Solubilizing Properties of Bile Salt Solutions II.

Studies of the influence of inorganic electrolyte on the solubilization of griseofulvin, glutethimide, and hexestrol in four individual bile salt solutions at 37° showed that sodium chloride had little effect on the solubility of the former two drugs but significantly increased the solubility of hexestrol. Based on these findings the possible location of the drug molecules within the micelle is considered. A mixed bile salt system was found to possess a significantly lower critical micelle concentration (CMC) than any of the individual bile salts previously studied. However, the affinities of this mixed micellar system for the drugs were comparable with those obtained with individual bile salts. The addition of lipids to the mixed bile salt system resulted in a decrease in hexestrol solubility but had little effect on griseofulvin and glutethimide solubility. The biological implications of the results obtained in the present communication are explored, and a mechanism for the role of dietary lipids and bile salts in the absorption of drugs is proposed.