HOLLOW MICROSPHERES AS FLOATING DRUG DELIVERY SYSTEMS TO INCREASE THE GASTRIC RETENTION: EFFECT OF COEXCIPIENTS ON FLOATING AND RELEASE CHARACTERISTICS

摘要

Hollow floating microspheres of cellulose acetate (CA) were prepared by a novel solvent diffusion-evaporation method for the controlled release (CR) of nifedipine. The microspheres were found to be floating for > 15 h. The water-soluble plasticizer (polyethylene glycol-400), PEG-400 used as an excipient has decreased the % buoyancy of microspheres, but the water-insoluble plasticizer (dibutyl phthalate), DBP did not affect the buoyancy. For the blend CA + poly(∈ -caprolactone), PCL, microspheres, the % buoyancy decreased with increased PCL concentration. The release of NFD was facilitated by the co-excipients and their concentration.