COMPATIBILITY AND STABILITY STUDIES OF ANTIHYPERTENSIVE/EXCIPIENTS BY THERMAL METHODS, USED IN THE PREFORMULATION PHASE

The objective of this study was to investigate the quality of the interactions between the active antihypertensive substances and the possible excipients in order to guide the preformulation process of a triple layered tablet. The active substances chosen were Candesartan Cilexetil (CC), Amlodipine Besylate (AB), Hydrochlorothiazide (HCTZ) and the excipients were Croscarmellose sodium (AcDiSol), Magnesium Stearate (StMg), and Colloidal silica (Aerosil). For this purpose we studied the thermal behaviour (differential scanning calorimetry - DSC and thermogravimetry -TG) of CC, AB, HCTZ and the possible excipients Aerosil, AcDiSol, StMg and of the binary mixtures active pharmaceutical ingredient (API) - excipient. The study was performed at To (initial moment) and at different time intervals (1 month, 2 months, 3 months, 6 months and 12 months) under normal temperature and humidity conditions and under accelerated degradation conditions.