Preliminary Study On The Toxicity And Pharmacodynamics For Emulsion Of Dicyclanil In Pigs

Dicyclanil was developed by the Ciba-Geigy Company of Swiss and made it public in the 8th international conference on chemical pesticides.It is a new kind of insect growth regulator, of Cyano-pyrimidine. It was made a commodity by Ciba-Geigy Company of Swiss as spraying agent in 1998 named Clik. Dicyclanil kills Diptera by interrupting the larval development cycle as the maggots molt between instars, thus arresting the development of maggots before they mature to the critical pathological late instar stages that cause the serious damage to their host. To provid a guide for clinical medication, the toxicity about the crude drug of dicyclanil and the preliminary pharmacodynamics of topical emulsion of dicyclanil in pigs,has been investigated in this paper.1 Study on the toxicity of dicyclanilThe acute toxicity in mice by the oral route and in rats by the dermal route accumulative toxicity, sub-chronic toxicity, mutagenic toxicity and teratogenic toxicity of dicyclanil were been investigated in this experiment. Using modified Karber method to detect its acute toxic effect, finally get the data of median lethal dose (LD50) and the dose-mortality curve. Dose escalation method was used for detecting its accumulative toxic effect in mice, and tolerance test would be done soon after the accumulative toxic experiment being completed. With the high, medium and low-dose groups being set, added with the control group of organic solvent, the mice were given dicyclanil in distilled water containing 0.5% carboxymethylcellulose by oral consecutively for 28 days to evaluate the sub-chronic toxicity. The results showd that, the LD50 orally in the mice was 265mg·kg-1·bw-1, the 95% confidence interval was 235～297 mg·kg-1 and the LD50 dermally in the rats was 3380mg·kg-1·bw-1, the 95% confidence interval was 2990～ 3822mg·kg-1·bw-1.According to the toxicity grading standards of exogenous chemicals, this agent was actually mid-toxic drug. No mouse died during the period of accumulativetoxicity test, and the accumulation coefficient K was greater than 5, which showed that dicyclanil in the mice was mild. Tolerance test showed that the test group of mice had produced a certain tolerance to dicyclanil. Sub-chronic toxicity test showed that: the high-dose group of mice exposed some mild symptoms of poisoning such as piloerection, hunched posture, and dyspnoea. No mouse died during the trial period.The index of blood routine and blood biochemical showed that:dicyclanil had a certain impact on the function of liver and kidney in mice. The pathological histology results showed that,mice in high-dose group exposed a slight inflammatory response in liver, the other groups had no significant pathological abnormalities. The results of mouse sperm deformity and bone marrow micronucleus tests were all negative, indicated that dicyclanil was non-mutagenic toxic to mice. The results of teratogenic experiment to SD rats showed that dicyclanil had a certain teratogenic toxicity.Dicyclanil has some certain toxicity.2 Preliminary study on pharmacodynamics of 5% emulsion of dicyclanil in pigs.The effect of 5% dicyclanil emulsion on the Lucilia sericata’s larvae or eggs were evaluated in this paper. Four groupes of Cross-bred Duroc pigs were applied 5% emulsion of dicyclanil as a pour on formation.The doses were 100mg·kg-1·bw-1 45mg·kg-1·bw-1,30mg·kg-1·bw-1,0mg·kg-1·bw-1 respectively.Larvae or eggs of Lucilia sericata are placed in a small wound on the skin with the aim of creating an artificial strike. The individual sites are inspected at approximately 24,48 and 72 hours after the implanting of the eggs or larvae to assess the viability of the developing strike. The viability for each implant on individual pig was graded and recorded by a assessment procedure,the larvae impants were performed every two weeks.The results indicated that the 5% emulsion of dicyclanil could provide complete protection to at least 8 weeks after treatment for all the treated groups.After week 8th, the efficacy started to decline,and the low-dose group lost its effection at 12th week,the high(100mg·kg-1·bw-1)and the middle group(45mg·kg-1·bw-1) lost effection at 14th week.