Weerapol Yotsanan, Limmatvapirat Sontaya, Nunthanid Jurairat, Konthong Srisuda, Suttiruengwong Supakij, Sriamornsak Pornsak
Pharmaceutical Biopolymer Group (PBiG), Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand.
Faculty of Pharmaceutical Sciences, Burapha University, Chonburi 20131, Thailand.
Asian J Pharm Sci. 2017 Jul;12(4):335-343. doi: 10.1016/j.ajps.2017.01.002. Epub 2017 Jan 18.
Solid dispersions of nifedipine (NDP), a poorly water-soluble drug, and amino methacrylate copolymer (AMCP) with aid of adsorbent, that is, fumed silica, talcum, calcium carbonate, titanium dioxide, and mesoporous silica from rice husks (SRH), were prepared by solvent method. The physicochemical properties of solid dispersions, compared to their physical mixtures, were determined using powder X-ray diffractometry (PXRD) and differential scanning calorimetry (DSC). The surface morphology of the prepared solid dispersions was examined by scanning electron microscopy (SEM). The dissolution of NDP from solid dispersions was compared to NDP powders. The effect of adsorbent type on NDP dissolution was also examined. The dissolution of NDP increased with the ratio of NDP:AMCP:adsorbent of 1:4:1 when compared to the other formulations. As indicated from PXRD patterns, DSC thermograms and SEM images, NDP was molecularly dispersed within polymer carrier or in an amorphous form, which confirmed the better dissolution of solid dispersions. Solid dispersions containing SRH provided the highest NDP dissolution, due to a porous nature of SRH, allowing dissolved drug to fill in the pores and consequently dissolve in the medium. The results suggested that solid dispersions containing adsorbents (SRH in particular) demonstrated improved dissolution of poorly water-soluble drug when compared to NDP powder.
采用溶剂法制备了难溶性药物硝苯地平（NDP）与氨基甲基丙烯酸酯共聚物（AMCP）的固体分散体，并借助吸附剂，即气相二氧化硅、滑石粉、碳酸钙、二氧化钛和稻壳介孔二氧化硅（SRH）。通过粉末X射线衍射（PXRD）和差示扫描量热法（DSC）测定了固体分散体与其物理混合物相比的物理化学性质。通过扫描电子显微镜（SEM）检查制备的固体分散体的表面形态。将NDP从固体分散体中的溶出度与NDP粉末进行比较。还研究了吸附剂类型对NDP溶出度的影响。与其他制剂相比，当NDP:AMCP:吸附剂的比例为1:4:1时，NDP的溶出度增加。从PXRD图谱、DSC热谱图和SEM图像可以看出，NDP以分子形式分散在聚合物载体中或以无定形形式存在，这证实了固体分散体具有更好的溶出度。含有SRH的固体分散体具有最高的NDP溶出度，这是由于SRH的多孔性质，使得溶解的药物能够填充到孔隙中并因此溶解在介质中。结果表明，与NDP粉末相比，含有吸附剂（特别是SRH）的固体分散体显示出难溶性药物溶出度的提高。
