Development of a Carprofen-Loaded Nanoemulsion for Topical Management of Post-Surgical Inflammation

Background/Objectives: Carprofen (CP) is a potent non-steroidal anti-inflammatory drug whose clinical use is limited by systemic adverse effects associated with oral administration. The aim of this study was to develop and evaluate a CP-loaded nanoemulsion (CP-NE) as a topical formulation for the management of post-surgical inflammation in veterinary applications. Methods: CP-NE was physicochemically characterized in terms of droplet size, polydispersity index, morphology, pH, rheological behavior, spreadability, and stability. Biopharmaceutical performance was assessed through in vitro drug release and ex vivo permeation studies using porcine ear skin. Safety was evaluated using in vitro cytotoxicity assays in HaCaT keratinocytes, histological analysis of ex vivo porcine skin, and assessment of biomechanical skin parameters in mice. Finally, anti-inflammatory efficacy was investigated in a murine model. Results: CP-NE showed a mean droplet size of approximately 140 nm, low polydispersity, spherical morphology, and Newtonian flow behavior with good spreadability. Stability studies confirmed the absence of significant physical destabilization and acceptable chemical stability under refrigerated and room temperature conditions. Release studies demonstrated sustained drug release, while permeation assays revealed low systemic exposure and high drug retention within the skin. Safety evaluations indicated good biocompatibility with no cytotoxicity, no histological alterations in skin tissue, and no alteration of the skin's biomechanical properties in volunteers. In vivo efficacy studies showed that CP-NE significantly reduced post-surgical inflammation, promoting faster restoration of skin architecture and improved wound appearance. Conclusions: These findings suggest that CP-NE represents a promising topical delivery system for localized anti-inflammatory therapy following surgical procedures, offering significant potential for veterinary applications.