EVALUATION OF PHARMACOKINETIC PARAMETERS OF SOLID DISPERSIONS OF PIROXICAM

Dissolution rate and dissolution efficiency of poorly soluble non-steroidal anti-inflammatory drugs(NSAIDs) could be markedly enhanced by solid dispersion technologies. Solid dispersions ofpiroxicam (PRX) are subjected to in vivo pharmacokinetic evaluation to evaluate whether these systems improve oral bioavailability of the piroxicam. All the pharmacokinetic parameters of absorption, namely Ka, Cmax, Tmax, percent absorbed to various times and AUC indicated rapid absorption and higher bioavailability of piroxicam when administered as solid dispersion. The absorption rate constant (Ka) was found to be 1.56 hr-1 in the case of piroxicam-CC-PVP soliddispersion. Where as in the case of piroxicam Ka was only 0.87 hr-1. An increase of 2.16 fold in Ka was observed with piroxicam-Croscarmellose-Polyvenyl pyrollidine (PRX-CC-PVP) solid dispersion. AUC (extent of absorption) was also much higher in the case of piroxicam solid dispersion when compared to piroxicam. [AUC]0-12h was increased from 55.58 μg-hr/ml for piroxicam to 56.21 μg-hr/ml for piroxicam solid dispersion . Both Ka and AUC were markedlyincreased by solid dispersion. Thus, the results of pharmacokinetic studies indicated rapid and higher oral absorption of piroxicam when administered as CC-PVP solid dispersion.