METHOD OF PREPARING GLYCYRRHETINIC ACID Russian patent published in 1999 - IPC

FIELD: pharmaceutical chemistry. SUBSTANCE: crude glycyrrhisic acid is hydrolyzed for 8 in aqueous medium in presence of sulfonated cationite in H form at 98-100 C and glycyrrhisic acid-to-cationite ratio 1:75. Cationite is then separated, hydrolyzate concentrated to 1/5 - 1/10 its initial volume, and ethanol is added to its final concentration 40-50%. Mixture is settled for 24 , precipitate filtered off, dissolved in 1.5-2 volumes of 95% ethanol at heating. Thereafter, alcohol solution is diluted with hot water to 40-50 vol % ethanol concentration and mixture is allowed to stand for 24 to form glycyrrhetinic acid crystals. The latter are filtered off, washed with water on filter, and dried at 100-105 C. EFFECT: increased yield and simplified procedure. 1 tbl, 2 ex