Encapsulation of Polyphenolic Antioxidants from Cratoxylum formosum ssp. formosum Leaf Extract in Nanostructured Lipid Carriers for Cosmetics applications

Abstract

Introduction: Cratoxylumformosum ssp. formosum (CFF) leaf extract contains high amount of polyphenolic content and has strongly antioxidant activity but its high aqueous solubility may lead to low skin permeation. Encapsulation of the CFF extract in nanostructure liquid carriers (CFF-NLC) is an interesting method to enhance the delivery of the active into deeper layer of skin. Objective is encapsulation the CFF extract in nanostructured liquid carriers (NLC) and  2⁴-factorial central composite design was used to obtain the obtimized formulations. Materials and Method: Phenolic compounds from CFF leaves were extracted in the mixture of ethanol 78% and water. The amount of phenolic compound in the CFF was determined by using  5-O-caffeoylquinic acid as a standard biomarker. Antioxidant activity was assessed by DPPH^·free radical scavenging assay. The CFF-NLC was then prepared using hot melted homogenization using a 2⁴-factorial central composite design. The CFF-NLC was composed of Compritol^®888 ATO+GMS^®1:1), Lexol^® GT 865, Tween^®80+Lutrol^® F68 (1:1) and CFF. Results: The CFF extract showed IC₅₀ value of 26.49±1.27 µg/mL with amount of 5-O-caffeoylquinic acid at41.66±0.07 mg/g. The optimum conditions for CFF-NLC preparations wereX₁ = 5.77%w/w, X₂= 45%w/w, X₃= 3.3%w/w, and X₄= 2%w/w. The mean particle size of the optimum CFF-NLC, polydispersity index, zeta potential, and entrapment efficiency were 125.67±3.21 nm, 0.158±0.011, -11.20±0.40 mV and 57.58±3.14%, respectively. The experimental values were well correspondent to the predicted values obtained from the proposed mathematical model. Encapsulation of CFF extract into NLC gave a controlled released property and improved skin permeation. Conclusion: CFF-NLC was a promising candidate for delivery the antioxidants for further cosmetic applications.