GB797959A - Improvements in or relating to the preparation of insulin - Google Patents

Abstract

Insulin is prepared from an insulin containing acidified alcoholic pancreatic extract by contacting said extract with a cation exchanger, eluting the insulin therefrom and precipitating the insulin from the eluate, e.g. by saturating the eluate with sodium chloride. The extract, which may have a pH of at least 3, may be cooled to about -5 DEG C. and centrifuged to separate solid fats and proteins prior to contacting with the cation exchanger. Neutral salts and proteinaceous impurities may be precipitated by rendering the extract neutral or about pH 8 with ammonia, the filtrate being then adjusted to pH 3 by contact with a sulphonated highly criss-linked cation exchanger, e.g. "Dowex," which is removed and the separated liquor contacted with the carboxylic cation exchanger. The cation exchanger may be a synthetic or naturally occuring carboxyl group-containing material, e.g. "Amberlite" (Registered Trade Mark), oxycellulose, pectic acid or alginic acid and the elution may be effected with a mineral acid, e.g. sulphuric or hydrochloric acid. The alcohol used in the extraction of the pancreas may contain from 1 to 4 carbon atoms, e.g. methanol, ethanol, and may be acidified with an organic or inorganic acid, e.g. acetic, citric, oxalic, hydrochloric acid.