In vivo and in vitro study of transdermal application of diclofenac sodium using nonionic microemulsions as colloidal drug delivery systems

Nonionic microemulsions (MEs) were used in the present study as carriers for diclofenac sodium (DS) in attempt to evaluate their transdermal application. Span 20 and Tween 80 were selected as surfactants and cosurfactants where isopropyl myristate was selected as lipophilic phase. DS was dissolved in a mixture of water and dimethyl sulfoxide (DMSO) as a hydrophilic phase. The flux of formulated DS in MEs was estimated using Franz diffusion cell through shaved rat's skin for increased hydrophilic phase portion, increased DS content and different surfactants combination. Moreover, pseudo ternary diagrams were constructed and the droplets sizes were evaluated using zeta-sizer. Also, the rheological properties were determined. The MEs complied with colloidal characteristics regarding their droplets size, rheological properties and transparency. Two formulations from tested formulations which exhibited the highest flux values (278 and 437 mu g/h*cm(2)) were chosen for further in vivo bioavailability study in rats. The in vivo results for these two systems showed maximum concentration of 2.43 and 0.94 mg/ml after 4.14 and 4.19 h respectively. Hence, the developed systems offered good transdermal ability through rat's skin for DS. It is recommended for further study to subject the two delivery systems for testing using human skin. (c) 2017 Elsevier B.V. All rights reserved.