Studies on Hydrogel-Based Diclofenac Epolamine Topical Patch in Comparison with Flector® Patch

Diclofenac sodium is a well-known nonsteroidal anti-inflammatory drug (NSAIDs) that is commonly used to treat musculoskeletal problems, toothaches, arthritis, and dysmenorrhoea, as well as to provide symptomatic pain and inflammation relief. However, oral administration of these therapeutic drugs has a number of side effects that can be avoided by using a topical drug delivery system. Diclofenac epolamine is a newer salt with a cyclic salt form that has better skin permeability and fewer adverse effects. In the present study, diclofenac epolamine (180 mg) in adhesive type topical patch, were prepared using three different grades of sodium carboxymethyl cellulose viz., LF, M1F and MF. Mixtures of transdermal enhancers like propylene glycol and butylene glycol, humectants and other excipient were included as part of the vehicle. Cumulative permeation and flux studies were carried out through Strat-M® membrane using Hanson and Franz diffusion cell, respectively. Adhesion study was carried out to see its effectiveness towards longer adhesion time onto the skin. The results were compared with marketed product, Flector®. It was found that the M1F grade was best for the topical patch formulation and as much effective as the marketed product in terms of its drug delivery and skin adhesion properties.