DD232166A3 - METHOD FOR PRODUCING STEROIDSUSPENSIONS - Google Patents

Abstract

The invention relates to a process for the preparation of steroid suspensions, which are particularly suitable for microbial transformations. Thereafter, the steroid or the steroid mixture is dissolved in an organic solvent, treated with nonionic surfactants and the solution Verduest in a hot air, gas or solvent vapor-air or solvent vapor-gas stream. The resulting powdery products result in aqueous systems highly concentrated, stable, storable, solvent-free and sterilizable suspension, which are microbially very well transformed, so have a high bioavailability.

Description

Field of application of the invention

The invention relates to a process for the preparation of suspensions of steroids or mixtures thereof, in particular for microbial transformation. The invention is thus of importance for the preparation of steroidal drugs or intermediates which are suitable for the partial synthesis of steroidal pharmaceuticals (eg contraceptives, glucocorticoids).

Characteristic of the known technical solution

It is known that the preparation of stable, readily fermentable suspensions of steroids or steroid mixtures for microbial transformations causes considerable practical difficulties due to the highly hydrophobic character of this class of substances. The main requirements of such systems are: particle size distributions whose maximum is less than 5 μm, storage stability and good spreadability in the fermentation batch. There has been no lack of attempts to get by entering the steroid from solvents, by wet grinding or micronization of the substrate as well as for a long time by the addition of nonionic detergents mostly to fermentation approach to those high steroid concentrations in this approach, which are desirable for economic reasons.

The entry of the steroid from organic solvents (such as alcohols, ketones (Herzog, HL; Payne, CC; Hyghes, MT; Gentles, NJ; Hershberg, EB; Nobile, A., Charney, W. Federbush, C; Sutter, D and Perlman, PL: Microbiological transformation of steroids-X.1-dehydro analogs of cortical steroids; Tetrahedron 18 [1962] 581-589), aliphatic acid amides or their N-ethyl derivatives (Dulaney, EL and Stapley, EO: Studies ii-deoxy-17 0-hydroxycorticosterone to hydrocortisone with a strain of Curvularia lunata, Appl. Microbiology 7 [1959], 276-284), is known per se and belongs to the most frequently used methods in steroid microbiology. The main drawback of this method is that the biological agents are loaded with the mentioned solvents, so that only relatively low substrate concentrations (15 g / l) are achievable aqueous phase large substrate crystallites arise.

Higher substrate concentrations are accessible when the steroid is taken up in a water-immiscible organic solvent and the solution is injected under boiling conditions into water or into the fermentation batch (US Pat. No. 4,124,607). In this case, however, the low storage stability of the suspensions and the toxicity of not completely removed amounts of solvent have a disadvantageous effect. Substrate preparations prepared by wet milling in ball mills (Weaver, EA, Kenney, HE andWoll, MA: Effect of concentration on the microbiological hydroxylation of progesterone, Appl Miqrobiol 8 [1960], 345-348), or by micronization (US Pat 3,201,324), although show a very small grain (5μιτι) and can be used in the fermentation process in high concentrations (50g / l), but have a limited shelf life. In addition, the production is associated with a high energy consumption.

It is also known that the method of atomization drying is used in the chemical process engineering for the production of powders or spray granules with high resolution.

It was in this context also been proposed (see FIG. Patent DD 202 994), into account in the media to be sprayed surfactants such as alkylphenyl polyglycol ethers, polyethylene glycols or fatty acid, as surfactants to outline conditions. ¹ However, this technical teaching has been proposed with the object to specifically influence the properties of the medium to be sputtered with respect to the dissolving power during sputtering, since it is assumed that these dissolution ratios have a direct influence on droplet size and droplet distribution during sputtering, thus affecting the particle size distribution in Have to be produced spray granules and finally on the dissolution rate of these granules in further processing

 The technical teaching according to patent DD 202994 is thus outside the field of technical microbiology.

Object of the invention

The aim of the invention is the recovery of steroid suspensions, in particular for the purpose of better implementation of the steroids in the microbiological transformation.

Explanation of the essence of the invention

The invention has for its object to provide a technologically simple method, since it allows the avoidance of the disadvantages of the known technical solutions to produce about the intermediate step of obtaining steroid-surfactant mixtures such suspensions that effectively the microbiological transformation of steroids or Steroid mixtures can be accomplished.

According to the invention the object is achieved by reacting a steroid or a steroid mixture, preferably a sterol (such as sitosterol, campesterol or cholesterol) or a sterol mixture (such as sitosterol-campesterol mixture or sitosterol-cholesterol mixture), first in concentrations of 0.1 kg / l to 0.5 kg / l, preferably of 0.15 kg / l, dissolved in an organic solvent. The organic solvent used is an alcohol, preferably methanol or ethanol, or a ketone, preferably acetone, or a hydrocarbon, preferably an aliphatic to C ₈ , or a halohydrocarbon, preferably methylene chloride or chloroform.

Already in the next step, the solution is mixed with a nonionic surfactant in concentrations of 0.01% to 50% with respect to the steroid or steroid mixture used. As surfactants are either sorbitan or Polyethylenglykolsorbitanfettsäureester, z. As polyoxyethylene sorbitan monooleate or monopalmitate used.

The resulting steroid-surfactant or steroid mixture surfactant solution, after it has optionally been filtered, in conventional spray driers at temperatures of 60 ⁰ C to 14O ⁰ C, preferably up to 120 ⁰ C, in the gas phase, ie in a hot Air or gas or solvent vapor-air or solvent vapor gas stream, injected or sprayed. As a result of the previous process steps, the spraying of the steroid substrates is technologically easy and feasible with high efficiency.

The resulting powdery product is then suspended in aqueous media, such as in mineral nutrient media, in complex culture media or in aqueous buffer systems (such as Sörensen phosphate buffer).

Stable aqueous steroid suspensions having a substrate content of up to 60% can be prepared by this process, and fermentation cultures for the purpose of microbial steroid transformations containing steroid suspensions prepared in this way have a markedly increased bioavailability of the steroid.

Furthermore, it has been found that the steroid suspensions produced according to the method

- Are largely free of residues of the organic solvent, so that no risk to the Fermentätionskultur arises, and

- Both are well storable and well sterilizable.

embodiments

1. 600 g Rohsitosterol from the tall oil preparation are dissolved with the addition of 60g Polyoxyethylensorbitanmonooleat in 4I chloroform. The filtered solution is heated in a 120 ° C air stream, e.g. atomized in a laboratory spray dryer. The resulting finely divided product is suspended in 11 aqueous nutrient medium and can be used after sterilization for the fermentation.

2. 2kg sitosterol-campesterol mixture are dissolved in 8I methylene chloride. To the solution are added 50 g of polyoxyethylene sorbitan monooleate. The solution is atomized in a hot nitrogen stream in a spray dryer. The resulting powdery product is suspended in buffer solution and can be used for fermentation after sterilization.

3. 4kg of sitosterol are dissolved in 3 liters of methylene chloride. 400 g of polyoxyethylene sorbitan monopalmitate are added to the solution and the solution is atomized in the hot stream of methylene chloride-air vapor which is circulated through a condenser for the methylene chloride. The resulting product is suspended in nutrient solution and can be used for fermentation after sterilization.

Claims (5)

- ι. - two yes Invention claim: 1. A process for the preparation of steroid suspensions for the microbial transformation by spray drying of solutions of steroids in organic solvents and then adding the resulting powdery product in an aqueous medium, characterized in that the steroid feed solution with a concentration of 0.1 kg / l to 0 , 5 kg / l steroid then 0.01% to 50%, based on the amount of steroid, of a nonionic surfactant are added and the resulting steroid-surfactant mixture is then injected at temperatures between 60 ° C and 14O ⁰ C in a sputtering dryer. 2. The method according to item 1, characterized in that are preferably used as steroids sterols, such as sitosterol, campesterol or cholesterol, or sterol mixtures, such as sitosterol-campesterol mixture or sitosterol-cholesterol mixture. 3. The method according to item 1 and 2, characterized in that as organic solvents in the steroid use solution alcohols, such as methanol or ethanol, or ketones, such as acetone, or hydrocarbons, in particular the aliphatic to C ₈ , or halogenated hydrocarbons, such as methylene chloride or Chloroform can be used. 4. The method according to item 1 to 3, characterized in that as nonionic surfactants preferably sorbitan or Polyethylenglykolsorbitanfettsäureester, so in particular Polyoxymethylensorbitanmonooleat or monopalmitate, are used. 5. The method according to item 1 to4, characterized in that the resulting steroid-surfactant mixture in the hot air or gas or solvent vapor-air or solvent vapor gas stream is injected at 120 ° C.