Tyr- (D) Trp *

c) (D) Phe-Cys-Tyr- (D) Trp

The realization of such a formulation required the provision of a stable octreotide derivative providing a stable, satisfactory plasma level of the active ingredient, in a biodegradable or biocompatible matrix, while meeting other polymer requirements.

We have discovered that a new salt of octreotide, the pamoate salt, is extremely stable in such formulations.

Accordingly, the present invention relates to the preparation of octreotide pamoate by reacting octreotide or a salt thereof with an embryonic acid or a reactive derivative thereof.

The method of the invention allows the person in need of parenteral treatment with octreotide pamoate, for example, using the depot formulations described above. Particular emphasis is given to the treatment of acromegaly and breast cancer.

Octreotide is a compound of the somatostatin analogs.

Somatostatin is a tetradecapeptide of the following formula:

Ala-Gly-Cys-Lys-Asn-Phe-Phe-Trp

I I

Cys-Ser-Thr-Phe-Thr-Lys

This hormone is produced by the hypothalamus and other organs, such as the gastrointestinal tract, and is mediated with GRF, see neuroregulation of pituitary growth hormone release. In addition to inhibiting the release of growth hormone from the pituitary gland, somatostatin is effective in inhibiting many systems including the central and peripheral nervous system, the gastrointestinal tract and the smooth muscle of blood vessels. It also inhibits the release of insulin and glucagon.

The term "somatostatin" also includes analogues and derivatives thereof. Derivatives and analogs include straight chain, bridged, or cyclic polypeptides in which one or more amino acid units are omitted and / or substituted by one or more other amino acid residues and / or one or more functional groups are replaced by one or more other functional groups, and / or one or more groups are replaced by one or more other isosteric groups. In general, the above designation covers any modified derivative of a biologically active peptide that has a qualitatively similar effect to the unmodified somatostatin peptide.

Thus, somatostatin agonist analogues are useful for replacing natural somatostatin in its effects on the regulation of physiological functions. Preferred known somatostatins include:

* s-Thr-Cys-Thr-ol *

s-Va1-Cys-ThrNH ₂ * s-Val-Cys-Tr pNH ₂

HU217 117 Β * *

d) (D) Trp-Cys-Phe- (D) Trρ-Lys-Thr-Cys-ThrNH ₂ * *

e) (D) Phe-Cys-Phe- (D) Trp-Lys-Thr-Cys-ThrNH ₂ * *

f) 3- (2-Naphthyl) - (D) Ala-Cys-Tyr- (D) Trp-Lys-Val-Cys-Th r NH ₂ *

g) (D) Phe-Cys-Tyr- (D) Trp-Lys-Va 1 -Cys-β-Na 1 -NH ₂ * *

h) 3- (2-naphthyl) -Ala-Cys-Tyr- (D) Trp-Lys-Val-Cys ^ _-Nal-NH2 *

i) (D) Phe-Cys-β-Na 1 - (D) Trp-Lys-Va 1 -Cys-Thr-NH ₂ wherein in each of compounds a) -i) there is a bridge between the amino acids marked with *.

According to the invention, the pamoate salt is prepared in a manner conventional for salt formation, e.g. The reaction may be carried out in a polar solvent, for example at room temperature.

Formulations containing the compound of the invention may be used in the form of depot formulations, such as injectable microspheres or implants.

The compositions may be administered by conventional means, for example, by subcutaneous or intramuscular injection, according to a known indication for the active ingredient in the composition.

Prolonged release formulations containing the octreotide pamoate active ingredient may be administered for any indication known to the octreotide or derivative thereof, for example, as described in U.S. Patent No. 2199,829 A, and for acromegaly and breast cancer.

The microparticles produced according to the invention have a diameter of from 1 to 250 μ, preferably from 10 to 200 μ, especially from 10 to 130 μ, for example from 10 to 90 μ. Implants may be, for example, 1 to 10 mm ^{3 in} size. The amount of active ingredient, i.e. the amount of peptide present in the composition, depends on the desired daily release dose and thus on the rate of biodegradation of the encapsulating polymer. The exact amount of peptide can be determined by bioavailability assays. The compositions have a peptide content of at least 0.2% by weight, preferably 0.5-20% by weight, more preferably 2.0-10% by weight, particularly preferably 3.0-6% by weight, based on the polymer matrix.

The release time of the peptide from the microparticle ranges from 1-2 weeks to 2 months.

Preferably, the extended release formulation comprises somatostatin, such as octreotide, in a biodegradable, biocompatible polymeric vehicle which, when administered subcutaneously to a rat at a dose of 10 mg / kg body weight, produces at least 0.3 ng / ml, preferably less than 20 ng / ml levels are preferably maintained for 60 days.

Alternatively, the extended release formulation contains somatostatin, e.g. concentration up to 20 ng / ml.

Further advantageous properties of somatostatin-containing depot formulations, such as octreotide, depend on the production process:

Phase separation procedure

Rabbit 5 mg somatostatin / kg, intramuscular retention (0-42 days) 76% mean plasma level (cp, ideal) (0-42 days) 4 ng / ml

AUC (0-42 days) was 170 ng / ml χ days

Spray drying process

Rat, 10 mg somatostatin / kg, subcutaneous retention (0-42 days) Mean plasma level (cp, ideal) (0-42 days)

AUC (0-42 days)> 75%

4-6 ng / ml 170-210 ng / ml χ day

Rabbit, 5 mg somatostatin / kg, intramuscular retention (0-43 days)> 75% mean plasma level (cp, ideal) (0-43 days)

AUC (0-43 days)

Triple emulsion process

Rat, 10 mg somatostatin / kg, subcutaneous

4-6 ng / ml 200-240 ng / ml χ day (0-42 days)> 75%

4-6.5 ng / ml 170-230 ng / ml χ day retention mean plasma level (cp, ideal) (0-42 days)

AUC (0-42 days)

Rabbit, 5 mg somatostatin / kg, intramuscular retention (0-42 / 43 days)> 74% mean plasma level (cp, ideal) (0-42 / 43 days) 3.5-6.5 ng / ml AUC (0- 42/43 days) 160-270 ng / ml χ days

The octreotide pamoate-containing compositions of the present invention have the following properties:

1. the retention is at least 70%, preferably at least 74%, for example at least 75%, 80%, 88% or at least 89% over a period of 0 to 42 or 43 days, and / or

2, mean plasma levels (C _p ideal) 2.5-6.5 ng / ml, preferably from 4 to 6.5 ng / ml of a 0-42 day period into the rat somatostatin 10 mg when administered subcutaneously, and / or average plasma levels

HU217 117 Β

3.5-6.5, for example 4-6.5 ng / ml, for a period of 0-42 or days in saliva, when 5 mg of somatostatin is administered intramuscularly, and / or

3. the AUC for a period of 0-42 days is at least 160 ng / ml χ days, preferably 170-230 ng / ml χ days, in rats given 10 mg somatostatin subcutaneously, and / or 0-42 or For a period of 43 days, at least 160 ng / ml χ days, preferably 180-275 ng / ml χ days, for example 200-275 ng / ml χ days, for intramuscular administration of 5 mg somatostatin.

For quantitative characterization of sustained release formulations as described above, F. Nimmerfall and J. Rosenthaler, Intem. J. Pharmaceut. 32, 1-6 (1986)].

In short, the essence of the AD method is to calculate the spatial deviation of the experimental plasma profile from the ideal plasma profile, where the ideal profile is a constant average plasma level (C _p ideal)> obtained by subtracting the area under the experimental plasma level time curve (AUC). into a rectangle with the same area. From the percentage area difference (based on AUC), the percentage retention is calculated as follows:

% withholding = 100 χ (1 - AD / AUC)

In this procedure, the total measured plasma profile of a predetermined period is characterized by a single numerical index.

Proc. Natl. Acad. Sci. USA 85: 5688-5692 (1988). 4 * illustrates the * *

Plasma level profile of the somatostatin analogue octapeptide D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH _{2 in} rats.

However, no clear comparison can be made between the above profile and the rat profile of the preparation according to the invention, since the plasma level profile is based on another administration method (intramuscular injection) and, more importantly, the active substance content of the microcapsules (2-6%). label is inaccurate (microcapsule portions 25-50 mg for 30 days, but determination for at least 45 days). Furthermore, the poly (D1-lactide-co-glycolide) used is not precisely described.

Thus, the communication value of the above communication is too low to be considered as a prepublication contrary to the invention.

The invention will now be illustrated by the following examples.

The molecular weight (M _w ) of the polymers is the average molecular weight determined by GLPC using a polystyrene standard.

Example 1

Preparation of octreotide pamoate

Dissolve 10.19 g (10 mmol) of octreotide free base and 3.88 g (10 mmol) of embryonic acid in 1 liter of 1: 1 water-dioxane. The mixture is filtered and lyophilized. Octreotide pamoate hydrate was obtained as a yellow powder.

[a] ² ° D = + 7.5 ° (c = 0.35, DMF)

Factor = 1.4, where Factor means: weight of lyophilisate / weight of octreotide present.

The pamoate salt is used as a matrix in a polymer as described in U.S. Patent No. 2,265,331 and Hungarian Patent Application No. 211,602, which provides excellent stability.

Example 2 g of poly (D, L-lactide-co-glycolide) glucose _(Mw = 45,000, molar ratio of 55/45, prepared as described in B No. 2145422, U.K. patent specification, a polydispersity of about 1.7, prepared from 0.2% glucose) Dissolve in 25 ml of ethyl acetate with stirring with a magnetic stirrer, then add 75 mg of octreotide in 3 ml of methanol. 25 ml of silicone oil (Dow 360 Medical Fluid, 1000 cs) was added to the polymer-peptide mixture. The resulting mixture was added to a mixed emulsion containing 400 mL of heptane, 100 mL of pH 4 phosphate buffer, 40 mL of Dow 360 Medical Fluid, 350 and 2 mL of Span 80 (emulsifier). Stirring is continued for at least 10 minutes. The resulting microparticles were recovered by vacuum filtration and dried overnight in a vacuum oven. At least 80% of the resulting microparticles fall within the size range of 10-40 μ.

The microparticles were suspended in vehicle and administered intramuscularly at a dose of 4 mg octreotide to white New Zealand rabbits. Blood samples are periodically collected from rabbits, with plasma levels measured from RIA at 0.5-2 ng / ml for 21 days.

Example 3 Preparation of poly (D, L-lactide-co-glycolide) glucose (50:50 molar ratio, _{w w} = 46000) as described in British Patent 2145422 B, polydispersity about 1.7: 0.2% (prepared from glucose) was dissolved in 10 mL of methylene chloride with magnetic stirring and then 75 mg of octreotide dissolved in 0.133 mL of methanol was added. The mixture is stirred vigorously, for example, at 20,000 rpm for 1 minute in an Ultra-Turax device to obtain very small octreotide crystals suspended in the polymer solution.

The suspension is sprayed at high speed (Niro atomizer) and the small droplets are dried under a stream of warm air to obtain microparticles. The microparticles were collected in a "cyclone" and dried overnight in a vacuum oven at room temperature.

The microparticles were washed with 1/15 mol / L acetate pH 4.0 for 5 minutes and then dried again in a vacuum oven at room temperature. After 72 hours, the microparticles are sieved to a fine product (0.125 mm particle size).

The microparticles were suspended in vehicle and administered intramuscularly at 5 mg / kg octreotide to white rabbits (Chinchilla mice) and 10 mg / kg subcutaneously to male rats. From time to time, blood samples are taken from the animals; blood samples from rabbits (5 mg

HU217 117 Β dose) 0.3-10.0 ng / ml, rat 0.5-7.0 ng / ml for 42 days.

Example 4

As described in Example 3, microparticles were prepared by spray drying, except that octreotide was suspended directly in the polymer solution without methanol.

The resulting microparticles were suspended in vehicle and administered at a dose of 10 mg octreotide / kg subcutaneously to male rats. Blood samples are taken periodically and the plasma levels measured from the samples are 0.5-10.0 ng / ml for 42 days.

Example 5 g of poly (D, L-lactide-co-glycolide) glucose _(Mw = 46,000, molar ratio 50:50, prepared as described in B No. 2145422, U.K. Patent manner a polydispersity of about 1.7, prepared from 0.2% glucose) Dissolve in 2.5 ml of methylene chloride and add 75 mg of octreotide in 0.125 ml of deionized water. The mixture is vigorously stirred with an Ultra-Turax for 1 minute at 20,000 rpm (internal v / o phase).

Gelatin A is dissolved in 200 ml deionized water at 50 ° C and then cooled to 20 ° C (outer phase v). The v / o and v phases are mixed vigorously. Thus, the inner v / o phase is separated into small droplets which are dispersed homogeneously in the outer v / o phase. The resulting triple emulsion was stirred slowly for 1 hour. The methylene chloride is then evaporated and the microcapsules are hardened from small droplets of the inner phase. After the microparticles have settled, the supernatant is aspirated off, the microparticles are recovered by vacuum filtration and rinsed with water to remove the gelatin. After drying, sieving, washing and re-drying, which were carried out as described in Example 4, the microparticles were obtained.

The microparticles were suspended in vehicle and administered intramuscularly at 5 mg / kg octreotide to white rabbits (Chinchilla) and 10 mg / kg subcutaneously to male rats. Animals are periodically sampled; plasma levels as measured by RIA (rabbit 85 mg dose) are 0.3-15 ng / ml for 42 days in rats and 0.5-8.0 ng / ml.

Claims (6)

PATIENT INDIVIDUAL POINTS A process for the preparation of octreotide pamoate, wherein the octreotide or salt thereof is reacted with embonic acid or a reactive derivative thereof. 2. The method of claim 1, wherein the octreotide is reacted with embonic acid. Process according to claim 1 or 2, characterized in that the reaction is carried out in a polar solvent. 4. Referring to 1-3. Process according to any one of claims 1 to 3, characterized in that the reaction is carried out in a mixture of water and dioxane. 5. Process according to any one of claims 1 to 3, characterized in that the reaction is carried out at room temperature. 6. Process according to any one of claims 1 to 3, characterized in that the product obtained is lyophilized.