Control release of holy basil essential oil nanoemulsion dispersed in hydrogel for biomedical applications

Abstract

Holy basil essential oil (HBEO) is a therapeutic agent recognized for its antioxidant, anti-inflammatory, and wound-healing properties. However, its clinical use is limited by poor aqueous solubility, volatility, and instability. Nanoemulsion (NE) is an effective strategy to overcome these limitations. In this study, 1% HBEO in 0.5% polyvinyl alcohol (PVA) aqueous solution formulation yielded nanosized droplets (182 ± 3 nm, PDI = 0.286) and showed sustained release, with 92% drug release over 30 h, compared to the rapid release for 1% HBEO in pure water. To further enhance stability and biocompatibility, the HBEO nanoemulsion (HBEO-NE) was incorporated into a glutaraldehyde (GA) crosslinked gelatin/carboxymethyl cellulose CMC (3:1) hydrogel matrix. The resulting hydrogel exhibited a swelling ratio of 8 (g/g) and an HBEO loading capacity of 67.5%. The cytotoxicity of HBEO/gelatin/CMC hydrogel was observed with less cytotoxicity compared to the natural release of HBEO-NE without a hydrogel matrix. These results demonstrate the HBEO-NE-loaded gelatin/CMC hydrogel as a robust platform for controlled release in drug delivery systems.