Effect of production variables on the physicochemical characteristics of celecoxib-loaded stearic and alginic acids-based microparticles.

The objectives of the current investigation were (1) to prepare the microparticles based on stearic and alginic acids from an aqueous system by hot (melt) dispersion method, (2) to achieve a higher drug entrapment efficiency and process yield (%) by changing the production variables such as stirring speed, concentration of stabilizer in aqueous dispersion medium, volume of aqueous dispersion medium, and stirring time, and (3) to see whether or not a retardation in drug release profile was attained from the celecoxib-loaded stearic and alginic acids-based microparticles compared to that of the celecoxib alone. The addition of alginic acid into stearic acid produced spherical-shaped particles with an almost smooth surface. Higher drug entrapment efficiency and process yield (%) values were obtained when the microparticles were prepared at 1000 r/min using 0.1% w/v polyvinyl alcohol in 100 mL aqueous dispersion medium and 30 min stirring time. The in vitro dissolution study in 900 mL of 2% sodium lauryl sulfate (SLS) solution at 75 r/min, however, showed only around 10% retardation in drug release from microparticles compared to the drug release from pure celecoxib alone. This indicated that the gel-like network formed by the alginic acid around the microparticles could not prevent the drug leakage from the microparticles.