| Slight scratches,bruise,cuts and burns on skins are common in our daily lives.At present,using bandage for small bleeding wound on the superficial skin is universal by covering the wound and isolating the influence from the environment.It is inconvenient because of its poor permeability and poor waterproofness.Ordinary bandage limits flexibility in some complicated sites(such as the body joints and skin wrinkles)and special shape of the wound resulting in adhering on surface of the wound unevenly.Smearing or spraying liquid wound dressing has emerged in recent years.It can protect the wound by means of forming a protective film but is not conducive to wound healing because of poor waterproofness.Hence,this subject proposed to develop a liquid bandage to protect the wound to promote wound healing and prevent infection with excellent waterproofness and breathability.First of all,Japan’s Kobayashi Liquid bandage is chosen to be a benchmark on the basis of researches on the commercially available products.GC is used to analyze its solvents composition,measuring the usage amount of isopropyl alcohol is 35.1%,ethyl acetate is 21.4%,butyl acetate is 5.3%,exactly the proportion is 6.6:4:1.HPLC is also used to analyze the content of benzyl alcohol and tocopheryl acetate,getting the result that the usage amount of benzyl alcohol is 4%,tocopheryl acetate is 0.06%.The formulation optimization of liquid bandage takes the mechanical properties of the film,waterproofness and breathability as evaluation index.Choosing the prescription of the liquid bandage and the best usage amount of each component,finalizing that the usage amount of nitrocellulose as film-forming material is 6%,castor oil as plasticizer is 4%,solvents composition composed of isopropyl alcohol is 43.77%,ethyl acetate is 28.70%and butyl acetate is 10.77%,tocopheryl acetate as antioxidant is 0.12%,clove oil and mint oil as corrigent is 0.1%.The liquid bandage prepared has good applicability,spreading property and presents colorless.The mechanical properties of the film obtained by liquid bandage present good results from the tensile strength exceeds 5.0Mpa and the breakpoint elongation percentage exceeds 165.00%.The liquid bandage also has good air permeability and waterproofness results from the water vapor permeability ratio for 24h exceeds 0.80 mg·cm-2·h-1and the the water loss ratio is less than 5.0%.All the indexes are better than Kobayashi liquid bandage.The pharmacological experiment of the liquid bandage is measured by the wound healing experiment of the total excision of the skin of mice via self-regulating liquid bandage,Kobayashi liquid bandage and Johnson&Johnson band-aid.,resulting in the self-regulating liquid bandage can promote the healing of the wound preferably and speed up the wound healing process significantly.The pathological section indicates that the skin of animal models restores good.The bacteria resistance test indicates that the self-regulating liquid bandage can prevent the serratia marcescens penetrating the film resulting in good bacteria resistance.The self-regulating liquid bandage has a significant antibacterial activity on staphylococcus aureus,pseudomonas aeruginosa and escherichia coli.The self-regulating liquid bandage has no toxicity to epithelial fibroblasts of mice and do not inhibit the proliferation of the cells via the biological compatibility experiments.The test of influencing factors indicated that the appearance,coating property,mechanical property,waterproofness and breathability of the liquid bandage have no obvious change after existing in hot and humid environment for 10 days.Various indexes of the self-regulating liquid bandage has no obvious change after accelerated testing and long-term experiment resulting in the self-regulating liquid bandage has a good stability.In the aspect of safety,the self-regulating liquid bandage do not produce skin irritation and skin allergy via the dermal irritation in rabbits and the dermal sensitivity test in guinea pigs,resulting in good safety. |
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