Abstract
A transdermal therapeutic system (TTS) of diclofenac diethylamine (DDE) was developed to obtain a prolonged controlled drug delivery by the solvent evaporation technique. The matrix diffusion controlled systems used various combinations of hydrophilic (polyvinylpyrrolidone K30) and lipophilic (Eudragit RL 100 (R) and Eudragit RS 100 (R)) polymers containing dimethyl sulfoxide (DMSO) (0, 5 and 10% w/w) as a penetration enhancer. In vitro drug release was improved with an increased fraction of hydrophilic polymer. Formulation F8 containing Eudragit RL 100 (R) and polyvinylpyrrolidone K30 in the ratio 40: 60 presented the highest drug release (92.45%) and permeation rate (0.0988 +/- 0.010 mg/cm(2)/h) with sustained release action for 48 h. In vivo pharmacodynamic study of DDE-loaded Eudragit RL 100 (R) transdermal system (formulation F8) showed significant higher percent inhibition of rat paw edema compared with the marketed formulation of the drug. Our results suggest that a developed formulation is an efficient system for transdermal diclofenac delivery against inflammation. The optimized formulation was found to be stable and did not show physicochemical interaction. The system is envisaged to be stable for a sufficiently long period (2.52 years) at room temperature.