ABSTRACT
Microparticulate systems of aceclofenac were prepared by modified solvent evaporation method using different variables such as polymer [cellulose acetate]: drug ratios [1:9, 1:6, 1:3, and 1:1], agitation speeds [500-1500 rpm] and stirring time [5-15 min]. The effects of processing variables were evaluated by microparticle size and entrapment efficiency. The average microparticle size increases from 80.2 +/- 1.45 to 97.3 +/- 2.06 = m with increase in the polymer concentration while reduces with increase in agitation speed and stirring time; and at the higher speed gives irregular shape of particles. The highest entrapment efficiency, size uniformity, angle of repose [23.6 +/- 0.3 degree] and compressibility index [13.8 +/- 0.7%] of microparticles were found with 1:6 [polymer: drug ratio], at 1000rpm and 10min stirring time among all microparticles. The in-vitro drug release study was carried out with prepared microcapsules [AC-1 to AC-4] of various polymer concentrations and optimized processing variables and compared with conventional and SR tablets. The conventional tablet and SR tablet releases maximum drug within 3 and 6h respectively while microparticulate system releases more than 12h. All formulations followed first order release kinetic and diffusion controlled drug release