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

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, 400ml oil, 0.05M CaCl₂ and 100ml surfactant was recognized as the optimized treatment with a reasonable encapsulation efficiency of 5.6% and a nanoparticle size of 785nm.