Galenics of Insulin: The Physico-chemical and Pharmaceutical Aspects of Insulin and Insulin Preparations

Galenical pharmacy or galenics is the science dealing with the pro­ duction of drug substances from raw materials, the purity of such substances, their formulation into pharmaceutical preparations with the desired effects and safety in use, and the quality control, stability and storage of the preparations. The field has taken its name from the Greek physician Galen (131-201 A.D.), who had a profound influence on medicine for many centuries because he collected and systematized the medicinal knowledge of his time. The discovery of insulin is attributed to Banting and Best who, in 1921, prepared an extract of the pancreas of the fetal calf and showed that the extract was capable of reducing the blood sugar level of a diabetic dog. This outstanding discovery gave rise to the rapid develop­ ment of the manufacture of insulin of bovine and porcine origin. By 1925, two Danish manufacturers of insulin preparations were established; both have since been in the forefront ofthe development of insulin preparations, the latest achievement being the marketing of human insulin by Novo in 1982. The development of highly purified human insulin produced semisynthetically from porcine insulin or by DNA recombinant methods are significant contributions to safe and efficient insulin therapy. Insulin is a protein which is destroyed in the gastrointestinal tract.