Lysis of human red blood cells 1: Effect of contact time on water induced hemolysis.

A dynamic in vitro method for the determination of the degree of hemolysis induced by parenteral formulations is presented. This method utilizes a dual syringe pump apparatus that enables the mixing of a formulation with blood in various ratios and for various contact times. Formulations with varying tonicity were used to test the method. Hemolysis is shown to be directly related to both the hypotonicity of the test solution and the contact time. The proposed method makes it possible to evaluate the hemolytic effects of parenteral formulations at physiologically realistic contact times and formulation:blood ratios.