Studies on the stability of antitumor protein, neocarzinostatin: II. stability of injection of neocarzinostatin

Abstract

In the present study, we have studied the stability of NCS injection for more than two years, the relationship between the antitumor activity against ascites tumor in rat and the antibacterial activity against Sarcina lutea, the drawing of log k-pH profile at 37~38°C, and the stability of NCS with the other injections and drugs. From the results obtained, the storage conditions and the estimation of the term of validity of NCS injection were discussed. (1) No loss in antibacterial activity of NCS injection was observed for two years at below 8°C. (2) The antitumor activity of NCS injection against ascites tumor in rat almost corresponded to the antibacterial activity against Sarcina lutea. (3) Rate constant on pH 5.0 calculated by log k-pH profile at 37~38°C showed a 20-fold stability compared to the rate constant at 55°C. (4) NCS injection was inactivated by reducing reagents such as sodium bisulfide and ascorbic acid, and denaturing reagents such as urea and thiourea, but NCS injection was stable to the other various injections, drugs and reagents. © 1974, Japan Antibiotics Research Association. All rights reserved.