GB738543A - Method of obtaining adrenocorticotropic hormone preparation - Google Patents

Abstract

An adrenocorticotropic hormone preparation of increased potency is obtained from a protein mixture of the hormone-active and inactive components by selective adsorption with a carboxylic-type cation exchange resin. The starting material, which may be a crude extract of the pituitary gland, is dissolved or suspended in a liquid carrier, e.g. ethanol dioxan, ethylene glycol, acetone, isopropanol but preferably water, which is passed through the resin, the active component being held in the resin and the inactive component percolating through. The separation may be effected at pH 3.5 to 9.0 but a preferred pH of 8.0 to 9.0 is maintained by a buffer, e.g. alkali-metal carbonate-bicarbonate. After removal of the inactive component by washing the resin with liquid carrier of pH 8.0 to 9.0, the hormone-active fraction is eluted from the resin by continued percolation with buffered liquid carrier. Unhydrolysed protein mixture is removed at pH 8.0 to 9.0; acid-hydrolysed mixture at pH over 10; enzyme-hydrolysed mixture at pH 9.1 to 9.75; acid- and enzyme-hydrolysed protein mixture at pH 9.1 to 9.75, the first fraction eluted being enzyme-hydrolysed hormone. The percolate containing hormone-active component may be treated preferably by lyophilization, to yield a dry powder. Suitable resins are " Amberlite " (Registered Trade Mark) XE-97 and IRC-50, which may be in salt form, preferably in a finely divided state and packed in a column. The starting material may be unhydrolysed or hydrolysed, e.g. by acid or proteolytic enzyme hydrolysis, or both; or it may be purified with cellulose or oxycellulose by batch adsorption and elution techniques. Specification 681,389 is referred to.