Preparation Of Florfenicol Microemulsion And Treatment On Cows Mastitis

The purpose of this study was to prepare a high encapsulation efficiency, stability, safety, efficiency florfenicol nanoemulsion and to study the treatment on cows mastitis.1.Preparation of florfenicol nanoemulsionThis experiment used ethylene oxide hydrogen castor oil (RH-40), Tween-80, Span-80 as surfactant; using n-butanol, propylene glycol, glycerin, anhydrous alcohol as aid-surfactant; using liquid paraffin, soybean oil, nutmeg acid isopropyl (IPM), ethyl acetate, castor oil, glacial acetic acid as oil phase to prepare blank nanoemulsion. The nanoemulsion was evaluated by drawing artifical three initiatives phase diagram, and to study the effect of surfactants, aid-surfactant, oils, water and Km on the area of nanoemulsion forming, and Combining origin7.5 software analysis, screening the best drug-loading formula.The results indicated that using Tween-80/glycerin/acetic ester/distilled water, the area of the nanoemulsion was maximum, So that, Tween-80/glycerin/acetic ester/distilled water was selected as the prescription of florfenicol nanoemulsion.2.The physico-chemical property of florfenicol nanoemulsionBy using transmission electron microscope, laser particle size distribution instrument to investigate the physical and chemical properties. The results showed that florfenicol nanoemulsion was yellow, examination homogeneous, transparent, fluent fluidity and visible light blue light liquid, its average particle size was (30+5) nm, the Size distribution was narrow and evenly, compling with the requirements of nanoemulsion.3.The stability of florfenicol nanoemulsionThe content of florfenicol was measured by ultraviolet spectrophotometer, and through centrifugal test, hot stability test, accelerated testing and illumination experiment investigated its stability. The results showed that florfenicol had the maximal absorption in 254nm,it had a good linear range in 1μg/mL～50μg/mL, its average recovery was 98.3%, RSD was 0.41%, the average encapsulation efficiency was 88.08±0.22%. This method can be used to determinate the encapsulation efficiency and the content of florfenicol nanoemulsion, the appearance and content of nanoemulsion did not change obviously.4.The safety evaluation of florfenicol nanoemulsionThe safety of florfenicol nanoemulsion was evaluated by acute toxicity on mice, skin irritation and eye irritation experiment on domestic rabbits. The results showed that the accmumulation LD50 of the florfenicol nanoemulsion test on mouse was 1949.8 mg/kg. The stimulation to the skin and eyes of domestic rabbits were all nontoxic.5.Antibacterial effect in vitro of florfenicol nanoemulsionThis experiment selected three common pathogenic bacteria causing cows mastitis easily, and the antibacterial activity in vitro of the nanoemulsion was tested by tube double dilution method. The results showed that the minimal inhibitory concentration and minimal bactericidal concentration of the florfenicol nanoemulsion to the florfenicol solution was 1/2 for Escherichia coli and Streptococcus agalactiae in vitro; the minimal inhibitory concentration and minimal bactericidal concentration of the florfenicol nanoemulsion to the florfenicol solution was 1/4 for Staphylococcus aureus in vitro.6.The treatment of florfenicol nanoemulsion on cows mastitisBy measuring the somatic count (SCC) in milk of before and after the treatment of cow mastitis showed the florfenicol nanoemulsion on cow mastitis treatment was obviously superior to florfenicol solution.Cows breast perfused 50 mL florfenicol nanoemulsion, 1 times a day,and continuous perfused 8 days, had a good curative effect on cows mastitis.