Colloidal Characteristics,Drug Encapsulation,and Oil-in-Water Emulsion of Dodecenyl-Modified Alginate

Sodium alginate was hydrophobically modified with dodecenyl succinic anhydride in a neutral aqueous solution (pH = 6.8) at room temperature, forming an environmentally friendly amphiphile dodecenyl-modified alginate (DMA). Surface activity of DMA was assessed using surface tension and zeta-potential measurements. Hydrophobic compound-loading capacity as well as oil-in-water emulsion stability of DMA solutions were investigated to study the potential applications of DMA. The critical micelle concentration (CMC) of DMA aqueous solution was found to be 0.70 mg mL⁻¹ with the surface tension being around 33.0 mN m⁻¹. DMA solutions were able to solubilize hydrophobic compounds like Sudan IV and Clofazimine in aqueous medium. 10% peanut oil-in-water emulsions stabilized by 10 mg mL⁻¹ DMA presented good stability during 7 days of storage and the interfacial tension between water and oil was lowered from 23.0 to 9.0 mN m⁻¹. Results showed that DMA was an efficient surfactant and could work as a drug-delivery vehicle or a natural food emulsion stabilizer in the future.