LC-MS/MS法测定大鼠血浆中他莫昔芬与其活性代谢物4-羟基他莫昔芬的浓度及其药动学研究

目的:建立大鼠血浆中他莫昔芬与其活性代谢物4-羟基他莫昔芬浓度的测定方法,并研究其在大鼠体内的药动学。方法:取大鼠8只灌胃给予他莫昔芬10mg·kg-1,检测给药前和给药后48h内他莫昔芬和4-羟基他莫昔芬的血浆浓度,并计算其药动学参数。采用液相色谱-串联质谱法,以维拉帕米为内标,色谱柱为PhenomenexGeminiC18,流动相为甲醇-0·025%甲酸水溶液(梯度洗脱),流速为0·25mL·min-1,柱温为40℃;电喷雾正离子源,他莫昔芬、4-羟基他莫昔芬和维拉帕米的选择检测离子质荷比(m/z)分别为372·3→129·1、388·4→128·9、455·3→165·0。结果:他莫昔芬和4-羟基他莫昔芬检测浓度的线性范围分别为1～500(r=0·9998)、0·5～50(r=0·9995)ng·mL-1,最低检测限分别为0·05、0·1ng·mL-1;药动学参数分别为t1/2β:(8·9±0·5)、(8·6±0·7)h,cmax:(112·2±39·2)、(31·1±5·6)ng·mL-1,AUC0～48h:(1501·1±213·8)、(431·2±31·8)ng·h·mL-1。结论:本方法专属性强、灵敏度高、准确性好,可用于他莫昔芬和4-羟基他莫昔芬的血药浓度测定。他莫昔芬和4-羟基他莫昔芬在大鼠体内的药动学符合一室模型特征。

Determination of Tamoxifen and Its Active Metabolite 4-hydroxytamoxifen in Rats Plasma by LC-MS/MS and Pharmacokinetics Study

OBJECTIVE:To establish the method for the concentration determination of tamoxifen and its active metabolite 4-hydroxytamoxifen in rats plasma,and to study its pharmacokinetic in rat.METHODS:8 rats were given tamoxifen 10 mg·kg-1 intragastrically,plasma concentration of tamoxifen and 4-hydroxytamoxifen were determined before and after administration and pharmacokinetic parameters were calculated.LC-MS/MS was adopted using verapamil as internal standard.Phenomenex Gemini C18 column was adopted with mobile phase consisted of methanol-0.025% formic acid solution(gradient elution) at a flow rate of 0.25 mL·min-1.The temperature of column was 40 ℃.Electrospray cation source was adopted.The ion of monitoring(m/z):372.3→129.1 for tamoxifen,388.4→128.9 for 4-hydroxytamoxifen and 455.3→165.0 for verapamil,respectively.RESULTS:The linear ranges of tamoxifen and 4-hydroxytamoxifen were 1～500 ng·mL-1(r=0.999 8) and 0.5～50 ng·mL-1(r=0.999 5),respectively.The lowest limits were 0.05 ng·mL-1 and 0.1 ng·mL-1.Pharmacokinetic parameters of tamoxifen vs.4-hydroxytamoxifen were as follows:t1/2β:(8.9±0.5) h vs.(8.6±0.7) h;cmax:(112.2±39.2) ng·mL-1 vs.(31.1±5.6) ng·mL-1;AUC0～48 h:(1 501.1±213.8) ng·h·mL-1 vs.(431.2±31.8) ng·h·mL-1.CONCLUSION:The method is specific,sensitive and accurate,and it is suitable for concentration determination of tamoxifen and 4-hydroxytamoxifen in plasma.The pharmacokinetics of tamoxifen and 4-hydroxytamoxifen in rats are up to the characteristics of one-compartment model.