Changez Mohammad, Varshney Manoj, Chander Jadish, Dinda Amit Kumar
Centre for Biomedical Engineering, Indian Institute of Technology, New Delhi 110016, India.
Colloids Surf B Biointerfaces. 2006 Jun 1;50(1):18-25. doi: 10.1016/j.colsurfb.2006.03.018. Epub 2006 Mar 29.
Effect of composition of lecithin water-in-oil and oil-in-water microemulsion on in vitro transdermal permeation of tetracaine hydrochloride was studied on mice model. The results were compared with an aqueous solution of tetracaine hydrochloride (2.7 mg/ml). In vitro skin flux and permeability coefficients were obtained using the Franz diffusion cell. Differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) were used to study the mechanism of action of the microemulsion. Micrographs of TEM and CLSM studies were analyzed by using Image Pro Plus image software. Skin flux of tetracaine hydrochloride was found to be dependent on the composition of lecithin/n-propanol/isopropyl myristate/water microemulsions. At lower Km ratio (i.e. 0.5:1 and 0.8:1) of microemulsion, the rate of permeation of tetracaine hydrochloride was higher when compared to the microemulsion of higher Km ratio (1:1 and 1.5:1). Image analysis of TEM micrograph, 6h after application of lecithin microemulsion, showed 3.5+/-0.75-fold (p<0.001) increase in the intercellular space in the epidermis and 3.8+/-0.4-fold (p<0.001) enhancement in upper dermis. CLMS results show that sweat gland and hair follicles also provided path for permeation of the drug through the skin.
在小鼠模型上研究了卵磷脂油包水和水包油微乳剂的组成对盐酸丁卡因体外透皮渗透的影响。将结果与盐酸丁卡因水溶液（2.7mg/ml）进行比较。使用Franz扩散池获得体外皮肤通量和渗透系数。采用差示扫描量热法（DSC）、透射电子显微镜（TEM）和共聚焦激光扫描显微镜（CLSM）研究微乳剂的作用机制。利用Image Pro Plus图像软件分析TEM和CLSM研究的显微照片。发现盐酸丁卡因的皮肤通量取决于卵磷脂/正丙醇/肉豆蔻酸异丙酯/水微乳剂的组成。在较低Km比（即0.5:1和0.8:1）的微乳剂中，盐酸丁卡因的渗透速率高于较高Km比（1:1和1.5:1）的微乳剂。应用卵磷脂微乳剂6小时后，TEM显微照片的图像分析显示，表皮细胞间空间增加了3.5±0.75倍（p<0.001），真皮上层增强了3.8±0.4倍（p<0.001）。CLMS结果表明，汗腺和毛囊也为药物透过皮肤提供了途径。
