血浆中去羟肌苷测定与制剂生物等效性评价

 目的建立测定人血浆中去羟肌苷的液相色谱-质谱/质谱联用法(LC-MS/MS),并应用于药物制剂生物等效性评价。方法18名中国健康男性志愿者单剂量随机交叉po200 mg去羟肌苷参比制剂和受试制剂,血浆样品经沉淀蛋白处理,通过LC-MS/MS测定其浓度,采用非隔室模型计算药动学参数和相对生物利用度,并对参数进行方差分析和双单侧t检验。结果LC-MS/MS测定血浆中去羟肌苷的线性范围为5.0～2 000μg·L^-1,定量下限为5.0μg·L^-1。日内、日间精密度(RSD)均小于6%,准确度(RE)在±4%之内。应用本法测得18名中国健康男性志愿者po 200 mg去羟肌苷参比制剂后主要药动学参数为:t_max为(0.65±0.30)h,ρ_max为(1 052±353)μg·L^-1,t_1/2为(1.53±0.38)h,用梯形法计算,AUC_0-t为(1 628±479)μg·h·L^-1,服用受试制剂后主要药动学参数为:t_max为(0.47±0.13)h,ρ_max为(1 090±531)μg·L^-1,t_1/2为(1.44±0.46)h,AUC_0-t为(1 520±661)μg·h·L^-1。以AUC_0-t计算相对生物利用度为(95.8±20.8)%。结论该法灵敏、快速、准确,操作简便、线性范围宽,适用于去羟肌苷制剂的生物等效性评价。

Determination of Didanosine in Human Plasma and Its Application to a Bioequivalence Study

OBJECTIVE To develop a sensitive and specific LCMS/MS method for the determination of didanosine in human plasma and to study the bioequivalence of different formulations containing didanosine.METHODS After a simple protein precipitation using acetonitrile,the samples were analyzed by liquid chromatography-tandem mass spectrometry.The pharmacokinetic parameters of didanosine in two formulations were calculated by non-compartment analysis.RESULTS The linear calibration curves were obtained in the concentration range of 5.0～2 000 μg·L^-1.The intra-and inter-day relative standard deviations(RSD) over the entire concentration range were less than 6%.Accuracy(RE) determined at three concentrations was within ±4%.Pharmacokinetic parameters for the reference formulation were obtained as follows: t_max was(0.65±0.30) h,ρ_max was(1 052±353) μg·L^-1,t_1/2 was(1.53±0.38) h,AUC_0～t was(1 628±479) μg·h·L^-1.Pharmacokinetic parameters for the test formulation were obtained as follows: t_max was(0.47±0.13) h,ρ_max was(1 090±531) μg·L^-1,t_1/2 was(1.44±0.46) h ,AUC_0～t was(1 520±661) μg·h·L^-1.The relative bioavailability of the test formulation to the reference was(95.8±20.8)%.CONCLUSION The method is sensitive,rapid,robust,and is proved to be suitable for bioequivalence evaluation of formulations containing didanosine.