Abstract: Objective In order to make the anaesthetic-pentobarbital that has been using on laboratory animals in domestic to meet international standard, established the preparation method for non-pharmaceutical grade sodium pentabarbital; Evaluated anesthetic effect of SD rat for three different solvent formulations. Methods Three different solvent systems were formulated 30mg/ml and 50 mg/ml pentobarbital sodium injection respectively, and tested dissolubility, pH, Conc. and the stability stored at room temperature and 2 ~ 8 ℃ of each pentobarbital sodium injection; Pentobarbital preparation with three different solvent are injected in SD rats, colleted valid duration of anesthesia and anesthetic state to evaluate anesthatic effection. Result The dissolubility of pentobarbital is great when prepared by Ethanol-Propylene glycol and HS15; The pH is stable on 9.6±0.2; the solution is very stable at room temperature and 2~8 ℃ during 30 days; For anesthetic effect evaluation of pentobarbital sodium injection in SD rats, the ethanol- propylene glycol group has short anesthesia time, minor individual differences, and the most animals reaching up to the ideal anesthetic effect. Conclusion The ethanol-propylene glycol as a solvent for the solubility and stability of the non-pharmaceutical grade sodium pentobarbital are very good, meanwhile it has the best animal anesthetic effect; the HS15 group followed.

Key words: Pentobarbital, Preparation, High performance liquid chromatography(HPLC), Anaesthesia