| Pochonia chlamydosporia(P.chlamydosporia)is an important egg-destroying fungus for biocontrol of parasites eggs,and is great potential in clinical practice,but there is still a lack of studies on its mechanism of action and preparations,which greatly hinders its application in veterinary practice.Therefore,based on the current situation of China,in order to develop an efficient biocontrol agent for parasites and improve the control effect of Pochonia chlamydosporia on parasites,the preparation of eprinomectin nanoemulsion were to be optimized,then the Pochonia chlamydosporia spore suspension was prepared followed by the combination preparation of EPR-NE and Pochonia chlamydosporia spore suspension was prepared.Lastly,the pharmacokinetics of the combination preparation was determined.The main results were as follows:(1)Pochonia chlamydosporia was highly invasive to Ascaris suis eggs,Coccidia oocysts,Fasciola hepatica eggs,and O.equi eggs.(2)Firstly,systematic optimization was carried out to the formulation of EPR-NE oral preparations.It was known that the best oil phase was ethyl acetate,and the best surfactant(emulsifier)was Tween-80,while the best co-surfactant(co-emulsifier)was anhydrous ethanol.The best ratio of surfactant to co-surfactant was 1:6.Finally,it was confirmed that the formula of eprinomectin nanoemulsion was 10% ethyl acetate,70% water,20% emulsifier(Tween 2.8%,anhydrous ethanol17.2%),and the staining method showed that EPR-NE was oil-in-water type.The spore suspension of EPR-NE was stable and the spore could germinate.(3)The suspension of EPR-NE-Pochonia chlamydosporia spores was administered to sheep by oral at a dose of 0.2 mg/kg body weight,and the EPR concentration in the blood reached the maximum at 12.3 h,which was 22.17 ng/m L,and the area under the curve was 687.42 ng·h/m L,while the elimination half-life of the drug in the blood was 12.15 h.The clearance rate was 300.19 m L/(h·kg),and the average residual time was 25.84 h.All thse showed that the absorption and metabolism rates of oral preparations were faster than pouring agents.The study finally determined the formula of eprinomectin nanoemulsion,and EPR-NE-Pochonia chlamydosporia spore suspension was successfully prepared,which can provide a new methode for the future prevention and control of parasites by biocontrol.So it has important application value and practical significance to the animal husbandry industry. |
