GB840870A - Improvements in or relating to insulin preparations - Google Patents

Abstract

A quick-acting insulin preparation is prepared by dissolving insulin derived from pig pancreas in an aqueous injectable medium having or being given a pH value of between 7 and 8. A solution of a compound of one or more metals that are prerequisite to the crystallization of insulin, i.e. zinc, cobalt, nickel or cadmium may be added providing the total metal content of the solution does not exceed about 13 X A X 10-13 milli equivalents per litre, A being the number of international units of insulin per millilitic. Buffering agents, for example, phosphate, citrate, acetate, borate, maleate, diethyl barbiturate and glycerol buffers may also be present. If the buffer used is capable of forming complexes with the metal ions present, the amount of metal compound added may exceed the above stated amount providing the free metal ions in solution do not exceed the limit. An example given is the preparation of an 0.02M aqueous solution of sodium acetate containing per litre 1.74 gms. (40,000 international units) of crystalline insulin derived from pig pancreas and containing about 0.7% zinc, 2 ml. N hydrochloric acid, 1 gm. methyl-p-hydroxybenzoate, 1.4% by weight NaCl, the pH being adjusted to 7.3 to 7.5 with sodium hydroxide.