FORMULATION AND EVALUATION OF A NANOEMULGEL CONTAINING INDOMETHACIN AND BROMELAIN FOR LOCALIZED ANTI-INFLAMMATORY ACTIVITY

Abstract

Objective: This study aimed to develop and evaluate a topical nanoemulgel containing indomethacin and bromelain for effective localized anti-inflammatory therapy.

Methods: Nanoemulsions were formulated using eucalyptus and nirgundi oils as the oil phase, Tween 20, and propylene glycol as the surfactant and co-surfactant. Pseudo-ternary phase diagrams identified the largest nanoemulsion region at Smix 1:1. The nanoemulsions were incorporated into Carbopol 934 to obtain nanoemulgel. Preformulation studies and FTIR and DSC analyses confirmed drug-excipient compatibility, while molecular docking showed strong binding of indomethacin and bromelain to inflammatory targets, including COX-2 and TNF-α. The physicochemical parameters of nanoemulgel, including globule size, PDI, zeta potential, pH, viscosity, spreadability, and extrudability, were evaluated. In vitro anti-inflammatory activity was assessed using protein denaturation and HRBC membrane stabilization assays, while permeation was studied using Franz diffusion cells.

Results: The formulations (F1-F5) demonstrated nanoscale droplets ranging from 119.6 to 189.4 nm, with zeta potential between −12.0 and −19.2 mV. The pH values were between 6.50 and 6.73, and the viscosity was approximately 21.355–21.392 mPa·s. The spreadability was measured between 33.01 and 39.32 g·cm/s, and extrudability ranged from 61.00% to 74.81%. The in vitro anti-inflammatory activity of formulations F3 and F4 was significant and comparable to that of a marketed indomethacin gel. Franz diffusion studies indicated an increase in cumulative permeation over time, with high flux and permeation coefficients.

Conclusion: The developed nanoemulgels, particularly F3, exhibited satisfactory rheological properties, enhanced drug permeation, and significant anti-inflammatory activity comparable to that of a marketed indomethacin gel formulation.