Study Of The Application Of Proanthocyanidin And Its Liposome In Cosmetics

The cosmetics produced by plant extracts, have been paid much attention by cosmeticsdevelopers for its idea of green, nature and health. Proanthocyanidins are extracts of grapes,blueberries, pine needles and other plants, which are not only natural, effective, non-toxic, but alsofunctional as the performances of anti-wrinkling, whitening, sunscreen, moisturizer, anti-radiationand beautifying. However, proanthocyanidin has many disadvantages of poor stability, such assusceptible to oxidation, light, heat and pH. Accordingly, its application is greatly limited due tothe above-mentioned disadvantages. Therefore, developing proanthocyanidin liposome cosmeticswith qualities of strong effect, good stability and non-toxic, will have broad prospects and value.Unfortunately, there will be a lot of problems in the industrialization of proanthocyanidinliposome. First of all, how to determine the content of proanthocyanidin and add the accurateamount of proanthocyanidin liposome to the cosmetics? Secondly, what’s the encapsulationefficiency of the liposome? Additionally, the question of how about the antioxidant propertiescompared to the other antioxidants such as vitamin E deserves to be researched, either. Finally,organic solvents used to prepare the liposome have the residual problem, which not only has theirritant odor, but also is toxic and harmful to the skin. Hence, it is necessary to solve the problemsin industrialization for preparing proanthocyanidin liposome.The content of this study is showed as follows:1. Determined of the content of proanthocyanidin and the encapsulation efficiency of theproanthocyanidin liposome. Three methods were investigated to determine the content ofproanthocyanidin, namely ultraviolet (UV) spectrophotometry, high performance liquidchromatography (HPLC) and iron catalytic colorimetry. Proanthocyanidins were measured by UVspectrophotometry, and the absorption wavelength was201nm, the linear region was0.5-6.0μg/mL, the regression equation was y=0.2147x+0.0049, regression coefficient was0.9999.The average encapsulation efficiency of the proanthocyanidin liposome was95.25%, the relative standard deviation (RSD) was1.34%. Satisfactorily, the results show that this method (UV) wassimple, accurate and reliable.2. The detecting method for antioxidant activity of proanthocyanidin and vitamin E wasstudied, and three models of antioxidant activities such as DPPH free radical method, ABTS·+freeradical method and pyrogallol self-oxidation method were developed. Results showed that therewas a good linear relationship between the respective concentrations and the DPPH free radicalscavenging rate within a certain range of concentrations of proanthocyanidin and vitamin E. Theregression equations of proanthocyanidin and Vitamin E against DPPH· werey=8.0554+1127.0x(R2=0.9995) and y=4.3647+403.72x(R2=0.9995), respectively, under the samereaction time of80min. Additionally, the linear regression equations of proanthocyanidin andVitamin E against ABTS·+were y=2913.1x+1.6301(R2=0.9992) andy=2799.3x+1.0883(R2=0.9991), and the reaction time was30min and15min, respectively.Furthermore, the free radical scavenging rate increased with time, but did not change to a certainextent. Finally, the SOD value of proanthocyanidin was negative, which proved that pyrogallolself-oxidation was not suitable for the evaluation of antioxidant capability of proanthocyanidin.3. While the proanthocyanidin was as the active ingredient, ethyl ether was choosen as thesuitable organic solvent to prepare proanthocyanidin liposome. Then the residual organic solventin proanthocyanidin liposome was removed by nitrogen-blowing for20min. The detection ofresidual solvent content was developed by head-space gas chromatography. Adopting the ethanolas an internal standard, under the optimal chromatographic conditions, the calibration curve ofethyl ether showed good linearity (R2=0.9993) in the range of3.124～23.430μg/mL, and therecovery was95%~120%with the relative standard deviation (RSD) less than4.72%, the limit ofdetection was1.616μg/mL (S/N=3). To our satisfactory, the ethyl ether residue inproanthocyanidin liposome through the treatment of nitrogen-blowing was0.037%, much lowerthan the ethyl ether residue limit of0.5%permitted by Pharmacopoeia of the People’s Republic ofChina (PRC codex) under optimal measurement conditions.