Pharmacokinetic Assessment of Aceclofenac In-Situ Gel Vs. Conventional Topical Formulations: A Bioavailability Enhancement Study

Abstract

Aceclofenac is a widely prescribed non-steroidal anti-inflammatory drug (NSAID) for the management of rheumatoid arthritis and musculoskeletal inflammation. However, conventional topical Aceclofenac and Diclofenac gels exhibit limited permeation, rapid clearance from the skin surface, and poor localized bioavailability. Thermoresponsive in-situ gel systems have emerged as potential delivery platforms due to their ability to undergo sol–gel transition at physiological temperature, enhancing skin retention and promoting sustained drug diffusion. This study evaluates the pharmacokinetic performance of a novel Aceclofenac in-situ gel compared with a marketed conventional topical formulation. Wistar rats were administered equal doses of Aceclofenac, and plasma samples were analyzed using a validated HPLC method. Pharmacokinetic parameters including Cmax, Tmax, AUC0–t, AUC0–∞, t½, and MRT were calculated using non-compartmental analysis. Results demonstrated that Aceclofenac in-situ gel achieved significantly higher Cmax and AUC values, prolonged Tmax, and extended half-life compared to the commercial gel, indicating improved absorption and sustained release. The enhanced bioavailability is attributed to increased retention time, improved permeation, and controlled release behavior of the in-situ gel. These findings support the potential of thermoresponsive gels as superior topical delivery systems for anti-inflammatory therapy.