Highly purified gonadotropin compositions and process for preparing them

A purification process for obtaining the human urinary gonadotropins follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH) of high biological activity and chemical purity absolutely free of foreign contaminating materials derived from the use of biological reagents or chromatography dyes, from crude gonadotropins comprising FSH LH, said process comprising the following steps:

• 1) purifying said gonadotropins diluted in 0.05–0.15 M ammonium acetate, pH5.0–6.0, in an ionic exchange column with a strong cationic sulfopropyl resin, eluting both FSH and LH with solutions of 0.05–0.5 M ammonium acetate, pH 5.0–7.0;
• and
• 2) purifying the gonadotropins diluted in 0.01–0.05 M ammonium acetate, pH 5.0–7.0, in an ion exchange column with a strong anionic resin of the quaternary ammonium type, eluting both FSH and LH with solutions of 0.05–0.2 M ammonium acetate, pH 5.0–7.0;
• and
• 3) purifying the gonadotropins in a column with an hydrophobic interaction resin by sequential addition of at least two of the following solutions:
• a) buffer of 50–200 mM sodium phosphate, and 0.8–1.2 M ammonium sulfate, pH 5.0–6.0;
• b) buffer of 50–200 mM sodium phosphate, and 0.4–0.6 M ammonium sulfate;
• pH 5.0–7.0;
• c) buffer of 50–200 mM sodium phosphate (50–70% v/v), and ethanol 96% (50–30% v/v), and
• 4) recovering purified FSH and/or LH;
• wherein steps 1 to 3 may be performed in any order.