目的制备尼莫地平(NMP)/介孔二氧化硅纳米固体分散体,以期通过提高尼莫地平的溶出速率,改善尼莫地平的生物利用度。方法采用软模板法分别制备2种介孔二氧化硅SBA-16和SBA-15,对其进行表征,采用熔融法和溶剂法分别制备尼莫地平/二氧化硅固体分散体,以氮吸附曲线,扫描电镜,X-射线衍射及差示扫描量热法对载药与载药体系进行表征,并对自制固体分散体的溶出速率与大鼠体内药动学进行研究。结果SBA-16为规则的球形形貌,比表面积为775.8m2·g-1,总孔体积为0.7cm3·g-1。SBA.15为棒状结构,比表面积为449.1m2·g-1,总孔体积为1.02cm2·g-1;当载体与药物的投料比为3:1以上时.药物以非晶型形式吸附于载体表面及载体孔道中;自制固体分散体给予大鼠ig后与进口市售制剂尼膜同相比.溶出度与生物利用度均有所提高。结论介孔二氧化硅适用于尼莫地平纳米固体分散体的制备,所制纳米粒具有提高生物利用度的作用。
OBJECTIVE To prepare solid dispersion of mesoporous silica- nimodipine (NMP) in hope of improving its dissolution rate and bioavailability. METHODS Two kinds of mesoporous silica, SBA-16 and SBA-15, were prepared by soft template method and characterized. Melting method and solvent method were carried out to prepare two kinds of NMP/mesoporous solid dispersions. Nitrogen sorption, SEM, X-ray and DSC were carried out to characterize the NMP/mesoporous solid dispersions. The tablets were prepared and the dissolution rate was determined. The bioavailability of NMP/mesoporous silica was evaluated in rats. RESULTS SBA-16 had regular spherical-like morphology. The specific surface area and total pore volume of SBA-16 were 775. 8 m2 ~ g-land 0. 7 cm3 ~ g-l, respective- ly. And 2D hexagonal SBA-15 with the morphology of rod-like structure with long channels was successfully prepared and the specific sur- face area and total pore volume of SBA-15 were 449. 1 m2 ~ g -1 and 1.02 cm3 ~ g -1, respectively. The drug in the carrier was in the form of microcrystal or amorphous when the drug/carrier ratio was above 3: 1. Compared with nimotop, the prepared tablets of mesoporous sili- ca-nimodipine had an increased dissolution rate and an improved bioavailability. CONCLUSION The prepared mesoporous silica is suitable for the preparation of NMP/mesoporous solid dispersion which obtains an improved bioavailability.