Development of a nutraceutical nano-delivery system through emulsification/internal gelation of alginate

•Alginate nano-carriers prepared by a low energy internal gelation technique.•Size of nanoparticles decreased at higher oil and surfactant contents.•Encapsulation efficiency was inversely proportional to the size of nanoparticles.•0.5% alginate, 400 ml oil, 0.05 M CaCl2 and 100 ml surfactant was the optimized point.

Alginate nano/microspheres are produced by emulsification/internal gelation of sodium alginate dispersed within vegetable oils containing surfactant, followed by CaCl2 addition resulting in hardened particles. In this work, the impact was evaluated of alginate, CaCl2, oil and surfactant content on the size and encapsulation efficiency of nanocarriers containing peppermint phenolic extract and prepared by a low energy internal gelation technique. The results revealed that size of nanoparticles decreased at higher oil and surfactant contents, higher molarity of CaCl2 and lower alginate concentrations. Also, it was found that the encapsulation efficiency was inversely proportional to the size of nanoparticles, and the impact of alginate concentration and surfactant content was markedly higher than the other two factors. The composition of 0.5% alginate, 400 ml oil, 0.05 M CaCl2 and 100 ml surfactant was recognized as the optimized treatment with a reasonable encapsulation efficiency of 5.6% and a nanoparticle size of 785 nm.

Graphical abstractSchematic presentation of the internal gelation procedure; (a) shrinkage of alginate sodium droplets; (b) crosslinking with calcium ions.Download high-res image (74KB)Download full-size image