Effect of emulsifier type and dispersed phase on the synthesis of curcumin nanoemulsions and in vitro release

Abstract

Curcumin is a polyphenol recognized for its beneficial effects; however, it has low solubility, which limits its bioavailability and effectiveness. Its application in nanoscale delivery systems allows these limitations to be overcome. The objective of this study was to evaluate the effect of composition variables on the formation of curcumin nanoemulsions and their in vitro release. The methodology used consisted of evaluating the effect of pre-emulsification conditions, type of emulsifier (Tween 40, Tween 80, and phosphatidylcholine), dispersed phase (coconut oil and omega 5), and pH on globule size and nanoemulsion stability. The trapping efficiency and in vitro release of curcumin were determined. Among the results, it was found that curcumin nanoemulsions with medium-chain oil and pomegranate seed oil stabilized with Tween 40 showed the smallest particle size (23 and 33.4 nm, respectively) and were stable for 7 weeks. When phosphatidylcholine was evaluated as an emulsifier, the globule sizes were 90.7 and 126.2 nm, respectively. The curcumin entrapment efficiency was 93%. Factors such as pH show a change in globule size; however, the type of emulsifier used influences stability. It is concluded that the release of curcumin shows different behavior at the nanometric scale compared to the coarse form. Composition variables significantly affect the characteristics of nanoemulsions, their stability during storage, and influence the release of curcumin and, therefore, its bioavailability.