Discussion On The Rule Of Oils In Structure Which Could Form Free Alcohol Microemulsion And Exploitation Olive Oil Alcohol-free Microemulsion In Cosmetic

Objective:Generally,microemulsion formation requires a high concentration of surfactant?S?and cosurfactant?CoS?to reduce interfacial tension and improve the stability of interfacial film.However,the cytotoxicity and skin irritation caused by the extensive use of S and CoS limit the development and application of microemulsion in medicine and cosmetic.Our previous research found that CoS was not a necessary condition for the microemulsion formation.The purpose of this paper was to explore the rule of oils in structure which could form free alcohol microemulsion,so as to prepare a alcohol-free microemulsion carrier with low concentration surfactant,and apply it in the development and application of cosmetic.Methods:Several different structures of oil were selected to prepare the pseudo-ternary phase diagrams by water titration in the presence or absence of CoS.According to the size of the microemulsion area,we investigated the influence of CoS and its species on the microemulsion formation of different structural oils,and looked for the rule of oils in structure which could form free alcohol microemulsion.Based on the physical and chemical properties of the formed microemulsion,such as particle size,PDI,turbidity,viscosity and surface tension,the mechanism of microemulsion formation without CoS was discussed.The facial mask using alcohol-free microemulsion of olive oil as carrier was prepared by adding vitamin E succinate,hyaluronic acid,collagen,sodium alginate,arbutin,and allantoin.The screening of facial mask formulation was based on ternary phase diagram and appearance.The microemulsion characteristics of the facial mask were characterized by the appearance,pH,particle size,viscosity and transmission electron microscopic observation.The moisturizing effect of the facial mask was evaluated using a commercially available mask as the reference substance.To establish a HPLC analysis method of the arbutin,the same amount of arbutin as that of the microemulsion mask was added into the reference substance of the marketed mask.Taking transdermal absorption capacity of arbutin as evaluation index to investigate the transdermal absorption effect of the self-made microemulsion mask for the active substance.We selected olive oil,?-linolenic acid and linoleic acid microemulsion as the carrier without CoS,which was added menthol,hyaluronic acid,collagen,glycerin and angelica as the active ingredients.Then it prepared a microemulsion gel-like lipstick.According to the ternary phase diagram,the formulation of microemulsion was screened,and the water content was determined by the appearance characteristic.Then it could be directly formed to lipstick matrix.The type of microemulsion was judged by conductivity.Particle size,pH,viscosity were used to characterize the physicochemical properties of microemulsion lipstick,and the stability of lipstick was evaluated by changes in appearance and physicochemical properties.The safety,moisturizing and oil absorption effects of the microemulsion gel lipstick were evaluated by using the commercially available gel lipstick as the reference substance.Results:The study found that the influence of CoS on the microemulsion region with different types of oil depended on the oil structure.If the structure of the oil have no hydroxyl groups,such as isopropyl myristate,isopropyl palmitate or ethyl oleate,the formation of microemulsion required CoS to assist S to improve oil/water interface stability and promote microemulsion formation.If the structure of the oil contains hydroxyl functional groups,such as olive oil,linoleic acid,?-linolenic acid,and caprylic capric triglycerride,the formation of microemulsion doesn't require the participation of CoS.The addition of CoS even inhibits the formation of microemulsion,and different CoS had different level of effects on the microemulsion region.The best formulation of the olive oil microemulsion mask was composed of olive oil2.383%,vitamin E sucrose 0.397%,S 4.17%,mixed hyaluronic acid 0.3%,sodium alginate 0.1%,allantoin 0.1%,collagen 0.5%,arbutin 1%,glycerol 5%,and so on.The viscosity was 25.94±0.11 Pa·s;the average particle size was 58.83±0.79 nm;the transmission electron micrographs showed the droplet was round.All of these were in line with the characteristics of microemulsion.The pH of the facial mask was 5.6±0.1,which was suitable for human skin pH environment.The mixture of hyaluronic acid,collagen and sodium alginate played a moisturizing role in the facial mask,and compared with commercial facial mask,the moisturizing effect of the self-made microemulsion gel facial mask increased by 5.5%.HPLC analysis conditions of arbutin in the facial mask:the chromatographic column was Kromasil 100A C₁₈8 column?4.6 mm×250 mm,5?m?,and the detection wavelength was 278 nm.The mixture of methanol and water solution?10:90,v/v?was used as the mobile phase with a flow rate of 0.8 ml/min.The column temperature and the injection volume were 30^?C and 10?L,respectively.The Linear range of arbutin concentration was 0.05¹0 mg/mL;the RSD of repeatability,stability,intra-day and inter-day precision was<1%;the average recovery rate was 96.8%,and the RSD was1.94%?<2%?.This all meet the methodological requirements.Using saline as the receiving solution,the steady-state infiltration rates of 1%arbutin from the facial mask through the isolated cavy skin was 0.305 mg·cm^-2·h^-1,which was 4.29 times higher than that from the marketed mask.This product was safe and stable,that meets the sensory and physicochemical indexes of the national light industry standard.The best formulation of the lipstick was composed of oil ester 14.71%,vitamin E succinate 2.45%,S 25.73%,menthol 0.2%,angelica extract 1%,glycerol 5%,collagen0.5%,transparent acidic acid 0.3%and so on.The appearance of microemulsion lipstick was pink,clear and transparent gel;pH was 5.70±0.036;the particle size was 28.31±0.45nm and the average viscosity value was 27.4±0.632 Pa·s,which had good spreadability under the viscosity.The physical stability and heat-cold resistant test proved that the self-made lipstick had good stability.Its moisturizing effect and oil absorption effect were better than the commercially available lipstick.The t-test analysis showed there was a significant difference between the self-made lipstick and the marketed lipstick?P<0.01?.Conclusion:In this study,we found the rule of oils in structure which could form free alcohol microemulsion.The alcohol-free microemulsion was applied to the exploitation cosmetic,which showed a good effect of promoting skin penetration.This discovery can solve the safety problem caused by the extensive use of alcohol in microemulsion,and provides a greater possibility for the promotion and application of microemulsion as an excellent carrier in the development of drug and cosmetic.