Determination of the Concentration of Sinoacutine and Its Pharmacokinetic Study in Rabbits / 中国药房

ABSTRACT

OBJECTIVE： To establish a method for concentration determination of sinoacutine in rabbit plasma， and to conduct its pharmacokinetic study. METHODS： The rabbits were grouped according to gender， 6 rabbits in each group. Rabbits were injected with sinoacutine solution （5 mg/kg） via ear vein. Each blood sample 1 mL was collected before medication and 5， 10， 15， 30， 45， 60， 90， 120， 180， 240 min after medcation. After the plasma isolated and extracted with ethyl acetate， HPLC method was adopted by using sinomenine as internal standard. The determination was performed on Agilent Zorbax Extend-C18 column with mobile phase consisted of methanol-2 mmol/L disodium hydrogen phosphate aqueous solution （containing 0.016％ triethylamine， pH 9.8） （45 ∶ 55， V/V) at the flow rate of 1 mL/min. The detection wavelength was set at 262 nm， and column temperature was 30 ℃. The sample size was 20 μL. The pharmacokinetic parameters were calculated by using DAS 3.0 software. The difference of 2 groups were investigated by t-test. RESULTS： The linear range of sinoacutine were 0.1-5.0 mg/L； the limit of quantitation was 0.1 mg/L， and the lowest detection limit was 0.08 mg/L. RSDs of intra-day and inter-day were both less than 10％； the accuracy ranged from （99.80±8.21）％-（103.61±8.55）％. The extraction method did not affect the quantitative analysis of the substance to be measured. The average plasma-time curve of sinomenine with single intravenous injection in rabbits was in line with the two-compartment model. The distribution half-life of all rabbits was （10.99±2.52） min， and the elimination half-life was （147.08±32.41） min. AUC0-t was （190.82±30.82）mg·min/L， and AUC0-∞ was （289.82±73.27） mg·min/L. There was no statistical significance in pharmacokinetic parameters between female and male rabbits （P＞0.05）. CONCLUSIONS： Established HPLC method is simple， specific and sensitive， and can be used for plasma content determination of sinoacutine. Pharmacokinetic study shows that the pharmacokinetic process of the compound is in line with two-compartment model in rabbits. The pharmacokinetic parameters of the compound have no sex difference， and the compound is distributed rapidly and eliminated fast.