FIELD: chemistry.
SUBSTANCE: method of producing Form 2 of cyclosporin A, which is a kinetically stable form of cyclosporin A in aqueous suspensions. The method of producing Form 2 of cyclosporin A, characterized by basic crystal peaks of 2θ X-ray powder diffractogram at 7.5, 8.8, 10.2, 11.3, 12.7, 13.8, 14.5, 15.6 and 17.5 includes the steps of: a) preparing a suspension of cyclosporin A in a solvent containing water and an ingredient selected from the group consisting of acetonitrile, 1,4-dioxane and ethanol; b) the first heating-cooling cycle comprising heating the slurry to a temperature of 5 to 50°C, then cooling the slurry to a temperature of 1 to 35°C; c) the second heating-cooling cycle comprising heating the slurry to a temperature of 5 to 50°C, then cooling the slurry to a temperature of 1 to 35°C and d) the third heating-cooling cycle comprising heating the slurry to a temperature of 5 to 50°C, then cooling the slurry to a temperature of 1 to 35°C.
EFFECT: method improvement.
14 cl, 9 dwg, 3 tbl, 1 ex
