Preparation and in vitro release of recombinant antipeptide sustained release microspheres

Purpose To prepare the recombinant peptide(rAHP)poly(L-lactide)(PLA)sustained release microspheres by double emulsion solvent evaporation method.Methods The rAHP-PLA microspheres preparation technique was optimized by orthogonal experiments and in vitro drug release profiles microspheres were also investigated.Results The optimal preparation technique of rAHP-PLA microspheres was:the PLA concentration was 7.5%,the stirring rate of the first emulsion was 900 r/min,the volume ratio of inner water phase to oil phase was 1∶ 10,and the PVA concentration was 5%.The rAHP-PLA microspheres prepared by the optimum technique were smooth,regular in morphology with small span,the encapsulation efficiency was 81.35%,the drug loading was 10.92%,the microsphere yield was 80.26%,and the average particle diameter was in the range of 75-80 μm.The cumulative in vitro release percentage in PBS was 17.5% within 0.5 h,and up to 98.6% in 15 d.Conclusion The rAHP-PLA microspheres can be prepared easily by good morphology with high entrapment efficiency.The in vitro release profiles were in accordance with the guideline of the Pharmacopoeia of China for sustained release preparation.