INVESTIGATIONS ABOUT HEMOLYSIS AND SOLUBILIZATION BEHAVIOR OF NONIONIC POLYMERIC SURFACTANTS

The solubilization of poorly water soluble drugs in surfactant solutions is still a problem in pharmaceutical technology. There doesn't exist any surfactant which can be applied unrestricted in parenteral dosage forms. For this reason, alkylpolyglycosides and fatty esters of dextran were investigated. Their solubilization behaviour and hemolytic activity was tested and compared to established surfactants. For solubilization, only water soluble surfactants can be used. That means, that only alkylpolyglycosides with two or more glucose units and dextran esters with a degree of substitution of 0.1 or less may be applied. The determination of the CMC of alkylpolyglycosides by solubilization of fluorescent substances shows a plot, typical for monomeric surfactants. The dextran esters show no CMC. They actually are polymeric surfactants and form monomolecular micelles. The differences in hemolytic activity of the alkylpolyglycosides run up to the factor 100. The hemolytic activity increases in this class of surfactants with the elongation of the alkyl chain and decreases with increasing degree of glycosylation. It doesn't exist any correlation between the CMC and the hemolytic activity. For diazepam the differences in solubilization behaviour are rather low. The solubilization behaviour is more effective than that of Solutol(R) HS 15. The hemolytic activity of the dextran fatty esters is low, compared with the alkylpolyglycosides.