Preparation and characterization of naproxen loaded lipid microsphere by melt solidification technique
Vikrant Nikam, Sanjay Jain
The present study envisages formulation of wax microparticulate drug delivery system. Naproxen, a well-known non-steroidal anti-inflammatory drug was encapsulated with waxy polymers to provide sustained action and to minimize gastro esophageal side effects by avoiding the Release of drug in the upper gastrointestinal tract. Congealable disperse encapsulation method using biodegradable waxes such as beeswax, ceresin wax microspheres using a wetting agent was the method of choice. The formulations were prepared by keeping the amount of drug fixed to 250mg and the total amount of lipids bees wax and ceresin wax were used in varying concentration. Solid, discrete, reproducible free flowing microspheres were obtained. These microspheres have free flowing and good packing properties and shows the characterization values well within the limit that are angle of repose, % Carr’s index and tapped density. In-vitro drug release was studied in a paddle type dissolution Apparatus for hours in phosphate buffer having ph 7.4. After 24 hours, the release of drug was 89.86% for F6 which contains beeswax. The release mechanisms were explored and explained with zero order, first order, Higuchi and korsmeyer-peppas models. Microspheres surface Morphological study was done by scanning electron microscopy (SEM). Drug polymer incompatibility studies were Performed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The Absence of endothermic melting peak of naproxen in DSC thermogram revealed that the drug might be dispersed in the polymer as solid solution or in a metastable molecular dispersion. The drug loaded in microspheres was found to be stable and compatible with waxes as confirmed by FTIR studies.