Determination Of Landiolol In Human Plasma And The Pharmacokinetic Study Of Landiolol Hydrochloride In Healthy Chinese Volunteers

PURPOSEThe quantitative analytical method of landiolol in human plasma is establishedbased on high performance liquid chromatography tandem mass spectrometry（HPLC-MS/MS）. The human plasma samples are collected during and aftercontinuous infusion of landiolol hydrochloride to the healthy Chinese volunteers andthe concentration of landiolol in human plasma is determined. The concentration-timecurves are drawed and the pharmacokinetic parameters are calculated. Thepharmacokinetic characteristics of landiolol of the healthy Chinese volunteers areevaluated for the II^IV clinical trials and market of hydrochloric landiolol injecta.METHODThe quantitative analytical method of landiolol in human plasma is establishedbased on HPLC-MS/MS. With the addition of pyridostigmine bromide to stabilizelandiolol, and bisoprolol as the internal standard, the plasma samples were subjectedto liquid-liquid extraction with diethyl ether:dicholoromethane （3:2, v:v） prior toassay by liquid chromatography-tandem mass spectrometry. Separation wasperformed on a TC-C18column （150×4.6mm,5μm） using a mobile phase ofmethanol:10mM ammonium acetate containing1%formic acid （65:35, v:v） in a runtime of only3.5min. Detection involved electrospray ionization in the positive ionmode followed by multiple reaction monitoring of the precursor-to-product iontransitions of landiolol at m/z510.1�'157.2and bisoprolol at m/z326.3�'116.1. Themethod was linear over the concentration range0.5-500ng/mL with a lowest limit ofquantitation of0.5ng/mL. The validation of method is fully progressed according with State Drug and Food Administration （SFDA） guidance.The recruitment of12healthy subjects was randomly divided into3groups of4in accordance with the Helsinki Declaration and GCP requirements. The humanplasma samples are collected during and after continuous infusion of landiololhydrochloride to the healthy Chinese volunteers and the concentration of landiolol inhuman plasma is determined. The concentration-time curves are drawed and thepharmacokinetic parameters such as peak plasma concentration （Cmax）, peak time（Tmax）, half life （t1/2）, mean residence time （MRT）, area under plasmaconcentration-tme curve （AUC0�'t）, area under plasma concentration-tme curve（AUC0�'∞）, clearance （CL）, and apparent volumn of distribution （Vd） are calculated inorder to evaluate the pharmacokinetic characteristics of landiolol of the healthyChinese volunteers.RESULTSThere are no peaks of the endogenous and exogenous interference at the locationof landiolol and bisoprolol on the chromatography. The method was linear over theconcentration range0.5-500ng/mL with a lowest limit of quantitation of0.5ng/mL,whose accuracy, intra-and inter-precision were less than±20%. Intra-and inter-dayprecisions （as relative standard deviation, RSD） of quality control samples of low,middle, high concentration were less than±15%, respectively, with accuracy （asrelative error, RE） less than±15%. The recoveries of landilol of the plasma samples oflow, middle, high concentration and bisoprolol were97.22±2.00%,100.06±2.88%,102.61±0.87%and101.73±1.96%, respectively, which were high and stable. Thematrix effects of landilol of the plasma samples of low, middle, high concentrationand bisoprolol were100.53±3.85%,98.17±0.54%,96.35±1.09%and98.58±2.36%,respectively. The matrix effects would not affect the determination of landiolol. Theplasma samples stored at room temperature for4h, and repeated freezing and thawingthree times, stored at-80℃for60d and plasma samples after treated stored at for4hat room temperature were stable, the accuracy less than±15%. The accuracy andprecision of the plasma samples after diluted were less than±15%. The results aboveshow that, the quantitative method of landiolol in human plasma, which is rapid, sensitive, accurate, precise, reliable, can be applied to the clinical pharmacokineticstudy of landiolol.The pharmacokinetic parameters of landiolol of the low, middle and high dosesare as follows:C_maxare244.25±31.73ng/mL,534.38±68.00ng/mL,1162.88±256.52ng/mL.Tmaxare0.56±0.35h,0.75±0.29h,0.63±0.34h. T_1/2are0.12±0.03h,0.15±0.039h,0.12±0.04h. AUC_0�'tare209.60±28.01μg/L·h,460.03±78.80μg/L·h,988.99±139.88μg/L·h. AUC0�'∞are210.12±28.02μg/L·h,461.59±79.35μg/L·h,991.23±140.51μg/L·h. CL are3.14±0.43L/h/kg,2.89±0.52L/h/kg,2.67±0.37L/h/kg. Vd are0.57±0.19L/h/kg,0.59±0.095L/h/kg,0.49±0.14L/kg.T_1/2of landiolol is very short. Landiolol is easily hydrolyzed by esterase inplasma. CL is high and Vd is less than the volumn of human fluid （36L）. Landiolol isexcreted rapidly and hard to store in tissues. During the doses in the research, C_max,AUC_0�'t, AUC0�'∞of landiolol increase with the dose increasing. The correlationcoefficient （r） are0.936,0.965,0.965, respectively, and P values are less than0.05,which mean C_max, AUC_0�'t, AUC0�'∞are linearly related to the dose. ANOVA testsresults show t_1/2、MRT、CL and Vd,whose P values are more than0.05, are notstatistically significantly different within doses. Non-parameter test results show Tmaxare not statistically significantly different within doses. In summary, landiolol has alinearly pharmacokinetic character.During the research, the subjects were not found any adverse reactions, andlandiolol showed good tolerability and safety.