[Studies on the quality of enzyme preparations (IX)--kallidinogenase preparations]

Kallidinogenase preparations were investigated with a view of comparing their quality by the enzymological method. These studies were carried out on 13 types of preparations (tablet: 7 kinds, capsule: 3 kinds, ampoule: 3 kinds) of commercially available kalliginogenase preparations. The kinin-liberating activity per one international unit (IU) of kallidinogenase was approximately 400 ng bradykinin/min/IU. The contents of other enzymes, i.e., kininase, trypsin and protease, were determined as the impurities. Kininase, trypsin and protease activities in the preparations for injection were very low. However, one preparation for internal use contained large amounts of these enzyme as impurities. It was presumed that contamination with large amounts of kininase, trypsin and protease have an adverse influence upon the assay and stability and efficacy of these preparations.