Discovery, characterization, and pharmaceutical applications of two loratadine- oxalic acid cocrystals

Abstract

Crystallization of multi-component crystals is widely used in pharmaceutical science to enhance the physiochemical properties, such as stability, mechanical properties and solubility. Loratadine (Lor) is a BCS II antihistamine drug commonly used to relieve the symptoms of allergy. It has high permeability but low solubility at physiological pHs. To overcome the problem of low solubility, we synthesized and fully characterized two Loratadine multi-component crystalline phases with oxalic acid (Oxa), i.e., a 1:1 Lor-Oxa conjugate acid-base cocrystal (Lor-Oxa CAB) and a 2:1 Lor-Oxa cocrystal monohydrate (Lor-Oxa hydrate). Both cocrystals exhibited adequate physical stability, enhanced solubility and, higher intrinsic dissolution rate than Lor. The intrinsic dissolution rate of Lor-Oxa CAB is 90 times that of Lor, which makes it a promising candidate for tablet formulation development.