Study of Polymorphism on Pargeverine Hydrochloride

Objectives: Screening active pharmaceutical ingredients for polymorphs is of utmost importance in drug development to enable stable APIs, robust manufacturing processes and reduction of costs incurred in switching over crystal forms. The current study deals with exploring polymorphism in Pargeverine Hydrochloride using different solvents and solvent systems. Methods: Drug was crystallized by slow solvent evaporation of filtered saturated solution using either single or mixed solvent systems. The resultant crystals were evaluated for physical appearance and by Fourier- transform Infrared Spectroscopy, Differential Scanning Calorimetry and Powder X-Ray Diffraction. Results: The physical appearance, melting points, pattern of heat flow for phase transition, peak temperature and the IR spectra and Powder X-Ray Diffraction pattern of the crystals of Pargeverine Hydrochloride in single and mixed solvent systems (50 solvent systems) did not show any marked difference from that of pure drug. Conclusion: From the results, it can be concluded that there were minimal possibilities of polymorph formation for Pargeverine HCl in the solvent/s or combination of solvents attempted, thus need for any specific controls to inhibit transition during its routine manufacturing process may not be required.