Preparation of Nano‐Emulsion‐Based Hydrogels Conjugated Curcumin as Model Functional Lipid Bioactive Compound

Abstract The preparation of nanoemulsion‐based alginate hydrogels, containing curcumin was the aim of current study. The nanoemulsions of coconut oil were prepared using solvent‐displacement technique and then the obtained nanoemulsions were converted to hydrogels using the ion‐gelling process. The effects of formulation parameters, namely, sodium alginate concentration (1–2 g L−1), the weight ratio of calcium chloride to sodium alginate (2–4), and curcumin to sodium alginate (1–3), were also evaluated on swelling percentage, gel fraction, curcumin load, curcumin release, and antibacterial inhibitory zone of hydrogels. All studied characteristics were successfully correlated to the selected independent variables by second‐order polynomial equations as models, with relatively high coefficients of determinations (R2 > 86). According to multiple numerical optimization analysis, the most desired hydrogels can be obtained using 1.9 g L−1 sodium alginate, curcumin/sodium alginate of 2.5 g g−1, and calcium chloride/sodium alginate of 2.2 g g−1, with the maximum swelling ratio (216%), gel fraction (29.9%), curcumin load (59.12%), antibacterial activity (clear‐zone diameter of 5.27 cm), and the least curcumin release after 12 hours (87.75%). It was also resulted that the curcumin release from prepared optimum hydrogel obeys the first order kinetics. No significant differences between the measured and predicted data confirmed the suitability of suggested models.