Molecular salts of propranolol with dicarboxylic acids: diversity of stoichiometry, supramolecular structures and physicochemical properties

Abstract

Crystallization of the drug propranolol with dicarboxylic acids yielded stable crystalline molecular salts with oxalic and fumaric acids in molar ratios of 1 : 1 and 2 : 1, and with maleic acid in a molar ratio of 1 : 1 only. The melting points of the salts obtained were roughly twice the melting point of pure propranolol, while their aqueous solubility was significantly higher in comparison to that of the propranolol base.