Clinical Biopotency of Insulin Analogues: Comparative Assessment in Different Species

Objective: The clinical potency of human insulin has classically been evaluated following the U.S. Pharmacopeia (USP) guideline for comparison to an international standard (IS) of activity (IU). However, since insulin analogues cannot be standardized against IS, there is a need for a bioassay to assess clinical specific activity (U). To this extent, we compared the biopotency (U) of different insulin products in different species and used human (recombinant) and pork (natural) insulin as reference standards. Methods: New Zealand White rabbits were fasted and injected subcutaneously (s.c.) at a dose level of 0.5 U/kg. Diabetic Yucatan miniature swine (Sus scrofa) were injected s.c. at dose level of 0.1 U/kg. Normal insulin suppression tests (nIST) were conducted in primates (Macaca fascicularis) receiving a bolus intravenous (i.v.) infusion of glucose. Insulin products were given at dose level of 0.05 U/kg. Glucose levels were recorded using handheld glucometer devices. The blood glucose kinetic (BGPK), th...