Physicochemical investigations of dipolar aprotic solvents as potential cholelitholytic agents

Abstract

Abstract A number of dipolar aprotic solvents have been examined as potential co-solvents for gallstone dissolution. The power of these agents to solubilize such gallstone components as cholesterol, calcium carbonate, calcium palmi-tate and palmitic acid was determined and compared with that of monooctanoin (Capmul), using the synthetic solubility method. The solubilities of cholesterol and palmitic acid were greater in the N-methyl, N-ethyl and N-butyl-pyrrolidone derivatives than in monooctanoin. In contrast, the solubilities of the calcium salts were very low (<0ṁ25% w/w) in all solvents examined. The influence of N-methylpyrrolidone (NMP) on both the in-vitro dissolution of cholesterol from gallstones and the decrease in stone weight with time was determined. NMP proved to be a better solvent than monooctanoin for human stones. NMP, which is miscible with water and monooctanoin, may have potential as a co-solvent in the design of solvent systems for gallstones.