Hu Fu-Qiang, Jiang Sai-Ping, Du Yong-Zhong, Yuan Hong, Ye Yi-Qing, Zeng Su
School of Pharmaceutical Science, Zhejiang University, 353 Yanan Road, Hangzhou 310031, PR China.
Int J Pharm. 2006 May 11;314(1):83-9. doi: 10.1016/j.ijpharm.2006.01.040. Epub 2006 Mar 24.
Nanostuctured lipid carriers (NLC) consisted of solid lipid and liquid lipid are a new type of lipid nanoparticles, which offer the advantage of improved drug loading capacity and release properties. In this study, solvent diffusion method was employed to produce NLC. Monostearin (MS) and caprylic/capric triglycerides (CT) were chosen as the solid lipid and liquid lipid. Clobetasol propionate used as a model drug was incorporated into the NLC. The influences of preparation temperature and CT content on physicochemical properties of the NLC were characterized. As a result, monostearin solid lipid nanoparticles (without CT content, SLN) obtained at higher temperature (70 degrees C) exhibited slightly higher drug loading capacity than that of 0 degrees C (P < 0.05). In contrast, the production temperature made little effect on NLC drug loading capacity (P > 0.05). The improved drug loading capacity was observed for NLC and it enhanced with increasing the CT content in NLC. The results were explained by differential scanning calorimetry (DSC) measurement for NLC. The incorporation of CT to NLC led to crystal order disturbance and thus left more space to accommodate drug molecules. NLC displayed a good ability to reduce the drug expulsion in storage compared to SLN. The in vitro release behaviors of NLC were dependent on the production temperature and CT content. NLC obtained at 70 degrees C exhibited biphasic drug release pattern with burst release at the initial 8h and prolonged release afterwards, whereas NLC obtained at 0 degrees C showed basically sustained drug release throughout the release time. The drug release rates were increased with increasing the CT content. These results indicated that the NLC produced by solvent diffusion method could potentially be exploited as a carrier with improved drug loading capacity and controlled drug release.
由固体脂质和液体脂质组成的纳米结构脂质载体（NLC）是一种新型脂质纳米颗粒，具有提高药物负载能力和释放特性的优势。本研究采用溶剂扩散法制备NLC。选用单硬脂酸甘油酯（MS）和辛酸/癸酸甘油三酯（CT）作为固体脂质和液体脂质。将丙酸氯倍他索用作模型药物载入NLC中。表征了制备温度和CT含量对NLC物理化学性质的影响。结果显示，在较高温度（70℃）下获得的单硬脂酸甘油酯固体脂质纳米颗粒（不含CT成分，SLN）的药物负载能力略高于0℃时的负载能力（P<0.05）。相比之下，生产温度对NLC的药物负载能力影响不大（P>0.05）。观察到NLC的药物负载能力有所提高，并且随着NLC中CT含量的增加而增强。通过对NLC的差示扫描量热法（DSC）测量对结果进行了解释。CT掺入NLC导致晶体有序性紊乱，从而留出更多空间来容纳药物分子。与SLN相比，NLC在储存时显示出良好的减少药物排出的能力。NLC的体外释放行为取决于生产温度和CT含量。在70℃下获得的NLC表现出双相药物释放模式，在最初8小时有突释，随后是缓释，而在0℃下获得的NLC在整个释放时间内基本呈现持续药物释放。药物释放速率随着CT含量的增加而增加。这些结果表明，通过溶剂扩散法制备的NLC有可能被开发为具有提高的药物负载能力和可控药物释放的载体。
