Enhanced dissolution of gallstone by combining ethanol with two commonly used cholelitholytic solvents

Contact dissolution therapy is one of the non-surgical treatments for patients with gallstone. Among the various solvents, methyl tert-butyl ether (MTBE) is used for cholesterol gallstone, while tetrasodium ethyl-dimethyl tetraacetate (EDTA-4Na) solution is used to dissolve calcium bilirubinate stones. However, the contents of gallstone cannot be precisely predicted while they are still present in the human body. This study was designed to test if the MTBE and EDTA can be mixed together and to test the solubility of different kinds of gallstone in each original solution and mixture.

Each 0.1 gm of mixed cholesterol stone, brown stone and pigment stone from 18 patients was used. Pure ethanol was chosen to enhance the miscibility between the organic phase of MTBE and the aqueous phase of EDTA. The contents of gallstone after dissolution were examined with scanning electromicroscopy.

We found the mixture of ethanol, MTBE and EDTA to be the most efficient solvent in gallstone dissolution in comparison with the other two original solvents. The mixture reached a dissolution percentage of 97.96 +/- 1.00, 88.96 +/- 6.51 and 67.75 +/- 14.26 for cholesterol, brown and black pigment gallstone, respectively.

We concluded that ethanol can be used to mix the MTBE and EDTA with good preservation in their litholytic effects on gallstone. The ethanol-MTBE-EDTA solvent is, therefore, a promising universal cholelitholytic agent which deserves further tests for its safety and efficacy in the in vivo study.