Studies On Preparation And Properties Of Ascorbic Acid Nanoliposomes

Vitamin C is water soluble,it has the effect of skin lightening and anti-aging,but it is easy to oxidative deterioration, and not easily penetrate through the skin. As a new drug carrier,liposomes has the effect of protecting the core material encapsulated and improving the bioavailability of drugs.As the core material, Vitamin C was prepared to Vitamin C liposomes and Vitam in C nanoliposomes using dynamic high-pressure microfluidization (DHPM) as a core technology which combined with the traditional method of liposomal preparation. In addition, both the physical and chemical properties of liposomes (mean particle size, encapsulation efficiency, morphology, stability, time-controlled releasing,) and bioavailability (antioxidant capacity and skin permeability.) were characterized.The analysis method of determinating entrapment efficiency of vitamin C liposomes was established:separated free vitamin C by dialysis, breaken the liposomes by methanol emulsion, determinated Vitamin C content by UV spectrophotometry.The traditional liposomal preparation methods and DHPM combined with the traditional method of liposomal preparation were developed to prepare vitamin C liposomes and vitamin C nanoliposomes, respectively. Each factor was analyzed and the orthogonal test was taken to optimize the formula.The optimized formula of vitamin C liposomes as follows:the preparation temperature was 65℃,the concentration of vitamin C was 2 mg/ml, the mass ratio of vitamin C and lipids was 1:25, the mass ratio of phospholipid and cholesterol was 5:1, the mass ratio of Tween-80 and lipids was 2:10,the mass volume ratio of phospholipid and ethanol was 2.5:100. The optimized formula of vitamin C nanoliposomes as follows:the preparation temperature was 60℃,the concentration of vitamin C was 5 mg/ml, the mass ratio of vitamin C and lipids was 1:10, the mass ratio of phospholipid and cholesterol was 4:1, the mass ratio of Tween-80 and lipids was 4:10,the mass volume ratio of phospholipid and ethanol was 10:100,the treatment pressure and times were 120 MPa and 4.The physicochemical properties of both vitamin C liposomes and vitamin C nanoliposomes were evaluated.Vitamin C nanoliposomes had advantages over vitamin C liposomes with the encapsulation efficiency(47.16±6.28%),the mean particle size(73.9±4.4 nm),showed a solid spherical morphology,good storage and vivo stability,significantly slow release.Compared the antioxidant capacity and the skin penetration of vitamin C liposomes and vitamin C nanoliposomes, results showed that, compared to free vitamin C,the antioxidant capacity of two types of liposomes was not affected; he order of skin penetration was:Vitamin C nanoliposomes> Vitamin C liposomes> Free Vitamin C.