1. Chemical properties Avermectins (AVMs) are a broad-spectrum antiparasitic drug. Its representative drugs are ibcidin (ABA) and Ivermectin (1VR).
AVMs have high molecular mass and sugar chain, basically weak polar substances, very low water solubility, poor solubility in saturated hydrocarbon solvents, and are easily soluble in most polar solvents. AVMs are white crystalline powders with a melting point of 155-157~C.
ABA and IVR are quite stable at ambient temperature, protected from light, sealed or pH 5-9. Strong base and acidic conditions should be avoided in the analysis.
2. Pharmacology and Toxicology
IVR and ABA are currently used as anti-parasitic drugs in veterinary clinical use, mainly for the treatment or prevention of parasitic nematodes and arthropod infections.
There was no significant difference in the metabolism of various AVMs in animals. Oral, subcutaneous or intramuscular injection can be quickly absorbed, widely distributed in the body, mainly in the original form with feces, a small amount excreted by the kidneys, also excreted with the milk. The concentration of zui in the liver tissue is high and the zui is slow, followed by fat, and the brain tissue is low. IVR is excreted slowly in the body, the duration of the conventional injection type is more than 14 days, and the duration of the sustained release preparation can be several months.
The toxicity of AVMs needs further study.
Second, the method of measurement
AVMs have high molecular mass and lack of significant analytical groups. The residual analysis process is more complicated. More and more solid phase extraction is used in sample processing. The main method is HPLC-based HPLC method. Immunoassays and HPLC/MS confirmation techniques have also evolved considerably.