ABSTRACT
OBJECTIVE:To optimize the formulation of azithromycin sustained-release vaginal suppository(ASVS).METHODS:The ASVS was prepared using S-40 as suppository base,HPMC as sustained-release material and glycerine as humectant.The formulation of ASVS was optimized by orthogonal design with accumulated release percentage and hardness as indexes and the amount of 8% HPMC and glycerol as factors;meanwhile,a verification test and the fitting of in vitro drug release model were performed.RESULTS:The optimized formulation ASVS was as follows:azithromycin 6 g,8% HPMC 23.52 g,glycerol 29.40 g,ethanol absolute 3 g,ethylparaben 0.59 g,and S-40 294 g.Three batches of suppositories prepared under the optimized formulation reached a mean content of 99.5%,with hardness up to the standard,showing good reproducibility and homogenicity in drug release in vitro.The accumulative release rates of all samples were greater than 98% at 180 min,and the release dynamics in vitro were in line with Higuchi equations.CONCLUSION:The optimized ASVS is feasible in formulation,stable and reproducible in preparation technology and up to the standard for sustained-release preparation.