[Ulinastatin reference standard (Control 941) of the National Insutitute of Health Sciences].

The raw material of ulinastatin was examined for preparation of the "Ulinastatin Reference standard". The candidate material was evaluated in collaboration with one domestic laboratory, and the potency of trypsin inhibiting activity was determined to be 3500 unit/vial. Other analytical data obtained were as follows: UV maximum absorption was observed at 276 nm, the molecular weight was estimated to be about 66000 +/- 5000 by gel filtration method. Maximum variance of material contents in 10 vials was 6.52% by means of the weight variation test in JP XII. Based on the above results, this raw material was authorized to be the first "Ulinastatin Reference Standard" of the National Institute of Health Sciences.