Probing the solid-state behaviour of pharmaceuticals under different environmental conditions

Abstract

The aim of this study is to understand the solid-state properties of imatinib, the free base of imatinib mesylate (Gleevec ®), an active pharmaceutical ingredient (API) that is used to treat chronic myelogenous leukaemia under different environmental conditions using crystal engineering techniques. The behaviour of imatinib after grinding with acidic co-crystal formers was studied, where the API’s solubility was measured in water using UV-Vis techniques. The solubility of imatinib in water improved significantly when ground with acidic co-crystal formers and when ground with pyridoxine. Imatinib free base was recrystallised from several solvents and solvent mixtures, from which one major polymorphic form was detected. The unit cell parameters as well as the atomic co-ordinates were determined. The crystal structure of imatinib free base has been determined but further parameters are still required. Rietveld refinement would be required so that any differences between the experimental powder pattern and modelled crystal data are minimised. This process would validate the structure solution which can eventually be published.