Optimization of Small Droplet Lantana oil-based Nanoemulsion for Enhanced Curcumin Release

Nanoemulsions are well-established carriers for improving the solubility, stability, and availability of hydrophobic bioactive compounds. Curcumin is a well-known phytochemical with a wide range of medicinal benefits that are constrained due to limited solubility and bioavailability. The main goal of this study is to formulate a stable small droplet oil-in-water (O/W) nanoemulsion system of curcumin in Lantana oil to improve the bioavailability of the former. Curcumin-loaded lantana oil with the addition of NaCl (NaCLO1- NaCLO4) increased the stability and reduced droplet size resulting in emulsions that were stable for up to three months. Nanoemulsions produced via sonication of NaCLO1-NaCLO4 for 5 min had sizes ranging 26.55 ± 2.4 to 114.1 ± 12.9 nm with a PDI of 0.3. Extending sonication to 15 min lead to a more uniform size distribution, with droplet sizes between 40.21 ± 2.1 to 55.75 ± 1.3 nm and PDI values between 0.15 and 0.33. Further, nanoemulsions were also analysed by thermodynamic stability experiments. The kinetics of curcumin release was examined in the final emulsion and fitted in different models to find the best fit. Three pH conditions were tested for this using sodium citrate (pH 3), phosphate (pH 7.4), and carbonate-bicarbonate buffers (pH 10.6). The Korsmeyer-Peppas model showed the best fit, suggesting a diffusion-controlled mechanism. The study discovered that the ideal ratios of oil and surfactant improved the release of curcumin, but changes in the percentage of water had a major impact on it. Graphical Abstract Diagram notes 1. Curcumin and lantana oil heated at 50°C. 2. Tween 80 and water added to the mixture. 3. Magnetic stirring at 1200 rpm for homogeneous blend. 4. Sonication to reduce droplet size. 5. Nanoemulsion characterized using DLS, Zeta Potential, pH analysis, and TEM. 6. Nanoemulsion shows efficient curcumin release across different pH levels. 7. Promising system for curcumin delivery in biomedical applications.