Human insulin.

Abstract

Two methods of synthesis of human insulin have been developed to the stage of commercial production. One entails synthesis of human insulin by bacteria ("biosynthetic" human insulin) and one entails the conversion of pork insulin into human insulin by an amino acid substitution ("semisynthetic" human insulin). Both forms of human insulin have been shown to be safe, and to have similar efficacy and pharmacokinetics to purified pork insulin. Human insulin given by subcutaneous injection has been shown to elicit antibody formation in man, although the extent of this may be slightly less than in the case of purified pork insulin, and is certainly less than in the case of beef insulin and beef-pork combinations. The clinical significance of these differences in immunogenicity is doubtful. However there are rare defined situations, such as allergy to pork insulin and antibody-mediated insulin resistance where human insulin has been shown to have advantages over purified pork insulin. Bacterial synthesis of insulin provides an assured supply for the world's future needs, and it is conceivable that further technological refinement may make bacterial synthesis cheaper than extraction and purification of animal insulins. However, current evidence provides no basis for recommending human rather than purified animal insulin for the routine management of insulin dependent diabetes.