Development and Optimisation of Olive Oil-infused Emulgel from <i>Andrographis</i> Extract Using Quality by Design (QbD) Methodology

Abstract

Background: Andrographolide, the primary active constituent in Andrographis extract, exhibits poor aqueous solubility, necessitating a novel formulation strategy for effective dermal delivery. Aim: To formulate and optimise olive oil-infused emulgel from Andrographis extract. Methods: Various emulgel formulations were prepared using different combinations of oil and Carbopol 940. The formulations were assessed for visual inspection, pH, spreading ability, extrudability, viscosity, drug content, and in vitro drug release. The optimal formulation (AEE 6) was identified using design expert software based on the evaluated parameters. Results: The emulgel formulations demonstrated varied properties based on the combinations of oil and Carbopol 940 used. The optimized formulation (AEE 6) showed favourable stability under accelerated conditions, maintaining stability across all assessed physicochemical parameters. Conclusion: The emulgel formulation approach successfully addressed the poor aqueous solubility of andrographolide, enhancing its permeation for dermal delivery. The selected formulation (AEE 6) demonstrated optimal characteristics and stability, making it a promising candidate for effective dermal delivery of Andrographis extract.