[Ulinastatin Reference Standard (Control 971) of the National Institute of Health Sciences]

The "Ulinastatin Reference Standard (control 971)" of National Institute of Health Sciences was prepared. The standard material was evaluated in collaboration with one domestic laboratory, and the potency of trypsin inhibiting activity was determined to be 3, 100 units/vial by relative assay method against the Ulinastatin Reference Standard (control 942). Other analytical data obtained were as follows: UV maximum absorption was observed at 277 nm, and the molecular weight was estimated to be about 66,300 by gel filtration method. Maximum variance of material contents in 10 vials was 2.29%. Based on the above results, this standard material was authorized to be the "Ulinastatin Reference Standard (control 971)" of the National Institute of Health Sciences.