Preparation And Evaluation Of Anti-aging Lipid Nanocapsules

Astaxanthin and sphingolipid are effective antioxidant and anti-aging ingredients.However,the application of them is often limited owing to their high melting point,poor water soluble,bad stability and low bioavailability.So,the technology of nano carrier was used in this paper to solve these problems of the two kinds of active ingredients.Besides,the natural source of lecithin was selected as the emulsifier,which not only plays the role of protective agent,but also acts as a nutritional enhancer.The astaxanthin lipid nanocapsules(ASX-LNC)were prepared by high pressure homogenization.The formulation and process were optimized by the single factor experiment.The average particle size,encapsulation efficiency,morphology and infrared spectrum of ASX-LNC were investigated.The results showed that the average particle size and PDI of optimized ASX-LNC was 98.1 ± 1.5 nm and 0.09 ± 0.01 respectively.The encapsulation efficiency of astaxanthin was more than 90%.The result of transmission electron microscopy showed that the shape of ASX-LNC was regular and spherical,and the distribution was uniform.The infrared spectra proved that the astaxanthin was encapsulated in lipid nanocapsules better.On this basis,the stability and in vitro evaluation of ASX-LNC were carried out.The physical stability was investigated by change of particle size and PDI under different conditions.The results showed that ASX-LNC has good physical stability.The chemical stability of ASX-LNC was investigated under light and high temperature.The results showed that the stability of astaxanthin was improved after being encapsulated in lipid nanocapsules.Percutaneous behavior studies showed that ASX-LNC could change the tight structure of the corneum and promote the osmotic absorption of astaxanthin,and increase the retention of astaxanthin in skin.Antioxidant experiments showed that the antioxidant activity of astaxanthin was not affected after being encapsulated.The cytotoxicity and skin irritation test showed that ASX-LNC was safe and had no irritation to the skin.The sphingosine lipid nanocapsules(SPG-LNC)were also prepared by high-pressure homogenization.Their micromorphology,infrared spectrum,stability,closure effect,cytotoxicity and skin irritation were studied.The particle size and PDI of SPG-LNC was 161.5 ± 3.4 nm and 0.27 ± 0.02 respectively,and had good physical stability.The results of infrared spectra showed that the sphingosine was encapsulated in this system.The test of closure effect suggested that SPG-LNC had good moisturizing activity.In addition,the cytotoxicity showed that the SPG-LNC has good safety in a certain range.Finally,the ASX-LNC was added in skin care products.The results showed that after being added in the products,the light and thermal stability was slightly decreased,and the the active ingredients could still be released.The antioxidant test showed that compared to the products without ASX-LNC,the products added ASX-LNC showed obvious antioxidant activity.These results also proved that the anti-aging lipid nanocapsules could be applied in the field of cosmetics well.