Preparation and characterization of Metaxalone nanoparticles prepared by High Pressure Homogenization.

The aim of present work was to enhance the dissolution of poorly soluble drug metaxalone  by particle size reduction. Metaxalone nanoparticles are obtained by high pressure homogenization followed by drying, which are characterized for mean particle size (MPS), polydispersity-index(PDI), zeta-potential(ZP), X-ray diffraction(XRD), Differential scanning calorimetry(DSC), Fourier-transform infra-red(FTIR), scanning electron microscopy (SEM), flow properties, saturation solubility and in-vitro release. The MPS of nanoparticles was observed to be less than 200 nm. The negative ZP indicates the stable nanoparticles obtained by sufficient adsorption of the stabilizers onto drug surface. The XRD and DSC  show the retention of drug crystallinity. Out of three drying methods,  SD and SG have obtained stable nanoparticles with improved flow properties. Nanoparticles increased the drug solubility by approximately 4 folds with Hydroxy propyl methyl cellulose and sodium lauryl sulfate as surface stabilizers. In-vitro release studies showed a remarkable increase in rate of drug release from 3 % (pure drug) to 34-36 % (nanoparticles) after 15 minutes and at the end of dissolution study almost 95 % of drug dissolved when compared to only 30 % of pure drug. The combining methods of HPH followed by SD/SG was observed to be promising method to produce stable nanoparticles of metaxalone with remarkable increase dissolution rate.. Results from this study suggest that these metaxalone nanoparticles may be a potential candidate for oral administration with quick onset of action for relief of acute painful musculoskeletal conditions.