WO1999059541A2

WO1999059541A2 - Cyclosporin preparations

Info

Publication number: WO1999059541A2
Application number: PCT/EP1999/003002
Authority: WO
Inventors: Robert Heger; Helmut Auweter; Peter PFLÜGER; Jörg Breitenbach; Rudolf Binder; Jürgen Zeidler; Gunther Berndl
Original assignee: Basf Aktiengesellschaft
Priority date: 1998-05-15
Filing date: 1999-05-04
Publication date: 1999-11-25
Also published as: NO20005769L; NO20005769D0; EP1077676A2; JP2002515415A; CA2332270A1; WO1999059541A3; AU3930399A; CN1301171A; DE19821951A1

Abstract

The invention relates to solid or liquid cyclosporin preparations for oral administration in which the cyclosporin is presented in the form of solid X-amorphous particles embedded in a coating matrix in a colloidally dispersed manner.

Description

Cyclosporin preparations

description

5

The present invention relates to cyclosporin preparations in which the cyclosporin is present colloidally in the form of solid, X-ray amorphous particles.

10 Cyclosporins, a series of non-polar, cyclic oligopeptides, are characterized by their immunosuppressive effect. Among them, the 11-amino acid cyclosporin A obtained by fermentation has gained therapeutic importance.

15

Although cyclosporin formulations have been developed for both oral and intravenous use, oral administration of cyclosporin is preferred because it ensures better patient compliance.

20th

However, cyclosporin A, which is quite large with a molecular weight of 1202 g / mol, has a high lipophilicity, which at the same time manifests itself in a very low water solubility (<0.004% m / V). Due to a certain solubility in oils such as olive

25 oil as well as in ethanol, it became possible to develop emulsion concentrates which, when administered orally, lead to an albeit relatively variable bioavailability of approximately 30% (cf. RH Müller et al. In "Pharmaceutical Technology: Modern Pharmaceutical Forms", Scientific Publishing Company) Stuttgart

30 1997, pp. 118-125).

Accordingly, oral forms currently available on the market are either emulsion concentrates for administration as solutions or microemulsions filled in capsules. In both cases 35 solvents such as ethanol and / or oil are used to solubilize the cyclosporin.

The bioavailability can, however, be subject to strong fluctuations in the range from 10 to 60%. These fluctuations 40 are related to the galenic form and the condition of the preparation in the gastrointestinal tract. Furthermore, natural fat digestion has a significant influence on the absorption of the cyclosporin administered orally.

45 WO 97/07787 also describes cyclosporin formulations which, in addition to the active ingredient, contain an alkanolic solvent such as ethanol or propylene glycol and a nonionic polyoxyalkylene derivative as a surface-active substance.

A disadvantage of such forms is, on the one hand, that they contain solvents, especially ethanol, and, on the other hand, that the cyclosporin tends to recrystallize at low temperatures, which is problematic in terms of storage stability. Such precipitates are largely not absorbed, so that even bioavailability may not be guaranteed.

EP-A 425 892 discloses a process for improving the bioavailability of active pharmaceutical ingredients with peptide bonds, wherein a solution of the active ingredient in a water-miscible organic solvent is rapidly mixed with an aqueous colloid, so that the active ingredient is in a colloidally dispersed form Shape fails.

WO 93/10767 describes oral administration forms for peptide medicaments in which the medicament is incorporated into a gelatin matrix in such a way that the colloidal particles which form are present in a charge-neutral manner. A disadvantage of such forms, however, is their tendency to flocculate.

The object of the present invention was to find dosage forms of cyclosporin which are suitable for oral administration and which are free from solvents and whose bioavailability is comparable to the microemulsions.

Accordingly, solid cyclosporin preparations have been found in which the cyclosporin is present in the form of solid, X-ray amorphous particles in a colloidal dispersion in a matrix of a polymeric coating material.

According to the invention, all cyclosporins can be processed, but cyclosporin A is preferred. Cyclosporin A has a melting point of 148-151 ° C. and is used as a colorless, crystalline substance.

In the preparations according to the invention, the cyclosporin is particulate embedded in an envelope matrix consisting of one or more polymeric stabilizers. Suitable polymeric stabilizers according to the invention are swellable protective colloids such as, for example, beef, pork or fish gelatin, starch, dextrin, pectin, gum arabic, lignin sulfonates, chitosan, polystyrene sulfonate, alginates, casein, caseinate methyl cellulose, carboxymethyl cellulose, hydroxypropyl dextran, milk powder or skimmed milk or mixtures of these protective colloids. Homopolymers and copolymers based on the following monomers are also suitable: ethylene oxide, propylene oxide, acrylic acid, maleic anhydride, lactic acid, N-vinylpyrrolidone, vinyl acetate, α- and β-aspartic acid. One of the gelatin types mentioned is particularly preferably used, in particular acidic or basic degraded gelatin with Bloom numbers in the range from 0 to 250, very particularly preferably gelatin A 100, A 200, B 100 and B 200 and low molecular weight, enzymatically degraded gelatin types with the Bloom number 0 and molecular weights from 3,000 to 30,000 D such as Collagel A and Gelitasol P (Stoess, Eberbach) or chemically modified gelatin such as Gelafundin (B. Braun, Melsungen) and mixtures of these gelatin Sorts.

The preparations also contain low molecular weight surface-active compounds. As such, amphiphilic compounds or mixtures of such compounds are particularly suitable. Basically, all surfactants with an HLB value of 5 to 20 can be used. Examples of suitable surface-active substances are: esters of long-chain fatty acids with ascorbic acid, mono- and diglycerides of fatty acids and their oxyethylation products, esters of monofatty acid glycerides with acetic acid, citric acid, lactic acid or diacetyl tartaric acid, polyglycerol fatty acid esters such as e.g. the monostearate of triglycerin, sorbitan fatty acid ester, propylene glycol fatty acid ester, 2- (2'-stearoyllactyl) lactic acid salts and lecithin. Ascorbyl palmitate is preferably used.

The amounts of the various components are chosen according to the invention so that the preparations 0.1 to 70% by weight, preferably 1 to 40% by weight, of cyclosporin, 1 to 80% by weight, preferably 10 to 60% by weight. % of one or more polymeric stabilizers and 0 to 50 wt .-%, preferably 0.5 to 20 wt .-% of one or more low molecular weight stabilizers. The percentages by weight relate to a dry powder.

In addition, the preparations can also contain antioxidants and / or preservatives to protect the cyclosporin. Suitable antioxidants or preservatives are, for example, α-tocopherol, t-butylhydroxytoluene, t-butylhydroxyanisole, lecithin, ethoxyquin, methylparaben, propylparaben, sorbic acid, Sodium benzoate or ascorbyl palmitate. The antioxidants or preservatives can be present in amounts of 0 to 10% by weight, based on the total amount of the preparation. It may also be advisable to add lipoprotein blockers to the preparations in order to improve the absorption of the cyclosporin, for example polyoxyethylene cholesterol ether.

The preparations may also contain plasticizers to increase the stability of the end product. Suitable plasticizers are, for example, sugars and sugar alcohols such as sucrose,

Glucose, lactose, invert sugar, sorbitol, mannitol, xylitol or glycerin. Lactose is preferably used as the plasticizer. The plasticizers can be contained in amounts of 0 to 50% by weight.

Furthermore, the preparations can also contain edible oils and / or fats to increase the colloidal stability of the preparation according to the invention. Suitable oils and fats are e.g. of vegetable origin such as sunflower oil, peanut oil, corn oil, linseed oil, olive oil, poppy oil, rape oil, castor oil, coconut oil, aradis oil, soybean oil, palm oil or cottonseed oil. Other suitable oils or fats are fish oils, cattle claw oil, lard, beef chalk and butterfat. The oils and fats can be contained in the preparation according to the invention in the range from 0 to 50% by weight, based on cyclosporin. In the formulation, the oil or fat is stored in the colloidal particles containing solid cyclosporin. When choosing the type and amount of oil or fat, it is crucial that the colloidal cyclosporin-containing particles continue to be present as solid particles at application temperatures (T <40 ° C.).

Other pharmaceutical auxiliaries such as binders, disintegrants, flavors, vitamins, colorants, wetting agents, additives influencing the pH value (cf. H. Sucker et al., Pharmaceutical Technology, Thieme-Verlag, Stuttgart 1978) can also be used via the organic solvent or aqueous phase are introduced.

To carry out the process according to the invention, a solution of the cyclosporin is first prepared in a suitable solvent, solution in this context meaning a true molecularly disperse solution or a melt emulsion. Suitable solvents are organic, water-miscible solvents which are volatile and thermally stable and contain only carbon, hydrogen and oxygen. It is expedient for them to be at least 10% by weight miscible with water and have a boiling point below 200 ° C. and / or have less than 10 carbon atoms. Corresponding alcohols are preferred. hole, esters, ketones and acetals. In particular, ethanol, n-propanol, isopropanol 1,2-butanedio-1-methyl ether, 1,2-propanediol-in-propyl ether or acetone are used.

According to one embodiment of the process, a molecularly disperse solution of the cyclosporin in the selected solvent is dissolved at temperatures in the range from preferably 20 to 150 ° C. within a period of less than 120 seconds, preference being given, if appropriate, to an excess pressure of up to 100 bar - wise 30 bar, can work.

According to a further preferred embodiment, the cyclosporin solution is prepared in such a way that the mixture of cyclosporin and solvent is heated to 150 to 240 ° C. over a period of less than 10 seconds above the melting point of the cyclosporin, optionally with an excess pressure of can work up to 100 bar, preferably 30 bar.

The concentration of the cyclosporine solution thus prepared is generally 10 to 500 g of cyclosporine per 1 kg of solvent. In a preferred embodiment of the process, the low molecular weight stabilizer is added directly to the cyclosporin solution.

In a subsequent process step, the

Cyclosporin solution mixed with an aqueous solution of the polymeric shell material. The concentration of the solution of the polymeric coating material is 0.1 to 200 g / 1, preferably 1 to 100 g / 1.

In order to achieve the smallest possible particle sizes during the mixing process, a high mechanical energy input is recommended when mixing the cyclosporin solution with the solution of the coating material. Such energy input can take place, for example, by vigorous stirring or shaking in a suitable device, or by injecting the two components into a mixing chamber with a hard jet, so that vigorous mixing occurs.

The mixing process can be carried out batchwise or, preferably, continuously. As a result of the mixing process, cyclosporin precipitates in the form of solid, X-ray amorphous particles. The suspension or colloid obtained in this way can then be converted into a dry powder in a manner known per se, for example by spray drying, freeze drying or drying in a fluidized bed The preparation of the preparations according to the invention is carried out by adjusting the pH of the solution of the shell material, in particular gelatin, and a solution of cyclosporin in such a way that no charge neutrality occurs in the cyclosporin particles which forms, that is to say that the pH of the

Do not adjust the gelatin solution to such a value that a charge-neutral state is created when the particles form.

The average particle diameter of the solid cyclosporin particles in the matrix of the polymeric shell material is 20 to 1000 nm, preferably 100 to 600 nm. Surprisingly, the spherical cyclosporin particles are completely X-ray amorphous. In this context, X-ray amorphous means the absence of crystal interference in X-ray powder diagrams (cf. H.P. Klug, L.E. Alexander, "X-Ray Diffraction procedures for Polycrystalline and Amorphous Materials, John Wiley, New York, 1959).

The dry powders obtained according to the invention can be used in all customary oral dosage forms. For example, the powders can be filled into hard or soft gelatin capsules or compressed into tablets using the usual aids.

Because of their good redispersibility in water, the powders are also suitable for use as drinking forms, for example as drinking granules, in effervescent tablets, juices, syrup forms or in sachets, and for parenteral applications. Even after redispersion, uniform, finely divided suspensions (hydrosols) or colloids are obtained.

The preparations according to the invention not only offer the advantage that they are completely free from solvents such as ethanol, but also have good bioavailability which is quite comparable to that of the microemulsions. In view of the prior art, such a good bioavailability was not to be expected for a preparation which contains cyclosporin in solid form.

The results of a dog study demonstrate the good bioavailability of the preparation compared to a market product.

Production Example 1

Production of a cyclosporin dry powder with an active substance content in the range of 10% by weight a) Production of the micronizate

3 g of cyclosporin A were stirred into a solution of 0.6 g of ascorbyl palmitate in 36 g of isopropanol at 25 ° C., a clear solution being formed.

To precipitate cyclosporin A in colloidally dispersed form, this molecularly disperse solution was fed to a mixing chamber at 25 ° C. There, the mixture was mixed with 537 g of an aqueous solution adjusted to pH 9.2 using 1 N NaOH

Solution of 14.4 g gelatin B 100 Bloom and 12.6 g lactose in deionized water. The entire process was carried out with a pressure limit of 30 bar. After mixing, a colloidally disperse cyclosporin A dispersion with a white, cloudy color was obtained.

The mean particle size was determined to be 256 nm with a variance of 31% by quasi-elastic light scattering. Using Fraunhofer diffraction, the mean value of the volume distribution was determined to be D (4.3) = 0.62 μm with a fine fraction of the distribution of 99.2 <1.22 μm.

b) drying the dispersion a) to a nanoparticulate dry powder

Spray drying of the product la) gave a nanoparticulate dry powder. The active ingredient content in the powder was determined by chromatography to be 9.95% by weight. The dry powder dissolves in drinking water to form a white, cloudy dispersion (hydrosol).

c) X-ray wide-angle scattering

In Figure 1, the scatter curves of active ingredient (top and dry powder according to lb) (bottom) are shown. The cyclosporin starting material, as evidenced by the X-ray diagram, which is distinguished by a series of sharp interferences, is crystalline; in contrast, the scatter curve of the dry powder only shows diffuse, broad interference maxima, as are typical for an amorphous material. The active substance is therefore present in the dry powder produced according to lb) in an X-ray amorphous manner. This also applies to the otherwise crystalline auxiliaries lactose and ascorbyl palmitate. d) Cryo Replica Transmission Electron Microscopy (Cryo TEM)

FIG. 5 shows a cryo-TEM image of the dry powder redispersed in tap water according to lb). The spherical nanoparticulate cyclosporin particles with an average diameter of D = 500 nm are clearly visible. This figure shows that after the redispersion of the dry powder, a colloidally disperse cyclosporin solution is formed again, in which the individual colloid particles are not aggregated.

Preparation example 2

Production of a cyclosporin dry powder with an alcohol content in the range of 15% by weight

a) Production of the micronizate

3 g of cyclosporin A were stirred into a solution of 0.6 g of ascorbyl palmitate in 18 g of isopropanol and 18 g of deionized water at 25 ° C. This solution was converted into the molecularly dissolved state by heating in a heat exchanger. The residence time of the cyclosporin solution in the heat exchanger was 90 min, a temperature of a maximum of 135 ° C. not being exceeded.

To precipitate cyclosporin A in a colloidally dispersed form, this molecularly disperse solution was fed to a mixing chamber at 135 ° C. There it was mixed with 393.9 g of an aqueous solution adjusted to pH 9.2 using 1 N NaOH

Solution of 9.2 g gelatin A 100 Bloom and 6.1 g lactose in deionized water. The process was carried out under pressure limitation to 30 bar to prevent the water from evaporating. After mixing, a colloidally disperse cyclosporin A dispersion with a white, cloudy shade was obtained.

The mean particle size was determined to be 285 nm with a variance of 48% by quasi-elastic light scattering. The mean value of the volume distribution was determined by means of Fraunhofer diffraction to D (4.3) = 0.62 μm with a fine fraction of the distribution of 99.8% <1.22 μm

b) drying the dispersion 2a) to a dry powder

Spray drying the dispersion resulted in a nanoparticulate dry powder. The active substance content in the dry powder was determined by chromatography to be 15.9% by weight. The dry powder dissolves in drinking water with the formation of a cloudy white color

Dispersion.

The average particle size was determined immediately after redispersion to be 376 nm with a variance of 38% by quasi-elastic light scattering. Using Fraunhofer diffraction, the mean value of the volume distribution was determined to be D (4.3) = 0.77 μm with a fine fraction of the distribution of 84.7% <1.22 m.

Freeze drying of the product resulted in a nanoparticulate dry powder. The active ingredient content in the powder was determined by chromatography to be 16.1% by weight of cyclosporin. The dry powder dissolved in drinking water to form a white, cloudy hydrosol.

The average particle size was determined by quasi-elastic light scattering immediately after redispersion to be 388 nm with a variance of 32%. Using Fraunhofer diffraction, the mean value of the volume distribution was determined to be D (4, 3) = 0.79 μm with a fine fraction of the distribution of 82.4% <1.22 μm.

Microelectrophoresis

FIG. 3 shows the pH-dependent mobility curves of an aqueous dispersion of active ingredient, gelatin and dry powder according to 2b) (spray drying). The mobility curve of the crystalline cyclosporin A used as the starting material differs significantly in the level of mobility and the position of the isoelectric point from that of the micronized dry powder according to 2b). The isoelectric point of the redispersed dry powder coincides with that of the gelatin used. This shows that the nanoparticulate cyclosporin particles are embedded in a gelatin shell.

Preparation example 3

Analogously to example 2a), a colloidally disperse cyclosporin A dispersion was prepared from 4.5 g of cyclosporin A, 0.9 g of ascorbyl palmitate, 9.6 g of gelatin A 100 Bloom and 7.2 g of lactose.

The mean particle size was determined to be 280 nm with a variance of 21% by quasi-elastic light scattering. The mean value of the volume distribution was determined by means of Fraunhofer diffraction D (3.4) = 0.62 μm with a fine fraction of the distribution of 99.2% <

1.2 μm determined.

b) drying the dispersion 3a) to a nanoparticulate dry powder

A nanoparticulate dry powder with a cyclosporin A content (determined by chromatography) of 19.9% by weight was obtained by spray drying. The dry powder dissolved in drinking water to form a white, cloudy dispersion (hydrosol).

The mean particle size was determined immediately after redispersion to be 377 nm with a variance of 45% by quasi-elastic light scattering. The mean value of the volume distribution was determined by means of Fraunhofer diffraction to D (4, 3) = 0.62 μm with a fine fraction of the distribution of 83.3% <1.2 μm.

Figure 3: X-ray wide-angle scattering dry powder 2b) and 3b)

3 shows the scatter curves of the dry powder obtained in each case by spray drying according to 2b) (upper curve) and 3b) (lower curve), in contrast to the scatter curve of the crystalline cyclosporin starting material, which contains sharp interferences, shown in FIG. 1, show the scatter curves the dry powder only exhibits diffuse, broad interference maxima, as are typical for amorphous materials.

Preparation example 4

A preparation was produced in the same way as in production example 3, in which fish gelatin with molecular weight fractions of 10 ³ to 10 ⁷ D was used as the coating matrix material.

Pharmacokinetic properties of dry powder

Blood level kinetics in dogs: general method

Cyclosporin was administered in the corresponding preparation to beagle dogs with a weight in the range from 8 to 12 kg either orally as a solid form or by gavage in liquid forms. Liquid forms were placed in 50 ml of water and rinsed with a further 50 ml of water. Solid forms were administered without water. The feed was withdrawn from the animals 16 h before the substance was administered, and the animals were fed again 4 h after the substance was administered. The dogs were given substance before and in the time grid up to 32 h after substance administration, blood was drawn from the jugular vein or the antebrachial vein in heparinized vessels. The blood was frozen and stored at -20 ° C until analytical processing. Blood levels were determined using a validated, internally standardized GC-MS method.

Form 1 (for comparison): Sandimmun Optoral, capsule, 100 mg active ingredient

Form 2: dry powder according to preparation example 1, active ingredient dose 100 mg; Administration as Hydroso1

Form 3: dry powder according to preparation example 3, active ingredient dose 100 mg administration as hydrosol

the medians of the corresponding blood levels are given in FIG. It can clearly be seen that with forms F2 and F3 according to the invention a faster increase in blood level values is achieved at the beginning than with the comparative form F1.

Areas below blood level curves and relative bioavailability

table

Form 1 (Sandimmun Optoral)

AUC: Area under the curve

BV: Bioavailability tmax: [h]

Cmax: [ng / ml] Form 2

Form 3

Preparation example 4

Production of a cyclosporin dry powder with an active substance content in the range of 15% by weight

Production of the micronisate

3 g of cyclosporin A were stirred into a solution of 0.6 g of ascorbyl palmitate and 0.3 g of soybean oil in 18 g of isopropanol and 18 g of completely deionized water at 25 ° C., so that a cloudy, coarsely disperse solution was formed. This solution was converted into the molecularly dissolved state by heating in a heat exchanger. The residence time of the cyclosporin solution in the heat exchanger was approx. 90 min, a temperature of a maximum of 135 ° C. not being exceeded.

To precipitate cyclosporin A in a colloidally dispersed form, this molecularly disperse solution was fed to a mixing chamber at 135 ° C. There, the mixture was mixed with 412.3 g of an aqueous solution of 8.9 g of gelatin A 100 Bloom and 6.5 g of lactose in demineralized water, which had been adjusted to pH 9.2 using 1 N NaOH. The entire process was carried out under pressure limitation to 30 bar in order to evaporate the solution means to prevent. After mixing, a colloidally disperse cyclosporin A dispersion with a white, cloudy color was obtained.

The mean particle size was determined to be 273 nm with a distribution width of ± 37% by quasi-elastic light scattering. The mean value of the volume distribution was determined by means of Fraunhofer diffraction to D (4.3) = 0.62 μm with a fine fraction of the distribution of 99.8% <1.22 μm.

Drying the dispersion from a) to a nanoparticulate dry powder

Spray drying of the product from the manufacturer's example resulted in a nanoparticulate dry powder. The active substance content in the powder was determined by chromatography to be 15.21% by weight of cyclosporin A (theoretical value: 15.54% by weight). The dry powder dissolves in drinking water to form a white cloudy dispersion (hydrosal).

The average particle size was determined immediately after redispersion to be 352 nm with a distribution width of ± 42% by quasi-elastic light scattering. The mean value of the volume distribution was determined by means of Fraunhofer diffraction to D (4.3) = 0.73 μm with a fineness of the distribution of 86.3% <1.22 μm.

Claims

claims

1. Solid or liquid cyclosporin preparations for oral administration, in which the cyclosporin is present in the form of solid, X-ray amorphous particles colloidally dispersed embedded in an envelope matrix.

2. Cyclosporin preparations according to claim 1, with an average particle diameter of the cyclosporin particles in the range of 20 to 1000 nm.

3. Cyclosporin preparations according to claim 1 or 2, containing one or more edible oils or fats or mixtures of such oils and fats.

4. Cyclosporin preparation according to one of claims 1 to 3, containing one or more low molecular weight surface-active compounds.

5. Cyclosporin preparations according to one of claims 1 to 4, containing as a polymeric coating matrix casein or caseinate.

6. Cyclosporin preparations according to one of claims 1 to 4, containing gelatin as a polymeric coating matrix.

7. Cyclosporin preparation according to one of claims 1 to 6, containing ascorbyl palmitate as a low-molecular surface-active substance

8. A process for the preparation of preparations according to one of claims 1 to 7, characterized in that a precipitation by mixing a solution of the cyclosporin in water or a water-miscible organic solvent with an aqueous solution of a protective polymer colloid with the input of mechanical energy of the cyclosporin particles.