In vitro evaluation of transdermal patches of flurbiprofen with ethyl cellulose.

This study was aimed to determine effects of penetration enhancers and plasticizers on drug release from rationally designed formulations of flurbiprofen based transdermal drug delivery system. Matrix type transdermal patches were formulated with ethyl cellulose (EC) as a polymer by using plate casting method. The plasticizers such as propylene glycol (PG) and dibutyl phthalate (DBP), and enhancers such as Span 20, Tween 20, sodium lauryl sulfate (SLS), isopropyl myristate (IPM) and ethanol (EtOH) were formulated in different concentrations in the patches. Such different combinations of polymer with various enhancers and plasticizers in patches were evaluated for their effect on the physicochemical properties and drug release behavior of flurbiprofen. The drug release study was carried out by the paddle-over-disk method and permeation of drug was performed by Franz diffusion cell using rabbit skin. Patches having ethanol with ethyl cellulose showed more uniformity in the physical properties while the smoothness and clarity of patches containing sodium lauryl sulfate were not satisfactory. The drug release from patches followed Higuchi and Korsmeyer-Pappas model while maximum drug release was obtained by isopropyl myristate (903 microg). It was concluded that the patches having ethyl cellulose with isopropyl myristate and propylene glycol are more useful for transdermal patches of flurbiprofen.