Preparation of cyclosporin A polylactic acid microsphere for topical application / 医学研究生学报

ABSTRACT

Objective:To prepare the cyclosporin A(CsA) polylactic acid microspheres using solvent evaporation method from an oil-in-water system.Methods:Orthogonal experiment was used to optimize the method of CsA polylactic acid microspheres preparation.The microspheres were characterized for drug loading and entrapment efficiency by high-performance liquid chromatography(HPLC),average size by particle size analyser and surface morphology by scanning electron microscopy(SEM).In vitro the release kinetics were studied using a modified dialysis method.Results:SEM studies showed discrete and spherical particles with smooth surfaces.The average particle size was 18.234 ?m,with more than 80% of the microspheres falling in the range of 9.525-32.400 ?m.The drug loadings ranging was(34.51?0.63)% with a high encapsulation efficiency(86.12?0.77)% determined by HPLC.In vitro release study revealed a profile of sustained release of CsA from CsA-PLA-MS.The accumulated release percentage of CsA microspheres were 40.8% in 30 d.CsA release profiles show CsA release could be divided by two different phases,fast release within the first few days and the subsequent sustained release.Conclusion:CsA polylactic acid microspheres have been successfully prepared and sustained release of CsA from microspheres have been achieved.