ABSTRACT
Aim To study the preparation of α-cobro-toxin-loaded poly ( lactide-co-glycolide ) microspheres and their analgesic effect. Method The microspheres were prepared by modified water-in-oil-in-oil ( w/o/o ) emulsion solvent evaporation method. A tail flick assay was used to evaluate the analgesic activity of the micro-spheres after nasal administration. Result The micro-spheres with high entrapment efficiency ( >80%) and average diameter of about 25 μm could be prepared by modified water-in-oil-in-oil ( w/o/o ) emulsion solvent evaporation method. A tail flick assy showed the evi-dence for their analgesic effect. Conclusion When Chinese cobraneurotoxin is loaded into microsphere and then the microsphere is administered through nasal cav-ity, its analgesic effect is enhanced significantly.