| Objective:In this study,Mongolian dandelion was selected as the research object,and the optimal technology of extraction and boiling of the effluent was used to prepare dandelion band-Aids,and the content and uniformity of the band-Aids were measured.The permeability of the Band-aids was evaluated by in vitro percutaneous permeability test,and then the wound repair effect was studied.To provide scientific basis for further development of dandelion preparation for external useExperimental method: 1.Screening of water decoction extraction process of dandelion :L9(34)orthogonal test was carried out by HPLC method with chlorogenic acid content and extract rate of water decoction as indexes.In the process of water decoction extraction,the amount of water added × decoction time × decoction times were taken as three factors to screen out the best water decoction extraction process.2.Preparation of dandelion wound paste : According to the results of experiment 1,the dandelion extract was extracted by the best extraction process,and then the dose of wound paste was converted by the yield of extract,and the dandelion wound paste was prepared by layering method..3.Determination of content and content uniformity of dandelion wound paste :The chlorogenic acid standard and rutin standard were accurately weighed and added to methanol to constant volume to 5 m L constant volume bottle to configure the reference solution.The wound paste sample was about 0.16 g,and 50 % methanol was added to 10 m L conical bottle to be completely dissolved and filtered.The sample and the reference solution were injected into HPLC to determine the content of chlorogenic acid and rutin in the wound paste.On the basis of the content determination,the content uniformity of the dandelion wound paste was checked according to the requirements of the content uniformity in the general rule 0941 of the Chinese Pharmacopoeia 2020 edition.4.Percutaneous permeability test and wound repair effect :(1)A certain area of the wound was pasted on the side of the stratum corneum of the skin,fixed between the Ussing chamber instruments,the inside of the skin was facing the receiving pool,the water bath temperature was(37 ± 0.5 °C),and the receiving medium was normal saline.2ml samples were taken at 0.5h,1h,2h,4h,6h and 8h respectively and the same amount of medium was supplemented in time.After that,the osmotic solution at different time points was determined by HPLC.(2)The rats fed for seven days were randomly divided into six groups : normal group,model group(no administration),positive control group(Yunnan Baiyao wound paste),low dose administration group,middle dose administration group and high dose administration group.Except for the normal group,the rest of the rats were artificially made with a puncher on the back to create a wound with a unified depth of fascia.One hour after the wound was slightly contracted,the drug was administered.The positive group was given Yunnan Baiyao Chuangke Tie,and the model group was not given medicine.The back was wounded with medical tape for one week for single cage feeding,and the dressing was changed daily to complete healing.The wound changes of rats were observed daily.Calculate the wound healing rate;h E staining was used to observe the pathological symptoms of skin.Results:1.The single factor experiment was carried out by using L9(34)orthogonal experiment method.From the experimental results,the influence degree of each factor on the extraction effect was as follows : water addition > decoction time > decoction times.The best factor level was A3B3C2,that is,the water addition was about 20 times of the original medicinal material,the decoction time was 2h,the decoction times was 2 times,the best content was 1.35 %,and the extraction rate was 38.89 %.2.Through the layering method,the wound paste prepared with dandelion extract as the main drug and triketone as the auxiliary material has good adhesion and adhesion,moderate drug release,and its PH is within the range of 5-9.3.The average mass analysis of chlorogenic acid and rutin was 0.84 mg / g and 2.3 mg / g.The standard curve coefficient has good linearity;the RSD % of precision test,repeatability test and stability test were all less than 2 %.The recovery results were 99.5 % and 101.93 %,and the RSD % were 1.6 % and 1.1 %,respectively.The content uniformity of chlorogenic acid and rutin in three batches of samples was determined by the established method.The results showed that the average contents of chlorogenic acid in three batches of samples were 93.18 %,90.41 % and91.20 %,respectively,and the content uniformity L values were 7.0,9.8 and 8.9,respectively.The average contents of rutin were 95.45 %,93.84 % and 92.14 %,respectively,and the L values of content uniformity were 4.6,6.2 and 7.9,respectively.The results were in accordance with the general rule 0941 of Chinese Pharmacopoeia(L≤ 25.0).It shows that this method can determine the content uniformity of chlorogenic acid and rutin in dandelion wound patch.4.(1)In vitro percutaneous permeability experiment,the content of chlorogenic acid was zero at 0.5h,indicating that the drug was in the stage of sticking to the skin and releasing the drug.After 1h,it penetrated into the skin to achieve the therapeutic effect,reaching the highest concentration at 2 hours,and the content was 0.64 %.Then gradually decreased,but maintained a high content,6h began to stabilize at a higher content,indicating that it can play a long-term effect.(2)During the 18-day wound repair experimental cycle,the postoperative activity of the rats was normal,and the skin of the other groups except the model group was basically healed.Compared with the model group,the wound surface of the administration group was flat and the area of scab formation was small.The wound healing rate of the administration group was significantly improved within 1-18 days of administration,reaching 98 % at 18 days of administration.The results of HE staining showed that there were different degrees of healing in each group on the 7 th and 14 th days.Compared with the model group,the capillaries in the administration group were evenly distributed,there were more fibroblasts,and the inflammatory cells decreased significantly.On the 18 th day,the low-dose administration group and the positive control group were covered with complete skin,and more neovascularization was evenly arranged and a large number of hair follicles were generated while a large number of hairs were generated.Conclusion: Based on chlorogenic acid content and paste extraction rate as indexes,the optimal extraction process was as follows: the water added was about 20 times that of the original medicine,the decocting time was 2h,and the decocting time was 2 times.Meanwhile,the established quantitative analysis method has strong precision,repeatability and stability.The measurement results are reliable,and the content uniformity is within the specified range(L≤25.0).According to the wound healing rate and HE staining results,it can be concluded that the low-dose treatment group has a good degree of wound healing and a fast healing rate.This research provides a certain basis and scientific basis for the development of dandelion preparation for external use. |
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