Formulation and Evaluation of Diclofinac Sodium Topical Spray

Diclofenac sodium is a widely used non-steroidal anti-inflammatory drug (NSAID) for the management of pain and inflammation; however, its oral administration is associated with systemic side effects such as gastrointestinal irritation and renal complications. Topical drug delivery systems have emerged as a promising alternative by providing localized action with reduced systemic exposure. Among these, topical sprays, particularly microemulsion-based systems, offer advantages such as enhanced drug solubility, improved skin permeation, and better patient compliance. The selection of an appropriate formulation vehicle plays a crucial role in influencing drug release, stability, and skin permeation. In the present study, the formulated diclofenac sodium topical spray demonstrated satisfactory physicochemical properties including suitable pH, viscosity, and homogeneity, along with high drug content and excellent stability. In vitro drug release studies showed more than 90% drug release, while permeation studies confirmed enhanced skin penetration compared to conventional formulations. The microemulsion-based spray system exhibited superior performance due to its small droplet size and improved solubilization capacity, and topical application resulted in higher drug concentration at the target site with significantly lower systemic absorption, indicating improved safety and therapeutic efficacy.