PROCESS FOR THE PREPARATION OF STABLE, CRYSTALLINE, STABLE PROSTAGLANDIN F2A FOUNDING ABOVE 35 OC FROM PROSTAGLANDIN F2A IMPURE CONTAINING 50 TO 98 PROSTAGLANDIN F2A

摘要

The invention relates to a crystalline, stable prostaglandin F2 alpha (PGF2 alpha ) having a melting point above 35 DEG C and its preparation from impure PGF2 alpha of 50-98% PGF2 alpha content, according to which the impure prostaglandin F2 alpha containing 50-98% of prostaglandin F2 alpha is dissolved in - calculated relative to the weight of the PGF2 alpha added - 3-7 parts by weight of water containing 1-1.5 equivalents of alkali metal hydroxide, carbonate or bicarbonate, the aqueous solution obtained is extracted with a water-immiscible organic solvent, the extracted solution is diluted with water to a concentration of 1.25-30 g of prostaglandin F2 alpha /litre, the pH of the solution is adjusted with an acid or an acidic salt of a polybasic acid to 4-6 and the deposited impurities are removed, 0.05-0.2 kg of sodium chloride per litre is dissolved in the pure aqueous solution obtained, the pH of the solution is adjusted with an acid or an acidic salt of a polybasic acid to 2-4 and the solution is extracted with a water-immiscible organic solvent, the organic extract is freed of water and concentrated, the residue obtained is dissolved in anhydrous lower alkanol, the solution obtained is concentrated up to an alkanol content of 5-20% and crystallised, optionally after adding a lower ether, ester, aliphatic or aromatic hydrocarbon or halogenated derivatives thereof in an amount of at most 50% of the PGF2 alpha content of the solution. The invention also relates to pharmaceutical preparations which contain the crystalline, stable PGF2 alpha crystal modification melting above 35 DEG C as active substance.