School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Int J Pharm. 2014 Dec 10;476(1-2):169-77. doi: 10.1016/j.ijpharm.2014.09.052. Epub 2014 Oct 1.
Nanostructured lipid carriers and microemulsions effectively deliver poorly water-soluble drugs. However, few studies have investigated their ability and difference in improving drug bioavailability, especially the factors contributed to the difference. Thus, this study was aimed at investigating their efficiency in bioavailability enhancement based on studying two key processes that occur in NLC and ME during traverse along the intestinal tract: the solubilization process and the intestinal permeability process.
The nanostructured lipid carriers and microemulsions had the same composition except that the former were prepared with solid lipids and the latter with liquid lipids; both were evaluated for particle size and zeta potential. Transmission electron microscopy, differential scanning calorimetry, and X-ray diffraction were performed to characterize their properties. Furthermore, in vitro drug release, in situ intestinal absorption, and in vitro lipolysis were studied. The bioavailability of luteolin delivered using nanostructured lipid carriers in rats was compared with that delivered using microemulsions and suspensions.
The in vitro analysis revealed different release mechanisms for luteolin in nanostructured lipid carriers and microemulsions, although the in situ intestinal absorption was similar. The in vitro lipolysis data indicated that digestion speed and extent were higher for microemulsions than for nanostructured lipid carriers, and that more of the former partitioned to the aqueous phase. The in vivo bioavailability analysis in rats indicated that the oral absorption and bioavailability of luteolin delivered using nanostructured lipid carriers and microemulsions were higher than those of luteolin suspensions.
Nanostructured lipid carriers and microemulsions improved luteolin's oral bioavailability in rats. The rapid lipid digestion and much more drug solubilized available for absorption in microemulsions may contribute to better absorption and higher bioavailability.
纳米结构脂质载体和微乳能够有效地递送难溶性药物。然而，很少有研究探讨它们提高药物生物利用度的能力和差异，特别是导致差异的因素。因此，本研究旨在通过研究纳米结构脂质载体和微乳在沿肠道迁移过程中发生的两个关键过程：增溶过程和肠道通透性过程，来研究它们在提高生物利用度方面的效率。
纳米结构脂质载体和微乳的组成相同，只是前者用固体脂质制备，后者用液体脂质制备；两者均进行粒径和zeta 电位评估。采用透射电子显微镜、差示扫描量热法和 X 射线衍射对其性质进行表征。此外，还进行了体外药物释放、原位肠吸收和体外脂肪酶解研究。比较了大鼠用纳米结构脂质载体和微乳递送叶黄素的生物利用度与用混悬剂递送叶黄素的生物利用度。
体外分析表明，尽管原位肠吸收相似，但叶黄素在纳米结构脂质载体和微乳中的释放机制不同。体外脂肪酶解数据表明，微乳的消化速度和程度高于纳米结构脂质载体，并且更多的微乳分配到水相。大鼠体内生物利用度分析表明，大鼠用纳米结构脂质载体和微乳递送叶黄素的口服吸收和生物利用度均高于叶黄素混悬剂。
纳米结构脂质载体和微乳提高了大鼠中叶黄素的口服生物利用度。微乳中快速的脂肪消化和更多可用于吸收的药物增溶可能有助于更好的吸收和更高的生物利用度。
