A NEW PHYSIOLOGICALLY APPROACHED IN-VITRO TEST FOR QUICK EVALUATION OF THE HEMOLYTIC-ACTIVITY OF SURFACTANTS

New physiologically approached in vitro assays are presented which all ow rather quick and uncomplicated determinations of the hemolytic acti vity of surfactants, intended mainly to solubilize poorly soluble drug s in parenteral dosage forms. The extent and the rates of the hemoglob in release from erythrocytes during the incubation of blood with incre asing additions of surfactants is thought to be a very suitable and re alistic estimation of the membrane damaging side effects of amphiphili c substances. In this study the extent of free hemoglobin released int o the plasma is determined by a spectrophotometric method, as well as by an enzymatic determination measuring the lactate dehydrogenase (LDH ) activity. LDH is released in a similar way from damaged erythrocytes . The results of these two methods are compared. They correspond satis factorily.