Thermal and dissolution studies of Cefpodoxime proxetil drug and tablets

摘要

Cefpodoxime proxetil is commonly used antibacterial drug. Thermal analysis and dissolution studies are routinely conducted by pharmaceutical industries in order to evaluate the drug stability, the drugexcipient interaction and compatibility. In this study dynamic thermogravimetry (TG) experiments were performed in flowing dry air atmosphere (20 ml min-1) to investigate the thermal decomposition of cefpodoxime proxetil drug and tablets (A, B and C) containing different excipients. The TG curve of cefpodoxime proxetil drug shows single decomposition process while tablets (A, B and C) display two. Decomposition activation energies and thermal rate constant (kT) were determined using model-free methods viz. Kissinger, Friedman, Flynn-Wall-Ozawa, and modified Coats-Redfern. The dissolution study of samples was carried out in accordance of United State Pharmacopeia (USP 32) and Kitazawa equation was used for kinetics. Samples are found to have following sequence of the thermal stability: tablet B cefpodoxime proxetil drug tablet A tablet C and the dissolution order: tablet B cefpodoxime proxetil drug tablet A tablet C. The thermal rate constant (kT) and dissolution rate constant (kD) were also correlated graphically and found to have very good correlation with regression coefficient close to 1.