Studies On Preparation And Efficacy Of Compound Enrofloxacin Nanoemulsion

Obiective: to develop a compound enrofloxacin nanoemulsion, and studied the quality,safety, transdermal quality and availability of the compound enrofloxacin nanoemulsion. And also offered a new form for curing dog pyoderma.Methods:(1) The formula of the compound enrofloxacin nanoemulsion was determined by pseudoternary phase diagrams, and the oil was screened by solubility of enrofloxacin.(2)Quality evaluation of the compound enrofloxacin nanoemulsion: structure type was identified by staining; shape, particulate radius distribution and polydispersity index was examined by transmission electron microscopy and laser particle size analyzer; high performance liquid chromatograph was used to detedt its content; stability was determined by acceleration tests,light stability tests and temperature stability tests.(3)Safety evaluation of the compound enrofloxacin nanoemulsion: skin acute toxicity test, skin irritation test and skin allergy test was used to evaluate the safety of the compound enrofloxacin nanoemulsion.(4)Transdermal property of the compound enrofloxacin nanoemulsion in vitro: improved Franz diffusiing cells method was used to evaluate its transdermal property.(5)Bactriostasis of the compound enrofloxacin nanoemulsion in vitro: microdilution method was used to test minimum inhibitory concentration of bacteria, and compared with drug solutions.(6)Clinical trial of the compound enrofloxacin nanoemulsion: clinical efficacy was peformed on pyoderma dogs.Conclusions:(1)The formula of the compound enrofloxacin nanoemulsion: ENR 0.94wt%, CL 0.40 wt%, oleic acid 4.27 wt%, mixed surfactant TWEEN-20/2- Phenethyl alcohol(Km = 3∶ 1) 31.25 wt%,water 63.54 wt%;(2)the type of the compound enrofloxacin nanoemulsion was oil-in-water and it’s liquid was amber, transparent and clear, the drop of nanoemulsion presented spherical in transmission electron microscope, uniform distribution,mean grain size of the drop was 14.50 nm, and polydispersity index was 0.06, Zeta potential was-15.30 mV, with good stability and no delamination, flocculation and precipitation. The best determine wavelength of enrofloxacin and cefalexin in the compound enrofloxacin nanoemulsion was 271 nm, 262 nm, with good linear relation in the range of 6-100μg/ml.(3)There were no acute to toxicicity, obvious irritant, allergic reaction in the compound enrofloxacin nanoemulsion, so it’s a high safety skin drug.(4)transdermal osmotic rate of enrofloxacin in the compound enrofloxacin nanoemulsion and mixed drug solution was156.75±0.30665μg/cm2.h、107.58±0.90362μg/cm2.h, and transdermal osmotic rate of cefalexin in the compound enrofloxacin nanoemulsion and mixed drug solution was19.61±0.04834μg/cm2.h、13.574±0.07263μg/cm2.h, that means the transdermal property of compound enrofloxacin nanoemulsion significant better than mixed drug solution(P<0.01); The skin sections shows that ENR-CL-NE changed the structure of corneum and the permutation of ollagenous fiber, and inhanced the absorption of drugs in skin.(5)Bactriostasis of the compound enrofloxacin nanoemulsion in vitro: The MIC ofStaphylococcus aureus, staphylococcus epidermidis, Streptococcus agalactiae,Corynebacterium pyogenes was 0.125, 0.125, 0.5, 0.125 μg/ml; MBC: 2, 2, 4, 1 μg/ml. The result showed that the combination of enrofloxacin and cephalexin enhanced the bactriostasis activity.(6) Result of clinical trial showed the cure rate of compound enrofloxacin nanoemulsion better than other two external preparations.Conclusion: The compound enrofloxacin nanoemulsion prepared in this research satisfied the requirement of nanoemulsion formulation and had fine stability, safety and efficacy.