DEVELOPMENT AND IN-VITRO EVALUATION OF SUSTAINED-RELEASE MECLOFENAMICACID MICROSPHERES

Meclofenamic acid (MFA) sustained-release microspheres were prepared b y the solvent evaporation method using cellulose propionate (CP) polym er and acetone as the polymer solvent. Polyethylene glycol (PEG) was u sed as a channelling agent to improve the release properties of MFA at 1:2:1 drug to polymer to PEG ratio. The microspheres prepared at thre e different speeds (600, 800 and 1000 rpm) were characterized with reg ard to their surface morphology, average drug content, particle size d istribution and release profiles in phosphate buffer, pH 8.0 at 37 deg rees C. The microspheres were stored under accelerated conditions for 3 months and the effect of storage on the different characteristics wa s studied. Spherical particles with essentially smooth surface and few residual drug crystals on the surface were formed. Smaller particles were formed at higher agitation speeds. The release rate of MFA from t hese microspheres was not affected by the molecular weight of CP polym er. PEG 2000 was found to have a more enhancing effect on the rate of the release than PEG 4000. The physical properties of the microspheres and their release characteristics were not altered by storing the pro duct at 40 degrees C/80% relative humidity (R.H.) for 3 months.