بررسی پایداری فیزیکی حالت جامد و سازگاری پیروکسیکام با مواد جانبی قرص‌ها توسط روش‌های فیزیکوشیمیایی

Background and purpose: The pharmaceutical excipients can be incompatible with drug or other excipients. Thus, for each material, compatibility with formulation components and packaging materials should be examined. The dissolution of a drug has an important role in its bioavailability. Any change in the physico-chemical properties can result in changes in the drug release, and furthermore in its bioavailability. In order to overcome such changes, it is necessary to determine the storage conditions required for obtaining a desired drug release. The aim of this study was to investigate the effects of time and environmental factors on the physical properties of piroxicam tablets. Materials and methods: Piroxicam tablets were prepared by the direct compression method and using different excipients. After conducting some initial tests, these tablets were subjected in different temperatures and humidities for six months. Drug release and disintegration time were analyzed in periods of study (baseline, 3, and 6 months). DSC (differential scanning calorimeter) and FTIR (fourier transform infrared) were used to determine the possible interactions between drug and excipients. Results: The results of drug release from different formulations after 3 and 6 months storage in 25° C /60% RH and 40° C /75% RH showed statistically significant difference among various times. Under all storage conditions piroxicam tablets showed an increase in disintegration time. DSC and FTIR did not show any interaction between formulation ingredients. Conclusion: The results of dissolution and disintegration time showed that keeping piroxicam tablets for three and six months in different conditions caused significant changes in the drug release and disintegration time. Moreover, no change was observed in the physical stability of tablets.