Development and Characterization of Synergistic Transdermal Patches Containing Zingiber officinale Extract and Diclofenac Sodium for Improved Anti-Inflammatory Action

Research Article

Abstract

A synergistic matrix-type transdermal drug delivery system containing a combination of Zingiber officinale (ginger) rhizome extract and diclofenac sodium was developed to improve therapeutic outcomes in inflammatory disorders while reducing the systemic adverse effects associated with conventional oral non-steroidal anti-inflammatory drugs. Matrix patches were prepared via the solvent casting technique using variable ratios of hydrophilic hydroxypropyl methylcellulose E15 and hydrophobic ethyl cellulose polymers, plasticized with propylene glycol. Physical evaluation of the developed batches showed excellent film uniformity, with thickness values ranging between 0.21±0.01 mm  and 0.31±0.01 mm , and weight variations within acceptable pharmacopoeial limits. The folding endurance exceeded 240 folds across all formulations, indicating substantial mechanical flexibility, which was further substantiated by tensile strength assessments. Biophysical evaluations showed that formulations containing higher hydrophilic polymer proportions exhibited enhanced swelling indices and accelerated in vitro drug release dynamics. In vitro release studies using Franz diffusion cells showed a sustained and controlled drug permeation profile over twenty-four hours, governed predominantly by non-Fickian anomalous diffusion kinetics. In vivo pharmacological tests using carrageenan-induced paw edema and hot plate thermal nociception models in rats showed that the co-delivery of ginger extract and diclofenac sodium yielded a significantly higher inhibition of inflammatory edema and pain sensitivity at lower drug concentrations compared to patches containing the synthetic drug alone. These results confirm the synergistic potential of combining natural phytoconstituents with synthetic analgesics within a transdermal platform to establish an effective, stable, and biocompatible therapeutic system for chronic inflammatory diseases.