Design, Formulation and Evaluation of Piroxicam Capsules Prepared by Solid Dispersion Technique

Objective: To improve the dissolution of poorly soluble Piroxicam (PRXM) by solid dispersion technique using water soluble carriers with or without the addition of sodium lauryl sulphate (SLS) as surfactant.
Methods and Materials: Solid dispersions of Piroxicam were prepared using different polymers such as polyethylene glycol (PEG 4000 and PEG 6000) polyvinylpyrrolidone (PVP K30 and PVP K90) without or with addition of 2% of (SLS). Solid dispersions were formulated in drug polymer ratios 1:1, 1:2, and 1:4, each ratio without or with 2% SLS using solvent evaporation method. The prepared formulae were assayed for drug content, production yield and stability properties. Dissolution profiles were done in phosphate buffer pH 7.4 and the in vitro release was evaluated according to the % released after 20, 30, 45 and 60 minutes. An accelerated stability study was done over 3 months at 40o and 60ºC and with relative humidity (RH) 75%.
Results and Discussion: All of the formulated solid dispersions displayed better dissolution profiles as compared to the pure drug. Formulae containing 2% SLS displayed better in vitro release results compared to formulae prepared without SLS. The degradation of PRXM was slow, indicating the chemical stability of PRXM in all prepared formulae.
Conclusion: A formula containing PRXM to PEG 4000 in the ratio 1:1 with 2% SLS was ranked first and gave the best results among prepared formulae.