Improving Dissolution of Meloxicam Using Solid Dispersions

Meloxicam is a poorly water soluble non steroidal anti-inflammatory drug and antipyretic agent. The aim of the present work was to investigate the effect of different types of carriers on in vitro dissolution of meloxicam. Meloxicam solid dispersions were prepared by physical mixing, co-grinding and solvent evaporation methods with polyethylene glycol (PEG) 6000. The effect of solubilization by sodium lauryl sulphate (SLS) was also studied. The dissolution was determined by USP XXVII Apparatus I, using phosphate buffer with a pH of 7.4 as the dissolution medium. The maximum in vitro dissolution of meloxicam, i.e. 97.45% in 60 min, was observed for solid dispersions containing meloxicam (150 mg), PEG 6000 (350 mg) and SLS (75 mg) prepared by solvent evaporation method containing a sum of 3 g of Lactose and MCC (4:1) as additives. The general trend indicated that there was an increase in dissolution rate for solid dispersions containing the solubilizer SLS. The best-fit model indicating the mechanism of dissolution from the formulation showing the highest release for was found to be Higuchi matrix release (r=0.9774, b=13.042, a=2.4798). Infra red spectroscopy (IR) indicated that meloxicam in solid dispersions showed physical entrapment. The increased in dissolution rate of meloxicam by solid dispersion technique may be due to increase wettability and hydrophilic nature of carrier.