Development and evaluation of transdermal patches of celecoxib

Low-dose, matrix-type transdermal patches containing celecoxib were developed for the treatment of osteoarthritis. The patches were designed to be used over a period of 24 h. Different ratios of ethyl cellulose/polyvinyl pyrrollidone (EC/PVP) were used for the development of the system. All of the prepared patches were subjected to physicochemical evaluation, in vitro drug release, permeation, and anti-inflammatory studies (in vivo). The release rates and flux increased linearly when an increase in the fraction of PVP was mixed with the formulations. In vitro studies showed enhanced performance in the presence of an enhancer (5% v/v oleic acid). The cumulative amount of drug permeated was found to be proportional to the square root of time (following the Higuchi equation). The anti-inflammatory effect (in vivo) and sustained action were studied by a carrageenan-induced (1% w/v) rat hind paw edema method. The selected formulation (EC/PVP, 2:3) produced 100% inhibition of paw edema in rats up to 6 h after receiving the carrageenan injection. The inhibition was 94.42%, 89.77%, and 86.44% after 8, 12 and 24 h, respectively. From this study it can be concluded that celecoxib can be formulated into a patch for transdermal delivery. Therefore, celecoxib can be recommended for further pharmacokinetic and pharmacodynamic studies in suitable animal models.