POLOXAMER-COATED 3-PLY-WALLED MICROCAPSULES FOR CONTROLLED DELIVERY OF DICLOFENAC SODIUM

The three-ply-walled-based system for controlled delivery of diclofena c was developed. The preparation of three-ply-walled microcapsules is essentially based on the technique of multiple-emulsion formation poly mer at the interface followed by rigidization of the wall on evaporati on of solvent. The protective colloids with surface-active properties were selected for the present study, viz. acacia gelatin, polyvinyl al cohol and sodium alginate. Ethyl cellulose was taken as hydrophobic po lymer. The acacia/ethylcellulose/acacia-based three-ply-walled microca psule system was selected for further studies. The three-ply-walled mi crocapsule were subsequently coated with poloxamer 188. The non-ionic hydrophilic surfactant coating retards uptake into the reticuloendothe lial system. The coated and uncoated microcapsules were characterized for in vitro and in vivo performance. The microcapsules were noted to provide sustained release of the contained diclofenac. The plasma leve l observed indicated that poloxamer coating results in prolonged relea se of the drug. Organ distribution demonstrated a different distributi on pattern when compared with uncoated microcapsules.