GB694227A - Process for the manufacture of insulin preparations by extraction of insulin-containing organs - Google Patents

Abstract

Insulin extracts are obtained from insulin-containing organs by extraction with aqueous alcohol in acid medium, and is characterized in that the organs are subjected to a repeated extraction in approximately 45-55 vol. per cent alcoholic medium in the presence of one or more salts with monovalent anion in a quantity below 3 per cent by weight, with the exception of salts of the heavy metals. 3 per cent of ammonium chloride may be added to the extraction mixture and the extraction and separation effected between 5 DEG and 15 DEG C. Subsequently the pH is adjusted to between 4 and 5.5 and the precipitate removed, and the pH readjusted to 7 to 8.5 and the precipitate formed removed. The liquid is acidified, the alcohol distilled and the residue purified by salting out and precipitation at the iso-electric point. The mother liquor is brought to a pH of 6 to 8 when natural insulin precipitates. Specification 566,351, [Group VI], is referred to.ALSO:Insulin is isolated from animal organs, e.g. pancreas by extracting the organs with 45 to 55 per cent aqueous alcohol at an acid pH in the presence of one or more salts having a monovalent anion in a quantity below 3 per cent by weight, such salts not being the salts of heavy metals. Specified salts are sodium chloride, potassium chloride, potassium bromide, ammonium chloride, calcium chloride, tetramethyl ammonium chloride and sodium p-toluene sulphonic acid. It is preferred that the volume of extraction liquid be at least twice that of the organs. Extraction is at 5 to 15 DEG C. Purification involves adjusting the pH of the extract to 4 to 5.5, removing the precipitate, adjusting the pH to 7 to 8.5 and again removing the precipitated matter. The liquid is acidified, the alcohol removed in vacuo and the residue purified by salting out and precipitation at the isoelectric point. Specification 566,351 is referred to.