Use of an in vitro haemolysis test to predict tissue irritancy in an intramuscular formulation

As part of a drug development program, an in vitro haemolysis test has been used to predict the in vivo muscle tissue irritancy of intramuscular (i.m.) formulations of a new drug entity. Solutions of lactic acid, polyvinylpyrrolidone (PVP) 12PF and two commercial injections were also included in the study. The results indicated that the test was able to differentiate formulations in terms of haemolytic potential and the correlation between the haemolysis test results and in vivo intramuscular irritancy studies indicated that the test may be used to screen formulations for potential tissue irritancy prior to in vivo evaluation.