Mixed Solvency Concept
In these investigation conventional piroxicam capsule has slow onset of action (45-60 min) and poor bioavailability (50-60%), and therefore cannot be given in emergency clinical situations like postoperative pain, rheumatoid arthritis or osteoarthritis. So purpose of research was to provide a fast dissolving dosage form of piroxicam, which can provide quick onset of action by using mixed solvency concept. First carried out Initially solubility of piroxicam was determined individually in 3 hydrotropic agents like sodium benzoate, sodium citrate, niacinamide and 4 water soluble polymer namely HPBCD, PVP K30, PEG400, PEG8000 at conc. of 40% w/v solutions using purified water as solvent. Highest solubility was obtained in 40% sodium benzoate solution. Then different combinations of 2, 3 and 4 hydrotropic agents+water soluble polymer in different ratios were used to determine solubility, so that total conc. of solubilizer blend was always 40%. Highest solubility was obtained in solution of sodium benzoate+HP-BCD+PVP K30 at optimum ratio of 15:15:10. This optimized combination was utilized in preparing solid dispersions having enhanced solubility & used for pharmaceutical formulations.