SI9400087A - Novel process for the preparation of cetrorelix lyophilisate - Google Patents

Abstract

Sterile freeze-dried cetrorelix acetate (a peptide described in EP299402) is used in the treatment of female infertility. Independent claims are also included for the following: (1) use of sterile freeze-dried cetrorelix acetate for protecting gonads against noxious agents that damage germ cells, e.g. radiation treatment and chemotherapy; (2) a composition comprising sterile freeze-dried cetrorelix acetate and optionally excipients for use in the treatment of female infertility; (3) a composition comprising sterile freeze-dried cetrorelix acetate and optionally excipients for protecting gonads against noxious agents that damage germ cells, e.g. radiation treatment and chemotherapy with cytostatic agents.

Description

-1New Procedure for Manufacturing CETRORELIX Lyophilizates

Cetrorelix is a decapeptide with the final acid amide group used as the acetate salt. The synthesis and certain pharmacological effects are described in EP application 299 402.

The active substance should be administered subcutaneously at a dose of 0.1 to 20 mg. Aqueous decapeptide solutions are unstable; autoclaving in the final vessel is not possible. Decapeptide tends to decompose in normal post-pharmacopoeial sterilization. Therefore, the development of a lyophilisate was necessary in order to obtain an injectable solution. In any case, the amount of the active substance in the solution to be lyophilized is so small that, after drying the solutions with low concentrations of the active substances without auxiliary agents, only the fine fibers are removed from the ampoule glass wall by the steam stream used for sterilization from the container. . It is also necessary to use a frame creator to form a stable cake. At high concentrations of the active substances, these excipients can be waived. The following excipients are considered as framework makers: hexites (hexitols), especially mannitol, glucit, sorbitol, such as D-sorbitol, dulcite, allit, altrit (for example D- and L-altrit), idite (for example D- and L-idite), their optically active forms (D- or L-forms) as well as the corresponding racemates. In particular, mannitol is used, such as D-mannitol, L-mannitol, DL-mannitol, sorbitol and / or dulcite, of which mainly D-mannitol. Hexite may also be used as mixtures of said hexites, for example mixtures of mannitol and sorbitol and / or dulcite. Since dulcite is less soluble in water than for example mannitol, for example, the concentration of dulcite in an aqueous solution should not exceed 3% by weight. For example, mannitol and sorbitol can be confused in all proportions.

In addition to hexite, other conventional pharmaceutical auxiliaries, such as amino acids such as alanine, glycine, lysine, phenylalanine, aspartic acid, glutamic acid, leucine, lactose, polyvinylpyrrolidone, glucose, fructose, albumin and equivalents, may be added frames. Furthermore, urea and sodium chloride may be used as the framework's creators. The total amount of such substances in the solution used for lyophilization is, for example, -16.9% by weight, for example 0.1 - 7% by weight, relative to 1% by weight of cetrorelix. In the finished lyophilisate, the total amount of such excipients may be up to 16.9% by weight, based on one weight fraction of hexite. In detail, the amount of such excipients shall be guided by the existing amount of hexite, such that the total amount of hexite and other such excipients in the finished lyophilisate does not exceed a maximum of 17 parts by weight based on 1 weight fraction of cetrorelix. If there is only 0.1% by weight of hexite in the lyophilisate, up to 16.9% by weight of other excipients may be present; if for example 8.5

For example, by weight of 2% by weight of hexite, the amount of other excipients may be up to 8.5% by weight, relative to 1% by weight of cetrorelix.

However, from development to lyophilisate, we had to find out that the active substance behaves very differently and unpredictably during processing. The first experiments led to good results, and problems with filtering sterilization soon followed and failed batches followed.

From the literature, for example, Povvell, M. F.: Pharmaceutical Research, 1258-1263 (8) 1991; Dathe, M.: Int. J. Peptide Protein Res. 344-349 (36) 1990; Szeitli, J.: Pharmaceutical Technology International 1622, 1991 It is known that oligopeptides, especially those with a terminal acid amide function, tend to form a gel. In sterilization by filtration, this is evident at the filtration rate, and often the increased viscosity of such solutions is already organoleptic. There is a layer-like layer remaining on the sterilization filter. Thus, it is no longer possible to prepare a drug with a well-defined active substance concentration.

Table 1 lists the different outcomes of the first 11 experiments.

Active substance concentrations fluctuate between 100% and 36%.

Table 1: Cetrorelix acetate

Batch Dosage

Concentration of the active substance%

1 100 pg 100 2 500 pg 100 3 500 pg 90 4 500 pg 36 5 500 pg 100 6 500 pg 85 7 1 mg 80 8 1 mg 100 9 2 mg 100 10 2 mg 80 11 2 mg 100

-3 The following supplements have been reported in the literature to prevent this gel formation that have been used experimentally:

Organic solvents such as acetonitrile, n-butanol, tertiary butanol, ethanol, isopropanol, octanol and benzyl alcohol may be considered. Further, salts and buffer solutions such as acetate buffer, citrate buffer, sodium chloride, sodium phosphate, sodium EDTA, sodium bicarbonate, phosphate buffer, guanidine acetate, urea may be used.

Further polymers such as gelatin, polyethylene glycol 600, hydroxyethyl starch, polyvinylpyrrolidone, polyvalyl alcohol may be used. The addition of amino acids, for example alanine, glycine, lysine, phenylalanine, aspartic acid, glutamic acid and leucine, has already been described.

Citric acid, caprylic acid, octanoic acid, hydrochloric acid, sulfuric (VI) acid, and acetic acid were used. Of the physiologically acceptable surfactants, benzalkonium chloride, cetyl alcohol, bile acids, lecithin, polysorbates, Spans ^(R) and Pluronics ^{(R) are available} .

Carbohydrates and cyclodextrins such as glucose, lactose, mannitol, sucrose, alpha-, betaine gamma cyclodextrins, hydroxypropyl-alpha- and beta-cyclodextrins, hydroxyethyl cyclodextrins and methyl cyclodextrins have also been used. These excipients have been tested as filtering aids to prevent gel formation.

However, a satisfactory solution to the problem could not be determined. Acetic acid acidification alone has shown partial success. But even here, we always had to face the huge filtering losses. Surprisingly, cetrorelix has been shown to be able to dissolve well in 30% v./v. acetic acid. This solution was then filled with water for injection to a final concentration of 3% cetrorelix and mannitol added. Although it has been reported in the literature that the terminal amide group is readily hydrolyzed in an acidic medium, this has not been established with cetrorelix. The solutions prepared by this method did not work for filtration problems. We have always found the right concentrations of the active substance.

The filtration rate reaches values that ensure satisfactory production runs. The general process of sterile lyophilization is described in Sucker, Fuchs und Speiser (Herausgeber) Pharmazeutische Technologie 2nd Edition 1991, Thieme-Verlag, Stuttgart-New York, pages 557-559. A further description of the lyophilization process used is found in DE-OS 37 35 614.

Lyophilisate is used in the treatment of women's sterility. The therapeutic procedure exists so far in that

-4 All follicular maturation is stimulated by human menopausal gonadotropin and then triggered by ovulation with a dose of human chorionic gonadotropin. Such ovulation was triggered 32 hours later. The eggs thus obtained are available for fertilization outside the body.

The downside of this agonist therapy is the fact that up to 10 follicles mature in the stimulation phase. This increased follicle maturation leads to peaks in the hormonal level of LH. These peaks result in early follicular maturation and ovulation at an unanticipated time. This ovulation disorder occurs in about 25% of the cases considered and is a disadvantage because the cycle showing such ovulation disorder is lost to egg production and must be repeated about 1 month later.

A further disadvantage of the conventional stimulation process is the 4-week duration of therapy required to achieve sufficient suppression. In 1-2% of cases, agonists also show hyperstimulation syndrome in which the follicle cells hypertrophy. The risk of hyperstimulation is particularly high in polycystic ovaries. Hyperstimulation syndrome is a severe side effect that can lead to death.

In this process, however, the cetrorelix antagonist has been shown to have the following advantages:

In order to achieve total suppression, 5 days of therapy is sufficient in the cetrorelix procedure. Hyperstimulation syndrome cannot occur. In addition, HMG can be saved in phase 2 of therapy, during the ovulation initiation phase. This represents a not insignificant cost advantage of this procedure beyond bodily fertilization. Out-of-body fertilization is used for example in fallopian tubes. For this therapy, the cycle should be closely monitored and the time of ovulation determined as accurately as possible. To date, this has been achieved only to a limited extent because pre-ovulatory LH rise often occurs prematurely or does not persist for long enough due to HMG / HCG stimulation. However, it is crucial for the success of the procedure to prevent this premature rise so that the timing of fertilization can be accurately determined. This reduces the physical and mental burden of the patient and optimally utilizes clinical logistics. In order to achieve this goal with high reliability, endogenous hormone production (LH-FSH, estradiol) must be suppressed as completely as possible in order to stimulate follicular maturation and control hormonal status at the same time as the dose of exogenous gonadotropins (HMG / HCG). Only when a sufficiently high number of follicles (4-6) having approximately the same degree of maturity is reached, ovulation is initiated with a dose of HCG bolus injection.

Using the antagonist can make the procedure significantly more successful and safer for the patient.

A further scope of cetrorelix-lyophilisate according to the present invention is the use in the protection of gonads of male patients. Patients are pre-treated with cetrorelix lyophilisate and therefore

-5Support gonad activity. As a result, no other adverse effects, such as radiation therapy or cytostatic therapy, have any potential, or only minor, to affect the sensitive tissue of the gonads.

Example of manufacturing process:

Prepare approximately 1.5 liters of water for injection in a suitable glass container. Prepare 210 g of water for injection for the second glass vessel and add 91.17 g of acetic acid. The calculated amount of cetrorelix acetate (1.62-1.695 g, depending on the concentration of the batch used) was dissolved while stirring in the prepared 30% acetic acid. Transfer this solution to a glass jar with 1.5 liters of water for injection, add 82.2 g of mannitol, dissolve and make up to 3039 g with water for injection.

Control during the process:

pH value: 2.5 - 3.0 density: 1.009 - 1.017 g / cm ^{2 3} at 20 ° C refractive index: 1.227 - 1.340 at 440 nm and 20 ° C.

Sterilization of the solution is carried out by filtration through a suitable membrane filter (pore width 0.2 pm) under aseptic conditions. 100 ml of flow must be discarded. The filters must be sterilized with pressurized steam. Keep the cetrorelix solution for lyophilization protected from recontamination.

The solution is immediately dispensed into colorless DIN 2R vials, hydrolytic class I, under aseptic conditions and equipped with sterile lyophilization stoppers. The theoretical fill amount is 2.0 ml = 2.026 g.

ml of the injection bottles were washed on the bottle washer and dried with hot air and sterilized. The cleaned lyophilization stoppers were autoclaved. The pre-closed vials were transferred to a lyophilizer and frozen at a plate temperature of 40 ° C. Drying is carried out by means of a drying program at a plate temperature rising from -40 ° C to + 20 ° C. Then the device is filled with sterile nitrogen, the bottles in the device are closed and the caps are sealed with the covers closed.

-6Injection bottles are visually controlled for sealing errors and external faults. Defective injection bottles are sorted and destroyed.

Cetrorelix 1 mg lyophilisate is a white, solid lyophilized cake in a colorless 2 ml bottle closed with a gray lyophilization stopper and a yellow flipp-off trapped lid.

Claims (4)

PATENT APPLICATIONS A lyophilisate from a peptide of 3-15 amino acids and, if necessary, with one or more constituents, characterized in that 1 part by weight of the peptide is dissolved in 100-10,000 parts by weight of acetic acid and subsequently transferred to water and thus obtained the solution was lyophilized, the peptide being cetrorelix. A lyophilisate according to claim 1, characterized in that mannitol is used as the enclosure. Use of the lyophilisate obtainable according to claim 1 or 2 for the manufacture of a medicament for the treatment of female infertility. Use of the lyophilisate obtainable according to claim 1 or 2 for the manufacture of a medicament for the protection of gonads.