[The Human Insulin Reference Standard (Control 921) of the National Institute of Health Sciences].

Raw human insulin material was examined for preparation of the "Human Insulin Reference Standard". The candidate material was evaluated by a domestic collaborative study in which four laboratories participated. The biological activity was determined to be 26.0 Unit/mg against the International Human Insulin Reference Standard (Code 83/500), based on the rabbit blood-glucose method specified in the JP XII (1991). Because of the possibility of application as a chemical reference standard for assay by the HPLC method, a physico-chemical evaluation of the candidate material was also performed. The total desamide form, dimer and oligomer impurities were estimated to be about 1% by HPLC. Based on the above findings, this raw material was authorized as the Human Insulin Reference Standard of the National Institute of Health Sciences.