Formulation and Evaluation of Etoricoxib Emulgel for Effective Topical Drug Delivery

ABSTRACTBackground: Etoricoxib, a selective COX-2 inhibitor, is widely used in the management of pain and inflammatoryconditions. Oral administration is associated with gastrointestinal (GI) side effects limiting long-term therapy.Topical delivery via emulgel offers an effective alternative by bypassing first-pass metabolism and providinglocalized drug action. Objective: To formulate, optimize, and evaluate an Etoricoxib emulgel using varyingconcentrations of Carbopol 934, HPMC K15M, liquid paraffin, Tween 80, and propylene glycol. Methods: Ninebatches (F1–F9) were prepared using a microemulsion-gel technique. Formulations were evaluated for physicalappearance, pH, viscosity, spreadability, extrudability, drug content, in-vitro drug release, release kinetics, andstability. Results: All formulations showed acceptable physicochemical properties. The optimized batch F2(Carbopol 934 at 1.5%) exhibited the highest drug content (97.69 ± 1.25%), best spreadability (21.96 ± 0.34g·cm/s), viscosity of 26,687 cps, and maximum cumulative drug release of 96.8% at 6 hours. Drug release followedzero-order kinetics (R2 = 0.9906). Accelerated stability studies at 40°C/75% RH for 45 days confirmed nosignificant changes in physicochemical parameters. Conclusion: Etoricoxib emulgel (Batch F2) is a promising,stable, and patient-friendly topical drug delivery system offering enhanced drug release and improved tolerabilityover conventional oral NSAID therapy.