Department of Pharmaceutical Sciences, COMSATS Institute of Information Technology, Abbottabad ; Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
Daru. 2011;19(6):433-9.
Microemulsions are thermodynamically stable, clear dispersions of water, oil, surfactant, and cosurfactant. This study was aimed to develop flurbiprofen microemulsion for enhanced transdermal delivery and investigate the effects of different surfactants and cosurfactants on its delivery and phase behavior.
Various surfactant-cosurfactant mixtures in ratio of 2:1 (Smix) along with oleic acid (oil) were selected and phase diagrams were constructed. Six microemulsions each containing 5% drug, 5% oil, 56% Smix and 34% water, were prepared and compared for their permeation and phase behaviors to determine the effects of the type of Smix.
In vitro transdermal permeation through rabbit skin of all microemulsions was high than saturated aqueous drug solution. Tween 20 and ethanol as Smix produced the highest flux amongst all the Smix, and were used to prepare formulations with different values of oil and Smix. While the type of surfactant did not affect the droplet size, propylene glycol as cosurfactant produced the largest droplets and highest viscosity. Decrease in oil or Smix concentration resulted in decrease of the droplet size and increase in permeation flux while decrease in viscosity also increased the permeation flux of microemulsions. Finally the selected microemulsion formulation comprising 5% flurbiprofen, 5% oleic acid, 46% Tween 20:ethanol (2:1) and 44% water, showed the highest transdermal flux and caused no skin irritation.
Type of surfactant and cosurfactant affect both the phase behavior and transdermal drug delivery of microemulsion; and results of this study showed that they are promising vehicles for improved transdermal delivery and sustained action of flurbiprofen.
微乳液是热力学稳定的、水、油、表面活性剂和助表面活性剂的透明分散体。本研究旨在开发用于增强透皮递送的氟比洛芬微乳液，并研究不同表面活性剂和助表面活性剂对其递送和相行为的影响。
选择各种表面活性剂-助表面活性剂混合物（Smix）的比例为 2:1（Smix），并与油酸（油）一起构建相图。制备了包含 5%药物、5%油、56%Smix 和 34%水的 6 种微乳液，分别比较其渗透和相行为，以确定 Smix 类型的影响。
所有微乳液通过兔皮的体外透皮渗透均高于饱和水溶液药物。吐温 20 和乙醇作为 Smix 产生了所有 Smix 中最高的通量，并且用于制备具有不同油和 Smix 值的制剂。虽然表面活性剂的类型不影响液滴大小，但丙二醇作为助表面活性剂产生了最大的液滴和最高的粘度。降低油或 Smix 的浓度会导致液滴尺寸减小，渗透通量增加，而降低粘度也会增加微乳液的渗透通量。最后，选择的微乳液制剂包含 5%氟比洛芬、5%油酸、46%吐温 20:乙醇（2:1）和 44%水，显示出最高的透皮通量，且不会引起皮肤刺激。
表面活性剂和助表面活性剂的类型均影响微乳液的相行为和透皮药物递送；并且本研究结果表明，它们是改善透皮递送和氟比洛芬持续作用的有前途的载体。
