Preparation Of Rana Sylvestris Polypeptide Skin Topical Nano-emulsion And Freeze-dried Powder

Peptides have good application prospects in cosmetic fields,such as the high biological activity,non-toxicity and homologous assimilation.As the by-products of Rana Chensinensis,the bioavailability of the Rana Chensinensis was greatly improved by the extraction of the peptides from Rana Chensinensis skin.In this study,the extraction of antibacterial peptide from Rana sinensis skin was carried out by the combination of acid hydrolysis and enzymatic hydrolysis.By optimizing the extraction conditions of R.sinensis peptides,the optimal extraction conditions for the experiment were optimized as follows: the extraction solvent was a mixture of 4% HAc and 0.1% neutral protease,the p H was 4.5,the extraction time was 6 h,the extraction temperature was 37 °C,the liquid-to-liquid ratio was 5:1.The extraction rate of the skin frog antibacterial peptide was measured as 2.528%.The physicochemical properties of the Rana chensinensis antibacterial peptides were tested.The aqueous solution of the peptides was scanned by UV at full wavelength to determine whether there were characteristic absorption peaks and impurity absorption peaks.Further experiments showed that the peptide was not found to have cytotoxicity and skin irritation at a concentration of 100 mg/m L.Subsequent stability experiments proved that it has good stability and can be used in subsequent experiments.The nanoemulsion blank system was screened by emulsifier titration,and the best nanoemulsion blank system was selected as follows: the oil phase was isopropyl myristate(IPM)with a concentration of 5.68% and the surfactant was polyoxyethylene glycol.Semen polyoxyethylene ether(EL-40),concentration 32.38%,co-surfactant 1,2-propanediol,concentration 10.79%,aqueous phase 51.15%.The preparation method is as follows: the oil phase,the water phase,the emulsifier and the coemulsifier are mixed in the beaker according to the above proportion,and magnetic stirring is performed for 30 minutes at room temperature,and the clear blank nanoemulsion can be observed at this time.By studying the physicochemical properties,the blank nanoemulsion is an O/W nanoemulsion with an average particle size of 72.3 nm and a potential value of-55.01 m V,which has good stability and no skin irritation.Therefore,the nanoemulsion containing 0.25% Rana sylvatica antibacterial peptide was prepared with the blank nanoemulsion system as the carrier,and the average particle size was 113.9 nm,and the stability was good.Using a single-factor optimization experiment,the appearance,reconstitution time,and freeze-dried loss rate were used as indicators to optimize the preparation process of freeze-dried powder containing Rana pallidum peptides.The best freeze-drying process was determined as: 4% of the freeze-dried protective agent Glycine +1% mannitol,Rana sylvatica antibacterial peptide 0.25%,freeze-dried volume 1.2 m L,freeze-drying time 20 h.In this experiment,the biological activity of peptides can be greatly preserved by preparing freeze-dried powder of Rana sylvatica antibacterial peptide,and the antibacterial effect of the product after lyophilization is good.In this experiment,Rana sylvatica peptides were used as the main raw materials to establish a nano-emulsion containing Rana sylvatica peptides and preparation process of Rana lyophilis polypeptide lyophilized powder.The aim was to apply it to superficial skin injury groups and hope to prevent infection after cosmetic trauma,and quick fix to provide a good product.