The Preparation Of Liposomal Gel Of Nano-silver And Its Quality Evaluation And In Vitro Antimicrobial Aclivily And Safety Evaluation

Objectives To use the best antimicrobial activity of nano-silver, nano-silver can bemade liposomal gel. At the same time, the stability of the nano-silver in the gel andthe compliance of the use procedure were improved. So the gel can be used to treatthe disease of skin by pathogenic bacterium.Methods The content determination method of nana-silver was established by flameatomic absorption spectrophotometer, with the silver standard solution as thereference substance. Take the entrapment efficiency as the investigation index,selected the optimum dosage of lecithin and cholesterol and other influencing factors.The best prescription of chitosan and glycerol in the nano-silver liposomal gel was bechose with the pH and the accumulate release rate of12h in vitro as the theinvestigation index. On the basis of the above two points, the best prescription ofchitosan, glycerol, peppermint oil, lecithin and cholesterol and the preparationprocess conditions were selected by orthogonal test and the accumulate release rate of12h in vitro. Evaluate the quality of the homemade nano-silver liposomal gel byconsulting the relevant provisions of “Chinese Pharmacopoeia”(2010version).Thedosage of nano-silver in the homemade gel was confirmed by minimal inhibitoryconcentration (MIC) and minimal bactericidal concentration (MBC) which weredetermined by the broth dilution method, at the same time, the antibacterial andbactericidal activity were proved by determining the antibacterial and bactericidal rate.The skin hypersensitive test was carried out on the intact and abraded skin of rabbits,and to investigate the accumulation and distribution conditions of nano-silver in ratsby using the preparation singe-dose and multiple-dose on the skin of rats.Results The average content of nano-silver by using the flame atomic absorption spectrophotometer was202.3μg/mL, the average recovery rate was92.4%～105%,RSD was3.4%, it showed that the determined results were accurate and reliable. Theprescription which was confirmed by the test was soybean lecithin (g): cholesterol (g)=0.30:0.05,0.3g of chitosan,1.5g of glycerol,0.15mL peppermint oil and5.10mLnano silver solution. The in vitro antibacterial test showed that, against theStaphylococcus aureus, E.coli, White beads coccus and P.aeruginosa, the MIC were0.80,1.59,0.80,3.17μg/mL, the MBC were6.33,3.17,50.60,25.30μg/mL. So todetermine the content of nano-silver in the liposomal gel should be50.60μg/mL, itmeans that to make sure the homemade gel was effective against the above four kindsof microorganisms. The results of quality evaluation: the characteristic was white orlight yellow emulsion thick liquid, pH was between5.50and6.00, the viscosity wasbetween200and230mPa·s, the content uniformity, granularity and microbial limitconformed with the regulations, the stability was good. The result of contentdetermination was28.60μg/mL, the recovery rate was96.2%～102%, RSD was1.7%, it showed that the determined results were accurate and reliable. Theantibacterial and bactericidal rates of the homemade gel were100%that against theEscherichia coli for2min, and the antibacterial and bactericidal rates of thehomemade gel were100%that against the other three kinds of microorganisms for2min, and the gel was harmless to skin of rabbits. After using the preparationsinge-dose and multiple-dose on the skin of mice, some amount of silver could bedetected in the hearts, livers, spleens, lungs and kidneys of mice in2-14d, and thecontents of silver in the spleens were highest, after30d, the contents of silver wereback to the normal level, and there was no accumulation phenomenon.Conclusions The article optimized the formulation and preparation process of thenano-silver liposome gel through tests, made the nano-silver as the liposome gel withgave full play to improving the stability of liposome and the sustained release effect of gel. And the accumulate release rate was40.9%of12h in vitro, thus it can be seenthe the homemade nano-silver liposome gel can release the nano-silver adequately.The antibacterial and bactericidal rates of the homemade gel were100%that againstthe four kinds of microorganisms for10min, it stated that the homemade gel has thebroad-spectrum antimicrobial activity. And the homemade gel was nonirritant toskins of rabbits, there was no accumulation in rats after doses through the skin, itprompt the the homemade gel was safe and effective as a preparation used on skin,and provides for the clinical a new therapu pathway.