Abstract

Piroxicam, a nonsteroidal antiinflammatory agent, is widely used as a first line drug in the symptomatic relief of rheumatoid arthritis and osteoarthritis. One of the major problems with this drug is its very low solubility in biological fluids, which results into poor bioavailability after oral administration. Therefore, solid dispersions of piroxicam with polyethylene glycol 400 and polyvinyl pyrolidone K-30 were prepared to increase its water solubility. Solid dispersions of piroxicarn were prepared using polyethylene glycol 400 as a water soluble carrier (1:4, 1:8, 1:12, 1:16, 1:20 by weight) employing solvent evaporation method. The drug release profile was studied according to USP XXlll monograph in simulated gastric fluid. Piroxicam was released at a much higher rate from solid dispersions containing polyethylene glycol 400 and physical mixture as compared to that of pure drug powder. Faster dissolution rate was observed in 1:12 drug:carrier ratio. Physical mixture of piroxicam and polyethylene glycol 400 in a same ratio released the drug at a slower rate as compared to that of solid dispersions. Solid dispersions of piroxicam were also prepared using PVP K-30 as a water-soluble carrier (1:1, 1:2, 1:3, 1:4 and 1:5 by weight) employing solvent evaporation method. Piroxicam was released at a much higher rate from solid dispersion and physical mixture as compared to that of pure drug powder. Faster dissolution was exhibited by solid dispersion containing 1:4 ratio of drug: PVP compared to physical mixture and pure drug. The increase in dissolution rate of the drug may be due to increase of wettability, hydrophilic nature of carrier and also possibly due to reduction in drug crystalinity.