Encapsulation of mangosteen extract in virgin coconut oil based nanoemulsions: Preparation and characterization for topical formulation

Nanoemulsions containing extract of mangosteen (Garcinia mangostana L.) rind has been developed and characterized as a topical formulation. The encapsulation of mangosteen extract in nanoemulsions is considered a promising strategy to utilize the available bioactive compounds, particularly α-mangostin. In this study, a high-speed homogenization method was used to produce nanoemulsions of virgin coconut oil as the oil phase, combined Tween 80 and Span 80 as the oil-in-water surfactant, and distilled water as the aqueous phase. The homogenizer speed, oil and surfactant composition, and, hydrophilic lipophilic balance values of the surfactants were varied in order to get the stable nanoemulsions formulation. The most stable nanoemulsion was obtained using a homogenizer speed of 8000 rpm, oil to surfactant volume ratio of 1:1.4, and surfactant hydrophilic lipophilic balance value of 12. Nanoemulsion formulation with average droplet size of 181 nm, zeta potential of-30.9 mV, and 0.01% α-mangostin loading was stable for 28 days without phase separation. Based on the accelerated stability test, the nanoemulsion shelf life is estimated to reach one year. The present study revealed that the virgin coconut oil-based nanoemulsion is a promising carrier of mangosteen extract for topical formulation.