Preparation And Pharmacodynamic Evaluation Of Natamycin Nanoemulsion

Objective: Natamycin nanoemulsion was prepared, then the quality, stability, safety,antifungal activity and clinical efficacy of natamycin nanoemulsion were evaluated, Whichprovided a experimental basis for natamycin nanoemulsion in the veterinary clinicalapplication.Method:(1) The formula of natamycin nanoemulsion were selected by protracting thepseudo-ternary phase diagrams, and then natamycin nanoemulsion was prepared by theformula. The structure type of nanoemulsion was determined by staining and dilution method.nanoemulsion drops was observed by Transmission electron microscopy(TEM). The particlesize distribution and Zeta potential were determined by Zetasizer Nano ZS analyzer. Thecontent of natamycin in natamycin nanoemulsion was determined by established UV-visiblespectrophotometer. Its stability was investigated by illumination experiment, acceleration testand long-term trial.(2) Determination conditions of natamycin content in nanoemulsion wereselected by UV-visible spectrophotometer, which established the analysis method fordetermination of natamycin nanoemulsion content.(3) The safety of natamycin nanoemulsionwas evaluated by acute toxicity test. The maximum tolerated dose of natamycinnanoemulsion on mice was determined by the maximum tolerated dose (MTD) test method,and the maximum tolerated dose multiple of chicken was calculated by formula, whichevaluated the safety of natamycin nanoemulsion.(4) With ketoconazole and terbinafine as apositive drug control, natamycin nanoemulsion and natamycin API on three kinds of subjectsstrains’ MIC were measured by Fungi in vitro susceptibility testing method M-27A, M-38P,Which was established by national committee for clinical laboratory standards(NCCLS), andinvestigated drugs fungicide performance.(5) Pathological models were established byinoculating Candida albicans perorally to the crops of chicken aritificially. The clinicalefficacy of natamycin nanoemulsion to the candidiasis of chicken was evaluated bycomparing the clinical efficacies of natamycin nanoemulsion with different concentrationsand natamycin API suspensions.Result:(1) According to the optimized prepared formula, the structure type of nanoemulsion was oil in water(O/W). The nanoemulsion drop presented as spherical shapewith a mean diameter of10.5nm(25℃) and zeta potential of+13.0mV (25℃, pH=3.5). Themean content of natamycin in natamycin nanoemulsion was17.31±0.02g/L. In lightlessconditions, the natamycin nanoemulsion had good stability and the period of validity was11months.(2) Selected319.4nm as detection wavelength. Good linearity of natamycin wasobtained in the range of5~40μg/mL. Established analytical methods of contentdetermination about natamycin nanoemulsion had good specificity, high recovery rate, goodrepetitiveness and precision.(3) Natamycin nanoemulsion was too lower toxicity to measureits median lethal dose(LD50), so determined the maximum tolerated dose(MTD), anddetermination of0.25mL/10g BW2times a day was the just dose that did not causing themice death. Natamycin nanoemulsion on chicken with the maximum tolerated dose multipleswas260times, which could be calculated by the MTD dose(>100).(4) Natamycinnanoemulsion for Penicillium, Candida albicans and Saccharomyces cerevisiae the MICvalue1,0.5,0.5μg/mL. Natamycin API, ketoconazole and terbinafine, respectively, for theMIC value of the three fungus2,1,1μg/mL,4,8,8μg/mL and1,8,16μg/mL. Natamycinnanoemulsion of the MIC values were less than or equal to the other three drugs. Three kindsof fungus in4μg/mL natamycin nanoemulsion for more than1.5h, did not grow. NatamycinAPI needed4μg/mL,2h in order to achieve the same effect. The ketoconazole andterbinafine, respectively, needed16μg/mL,4h and32μg/mL,4h.(5) There had no death ofchicken in natamycin nanoemulsion high and middle dose groups, and body weight wassignificantly higher than that in the natamycin suspensions group(P<0.05) and positivecontrol group(P<0.05),100%cure rate in both groups.Conclusion: The quality of natamycin nanoemulsion had achieved technicalspecifications of the nanoemulsion, and stable, safe, low toxicity. Ability of natamycinnanoemulsion to inhibit three kinds of typical fungi Stronger than natamycin API,ketoconazole and terbinafine. Natamycin nanoemulsion had significant efficacy for Chickencandidiasis, and is a promising new agents of natamycin for animal mycosis.