Formulation of a Cosurfactant‐Free O/W Microemulsion Using Nonionic Surfactant Mixtures

Abstract

A cosurfactant-free O/W microemulsion composed of oil, a mixture of hydrophilic and hydrophobic surfactants, and water has been developed using food-grade components as a nutrient delivery system. We started our investigation to monitor the phase behavior of this system based on a hydrophilic surfactant (Tween 80). From a phase diagram, the weight ratio of 5.4:33.8:60.8 = oil:surfactant:water was selected as a combination ratio for the O/W microemulsion system. We also investigated the combination effect of different hydrophobic surfactants to Tween 80 on microemulsion formation. Use of hydrophobic surfactants with Tween 80 produced smaller droplets than Tween 80 alone. Rheological studies showed that all microemulsions followed shear-thinning behavior. The turbidity of microemulsions did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. When docosahexaenoic acid (DHA) oil was applied to this microemulsion system, the particle size and the turbidity were not significantly changed. Dilution with a different aqueous medium, either water or acidic fluid, did not significantly change the microemulsion turbidity. DHA oil incorporated in microemulsion showed higher oxidation stability than free DHA oil.

Characterization of Microemulsions Prepared using Isopropyl Palmitate with various Surfactants and Cosurfactants

“…Meanwhile, Tween 80 produced a higher volume of microemulsion than Tween 60, although both have the same number of carbon chain. These results are in a good agreement with those obtained by Cho et al and Sintov et al [16,17]. The addition of cosurfactant is crucial to obtain a microemulsion system.…”

Enhanced Antioxidant Activity of Capsicum annuum L. and Moringa oleifera L. Extracts after Encapsulation in Microemulsions

“…However, there were no significant differences between the samples. Results are in line with those of Cho [32] who also concluded that the turbidity of MEs did not change after accelerated stability tests, indicating that this microemulsion system was stable under the given harsh conditions. Turbidity determination results correlated well with those taken from the thermal and centrifugation stability tests, which also indicated the thermodynamic stability of the samples.…”

Curcumin-loaded colloidal carrier system: formulation optimization, mechanistic insight, ex vivo and in vivo evaluation

“…Heating results in randomness due to increase in enthalpy, while cooling results in loss of entropy or coalescence, leading to an increase in particle size. 37 …”