An Investigation on Physicochemical Properties of Piroxicam Liquisolid Compacts

The potential of liquisolid systems to improve the dissolution properties of water-insoluble agent (piroxicam) was investigated. In this study, physicochemical properties of piroxicam liquisolid tablets, effect of aging and type of the carrier was also investigated. To this end, several liquisolid tablets formulations containing various ratios of drug: solvent and different carriers were prepared. X-ray crystallography, differential scanning calorimetry (DSC) and contact angle measurement were used for evaluation of physicochemical properties of piroxicam. Liquisolid compacts exhibited significantly higher drug dissolution rates, in different dissolution media, compared to compacts prepared by the direct compression technique. The results showed that enhanced dissolution rate of piroxicam liquisolid tablets was due to an increase in wetting properties and surface area of drug available for dissolution. In order to investigate the effect of aging on the hardness and dissolution rate of liquisolid compacts, the cformulations were stored at 25oC/75% relative humidity for a period of 9 months. The results showed that aging had no significant effect on hardness or dissolution profile of liquisolid tablets. It was shown that Avicel had more liquid retention potential in comparison with other carriers, but there were no significant differences in the dissolution profiles between formulations. The results of DSC and X-ray crystallography did not show any changes in crystallinity of the drug and interaction between piroxicam and exipients (Avicel and silica) during the process.