关键词: 氯硝柳胺乙醇胺盐, 喷雾剂, 牛, 血吸虫病, 尾蚴

Abstract:

Objective To develop a spray of niclosamide ethanolamine salt for prevention of bovine from Schistosoma japoni? cum infection, and explore its characteristics and effect. Methods The solubilizers, penetrating agents, emulsifiers were screened, and the spray of niclosamide ethanolamine salt was formulated according to the screening results. The niclosamide etha? nolamine salt was determined by using a HPLC technique, and the stability was observed. The preventive effect of the spray was as? sessed by in?vitro trials against cercariae and protection trials in mice. Results The screened formulation was presented as follow? ing: 1% niclosamide ethanolamine salt was dissolved in 18% dimethyl sulfoxide, and then added with 1% azone and 2% span, to? gether with 78% ethanol, to yield a 1% spray of niclosamide ethanolamine salt. The spray appeared golden flowing liquid, with 1% niclosamide ethanolamine salt in content (W/W), pH 7.4-7.8, and good thermal and cold stability. All cercariae died (100%) while exposed to the spray at a concentration of 1.00 mg/L for 2 min, and the similar effect was achieved while exposed to 0.50 mg/L of the spray for 5 min or 0.10 mg/L for 30 min. The spray at concentrations less than 0.05 mg/L had no evident toxicity to cercariae. A volume of 0.5 ml of the 1% spray was sprayed on the abdomen of mice, 1-3 d later, the mice were infected with S. japonicum cercar? iae on the spraying sites, no mice were infected, with a protection rate of 100%. Five days post?spraying, the protection rate was 40%, and the worm burden reduction rate was 65.87%. Ten days later, all the mice were infected, however, the worm burden reduc? tion rate was 51.98%. The worm burdens on days 5 or 10 post?spraying were significantly lower than those of the control (P < 0.01).The spray exhibited a good preventive efficacy to mice from S. japonicum infection in lab. Conclusions The spray of ni? closamide ethanolamine salt has stable physical and chemical property, and is a novel liquid preventive agent against bovine schistosomiasis. In addition, it has a rapid activity against S. japonicum cercariae, so can prevent bovine from S. japonicum in? fection.

Key words: Niclosamide ethanolamine salt, Spray, Bovine, Schistosomiasis, Cercaria