Compound Of Botanical Bactericides And Its Preparation Of Microemulsion

As single botanical bactericide had high development cost and poor antibacterialproperty, the study on compound botanical bactericides indicated that it couldeffectively use existing plant resources, reduce costs and expand the broad-spectrumantimicrobial properties of botanical bactericides, even improve bactericidalproperties. In this paper, garlic oil, clove oil, cinnamon oil, ginger oil, forsythia oil,sophora flavescens extract, honeysuckle extract and rhubarb extract with goodbactericidal properties were selected by references. Escherichia coli andStaphylococcus aureus were chosen as tested bacteria; the minimum inhibitoryconcentration (MIC) of each drug and two combined drugs were tested byMueller-Hinton agar dilution method; then calculated the fractional inhibitoryconcentration index (FIC) and determined the interactions between drugs. The resultsshowed that for Escherichia coli and Staphylococcus aureus, the bactericidalproperties of the essential oils were better than that of plant extracts and bactericidalproperties sequence from good to bad was garlic oil≈cinnamon oil> clove oil>ginger oil> forsythia oil> honeysuckle extract> sophora flavescens extract> rhubarbextract. The combination of clove oil, cinnamon oil and garlic oil had an additiveeffect on Escherichia coli and Staphylococcus aureus, and the best compound ratiowas8:8:1. And the combination of sophora flavescens extract, rhubarb extract andhoneysuckle extract had a synergistic effect on Escherichia coli and Staphylococcusaureus and the best compound ratio was5:4:8.The compound oil microemulsion was prepared by using clove oil, garlic oil andcinnamon oil (mass ratio is8:8:1) as oil phase, Tween80and OP-10as surfactant,glycerol, n-butanol and n-pentanol as cosurfactant, and distilled water as water phase.The paper investigated the influence of surfactant, cosurfactant, Km, oil phase,temperature and stirring time on the microemulsion formation through the analysis ofthe pseudo ternary phase diagram microemulsion area, the diameter andpolydispersity index of microemulsion. The results showed that the optimum formulaof microemulsion was compound oil as the oil phase, Tween80as the surfactant,glycerol as the cosurfactant, distilled water as the water phase, Km=5:1, the massratio of the oil phase and the mixed surfactant was2:8. Thus the concentration of dissolved oil was largest and comprehensive performance was best.The property of microemulsion was an important indicator. The physicalproperties such as size, pH, viscosity and concentration were detected by Malvernnano-sizer, fine pH meter, rotating viscometer and UV spectrophotometer; thestability was evaluated by centrifugation, salinity test, NaOH neutralization, lowtemperature and long-term experiments. The results showed that the compound oilmicroemulsion was clear and transparent liquid. The average diameter was13.4nm,pH=5.70, the average content of eugenol was25.04mg/ml. The presence of salt ionshad a negative effect on the microemulsion system and microemulsion system hadbetter stability under the condition of alkalinity, low temperature and long-termstorage. The microemulsion had an inhibitory effect on Escherichia coli andStaphylococcus aureus, according with the characters of microemulsion and thedemands to the antibacterial activity.