Influence of solvent mixtures on HPMCAS-celecoxib microparticles prepared by electrospraying

Hypromellose acetate succinate(HPMCAS) microparticles containing the poorly-water soluble drug celecoxib(CEL) were prepared by electrospraying intended for oral drug delivery. Various solvent mixtures with different solubility for CEL and HPMCAS were used to induce changes in the polymer structural conformation of the microparticles. The performance of the prepared microparticles was evaluated by studying the solid state from, particle size and morphology, radial drug distribution and drug release. CEL was amorphous in all electrosprayed HPMCAS microparticles. The particle size and morphology was dependent on the solubility of HPMCAS in the solvent mixture used with poorer solvents resulting in smaller microparticles with rougher appearance. The CEL distribution on the particles surface was relatively homogeneous and similar for all microparticles. Drug release from the microparticles was observed at a higher rate depending on the solubility of HPMCAS in the solvent used for electrospraying, and in all cases an at least 4-fold higher rate was observed compared with the crystalline drug. Drug precipitation from the supersaturated solution was inhibited by HPMCAS for all microparticles based on its parachute effect while crystalline CEL did not reach supersaturation. This study demonstrated that electrospraying can be used to produce microparticles with tailored properties for pharmaceutical application by adjusting solvent selection.

布地奈德缓释干粉吸入剂的制备及乳糖用量的影响

采用高压匀质联合喷雾干燥法制备载有布地奈德的壳聚糖微粒并考察其体外释放行为,用涡旋混合器使之与乳糖混合,以药物回收率和含量均匀度为指标考察混合速度与混合时间的影响,以药物回收率、含量均匀度、粉末流动性和体外沉积分布为指标考察乳糖用量的影响。制得微粒具有一定的体外缓释效果,可吸入组分百分比为46.0%,但流动性较差,加入10倍乳糖进行混合后,药物回收率高达96.5%,药物含量的相对标准偏差为2.5%,流动性较好,可吸入组分百分比提高至59.6%。结果表明,采用涡旋混合器可制备回收率及含量均匀度均较高的布地奈德缓释干粉吸入剂,处方具有较好的流动性,适于肺部吸入。