Development and characterization of pentoxifylline cocrystals: the crystal engineering approach improving pharmaceutical properties

The study of intermolecular interactions and their effects on crystalline packing has made possible the development of crystalline structures with desired properties, which leads to an emerging interest in the pharmaceutical cocrystals1,2. Pentoxifylline (PTX) is a drug commonly used in symptoms of peripheral arterial disease and intermittent claudication3. Crystal engineering was applied to obtain PTX cocrystals targeting the optimization of pharmaceutical properties. X-ray diffraction, thermal analysis and vibrational spectroscopic were used as characterization methods. A polymorph and cocrystal screening based on 16 solvents and 25 coformers by using Liquid Assisted Grinding, have produced 13 cocrystals (ex. Figure 1), from which 6 were previously reported. Thermal analysis shows that the cocrystal with higher melting point was PTX:GAL, whereas and the lower one was PTX:GLT. Parallel to these results, it was possible to find a new polymorphic form of PTX. As future perspectives, solubility, flowability and density tests will be performed.