The Research Of Compound Centella Asiatica Cataplasm

Hypertrophic scar is an abnormal scar which is caused by hyperplasia of fibrous connective tissue and large amount of collagen deposition during skin injury and healing.The local tissues where wound is healing caused by skin burn and surgical trauma tend to become hyperfibrotic and lead to scar formation.Centella asiatica and Aloe vera gel can activate the epithelial cells,promote granulation tissue,inhibit proliferation of fibroblasts and scar formation.The effective combination of the two drugs can reduce scarring and promote the regeneration of skin.Gel patch,which reduces times of administration,is to apply hydrophilic gel matrix to non-woven fabric or other backing material,its paste is not only fine,but also greasy.Therefore,it is of great significance to prepare the compound centella asiatica cataplasm combining aloe vera and centella asiatica extraction.Stablished a UV method to determine centella asiatica,HPLC method to determine madecassoside and asiaticoside,they had high precision and sample recovery rate.We studied the optimum extraction process of centella asiatica through single factor experiment and orthogonal experiment.The optimum extraction process was as follows : the concentration of ethanol 70%,ratio of material to liquid 1:10,extraction time 3h,3 times.With optimum extraction process,the extraction rate of centella asiatica was 1.53%,the solvent purification rate was 6.8%,HPD100 resin purification rate was 72%(madecassoside was 48.13%,asiaticoside was 23.87%).With screening gel paste matrix,we choose sodium polyacrylate NP700 as gel matrix skeleton material,hydroxy aluminium as the crosslinking agent,glycerin for moisturizing factor,CMC-Na as tackifier,EDTA-2Na and tartaric acid as regulator,kaolin as filler.Single factor experiment confirmed the content range of NP700,glyoxal,glycerol and kaolin.On this basis,further using the response surface design experiment,to identify the best prescription matrix ratio,the optimum prescription matrix ratio was as follows: NP700: hydroxy aluminium: tartaric acid: glycerin: CMC-Na: EDTA-2Na: kaolin = 4.9: 2: 0.2: 37: 0.5: 0.05: 2(w/w).Based on the study of the properties,identification,inspection and content determination of the prepared preparation,the quality standard of compound centella asiatica cataplasm was preliminarily established.Under the optimal prescription,three batches were prepared,and it was found that this product was a light brown cataplasm by adhesion to white nonwoven fabric.The madecassoside and asiaticoside and aloe polysaccharide were identified.The examination of the plastic property and adhesion of the product conformed to the requirements of Chinese Pharmacopoeia(2015 Edition).Centella asiatica was 2.46g(madecassoside 1.69 g and asiaticoside 0.77g)and aloe polysaccharide was 0.25 g found in 100 g product,and labelled amounts was 98.4% and 101.32%.Compared self-made compound centella asiatica cataplasm and commercially available drug,self-made compound centella asiatica cataplasm released quickly.The study of release kinetics in vitro found that it conformed to the Higuchi model.The release mechanism was further invesitgated using the Ritger-Peppas model.We found diffusion and dissolution acted together to release the main ingredient.With 12 h cumulative transdermal amount,the dosage of the percutaneous promoter was set at 2%.Compared self-made compound centella asiatica cataplasm and commercially available drug,self-made compound centella asiatica cataplasm penetrated quickly.The study of transdermal kinetics in vitro found that it conformed to the zero-order model.Taking hyperplastic scar healing time and scar area as indexes,the scar healing results of the model group as reference,scar experiment in vivo was performed.The results show that the homemade drug for scar healing effect was superior to the commercially available drug,and aloe vera also effectively accelerate the scar healing time.