高效液相色谱法测定奥美拉唑血药浓度及其药代动力学

建立了用反相高效液相色谱法测定血浆中奥美拉唑含量的分析方法。该分法采用液相提取预处理血样,在25～2000 ng/ml的浓度范围,线性关系良好,最低检测浓度4 ng/ml,奥美拉唑的相对回收率(98.07±5.21)％,日内变异<3.0％,日间变异<8.5％。并且,应用本法对正常人静脉推注奥美拉唑进行了药代动力学研究。     

奥美拉唑胶囊人体药代动力学及相对生物利用度研究

目的 :测定奥美拉唑胶囊的药代动力学及相对生物利用度。方法 :18名志愿者单剂量随机交叉口服40mg 奥美拉唑胶囊和洛赛克胶囊 (对照品 )后 ,经高效液相色谱法测定血药浓度。结果 :口服奥美拉唑胶囊或洛赛克胶囊后 ,血药浓度达峰时间分别为 (2 10±0 64)h和 (1 88±0 70)h ,峰浓度分别为 (895 64±553 07)ng/ml和 (974 67±554 93)ng/ml,曲线下面积分别为 (1971 88±1220 98)ng/(h·ml)和 (2057 60±1306 32)ng/(h·ml)。结论 :奥美拉唑胶囊与洛赛克胶囊相比较 ,具有生物等效性。     

血清PSA值及直肠指检指导前列腺穿刺活检的临床意义

目的 探讨血清PSA浓度及直肠指检在指导前列腺穿刺活检中的价值.方法 对59例血清PSA＞4 ng/ml和(或)直肠指检前列腺有结节的患者,行经直肠B超引导下前列腺穿刺活检.结果 59例患者中前列腺活检阳性者32例(54%),PSA浓度＞10 ng/ml组活检阳性率较PSA＜10 ng/ml组高(P＜0.05).直肠指检发现有结节的患者,前列腺活检阳性率较无结节明显增高(P＜0.05).结论 随着血清PSA浓度升高,前列腺活检阳性率升高;对于直肠指检发现有结节患者,即使PSA＜4 ng/ml,也应行前列腺穿刺活检排除前列腺癌.     

用中空纤维液相微萃取-HPLC法测定人血浆中酒石酸美托洛尔的浓度

目的:建立中空纤维液相微萃取-HPLC法测定人血浆中酒石酸美托洛尔的浓度.方法:优化酒石酸美托洛尔液相微萃取法供给相和接受相的浓度、萃取时间、萃取温度、萃取转速和离子强度,血浆样品经中空纤维液相微萃取法萃取后,用HPLC法测定酒石酸美托洛尔的浓度.色谱柱:Agilent Zorbax Eclipse XDB-C18柱,流动相:甲醇-0.1％磷酸(40∶60),流速:1 ml/min,激发波长:227 nm,发射波长:305 nm,柱温:30℃.结果:酒石酸美托洛尔在2～ 125 ng/ml线性关系良好,低、中、高三种浓度(5、20、100 ng/ml)的日内、日间精密度均＜10％,回收率分别为(87.1±7.3)％、(92.6±5.8)％和(89.1±2.5)％.结论:中空纤维液相微萃取-HPLC法适用于测定血浆样品中酒石酸美托洛尔的浓度.     

反相高效液相法测定盐酸曲马多血浆浓度及其药物动力学

采用反相高效液相法(PR-HPIC)对盐酸曲马多血浆药物浓度的测定方法及药物动力学进行了研究.实验应用Waters公司HPLC系统,WatersuBONDAPAK C18柱(4.6mm×150mm);测定采用内标峰高比定量,λ为216um.本方法最佳线性关系为r=0.9991,线性范围12.5～800ng/ml,最低检测浓度为6ng/ml,最低检测量0.12ng;方法平均回收率98.08%;浓度为800.00,200.00,50.00ng/ml的日内精密度分别为7.93,7.44,13.34,日间精密度分别为0.9,10.5,13.44.药物动力学参数分别为:T_（1/2） ka=0.51±0.23h,T_（1/2）β=5.92±2.57h,Tpeak=1.67± 0.61h,C_（max）=401.74±100.05ng/ml;AUCo_（→∞）=3242.92±1618.03(ng/ml)·h.     

高效液相色谱-串联质谱法测定牛奶中6种青霉素类药物的残留量

目的 建立一种高效液相串联质谱法,快速测定牛奶中6种青霉素类抗生素的残留鼍.方法 样品经乙腈沉淀蛋白,正己烷脱脂,氮吹浓缩,经高效液相色谱C18柱分离,选用含0.1%甲酸的水溶液和0.1%甲酸的乙腈溶液作流动相,在22 min内梯度洗脱将6种青霉素类抗生素得以分离.结果 方法 检出限为青霉素G 0.5ng/ml、青霉素V 1.0 ng/ml、苯唑西林1.0ng/ml、氯唑西林2.0ng/ml、阿莫西林2.0 ng/ml以及双氯西林1.0 ng/ml,在0.5～20 ng/ml线性范围内,相关系数r均大于0.990,平均回收率均大于80%.结论 该方法 前处理过程快速,结果 准确可靠,灵敏度高.     

HPLC-紫外法测定人血浆中芬太尼浓度

目的 :建立高效液相色谱法 -紫外检测器测定人血浆中芬太尼浓度的方法。方法 :本实验采用外标法 ,以Shim -PackCLC -ODS(6 0mm×150mm ,5μm )为固定相 ,含0 015mol/LNaH2PO4 的乙腈 -水溶液 (30∶70 ,v/v)为流动相 ,流速1 5ml/min ,紫外检测波长195nm。结果 :标准曲线在2 0～100ng/ml范围内线性关系良好 (r=0 999) ,最低检测浓度为1ng/ml,方法回收率为(91 70±4 70) % ,提取回收率为 (97 38±3 69) % ,日内变异RSD (6 50±2 79) % ,日间变异RSD (6 70±3 04) %。结论 :本方法简便 ,准确 ,检测浓度低 ,能够满足血浆中低浓度芬太尼的测定及临床药代动力学研究的要求。     

反相高效液相色谱法测定奥美拉唑镁肠溶片含量的研究

目的研究反相高效液相色谱法测定奥美拉唑镁肠溶片中有效成分的含量。方法采用Diamon-sil C18柱（4.6mm×250mm,5μm）;以甲醇-水-磷酸-三乙胺（70：30：0.12：0.3）为流动相,流速1.0ml/min,检测波长302nm,进量样20μl。结果奥美拉唑镁浓度在4～36μg/ml范围内,与峰面积呈良好的线性关系,r=1.0000（n=5）;最低检测浓度为0.5μg.ml-1;平均回收率为100.7%,RSD为0.27%（n=9）;奥美拉唑镁主峰与杂质峰能分离。结论采用反相高效液相色谱法测定奥美拉唑镁肠溶片的含量,方法简便,结果准确,专属性强,适用于奥美拉唑镁片剂的质量评价。     

LC/MS/MS方法研究克林霉素对人髓核组织的渗透性

目的 建立测定人血清和髓核中克林霉素的液相色谱-串联质谱联用法,并试用于临床受试者静脉滴注克林霉素磷酸酯后克林霉素在髓核的分布情况.方法 血清和髓核样品经乙腈沉淀蛋白后,以乙腈-1%甲酸(70:30,v/v)为流动相,林可霉素为内标,采用Hypersil BDS C18柱分离,通过液相色谱串联质谱仪,以选择反应监测(SRM)方式进行检测.结果 血清中克林霉素线性范围为500～20000 ng/ml,定量下限为500ng/ml;髓核中克林霉素线性范围为20～400ng/g,定量下限为20ng/g;9例临床受试者血清中克林霉素浓度为2674±1114 ng/ml,髓核中克林霉素浓度为51.2±39.5 ng/g.结论 静脉滴注克林霉素磷酸酯后能部分渗透到药理作用靶点髓核.     

高效液相色谱法测定血浆中平痛新的浓度

目的 :建立高效液相色谱法测定血浆中微量平痛新浓度的分析方法。方法 :采用HPLC法 ,色谱柱 :KromasilC18 柱 (Φ4 6mm×200mm ,5μm) ;流动相 :甲醇 -水 -三乙胺 (50∶50∶0 5) ;流速 :0 7ml/min ;检测波长 :215nm ;灵敏度 :0 04AUFS ;内标物 :奥美拉唑。结果 :血浆中平痛新浓度在10～600ng/ml范围内线性关系良好 ,相关系数r=0 9993 ;平均回收率为 (100 36±1 1) % ;平均日内和日间差异分别为4 7 %和3 8 % ;最低检测限可至1ng/ml。结论 :该法简便、稳定 ,可用于盐酸平痛新体内药代动力学与生物利用度研究。     

Buspirone, fexofenadine, and omeprazole: quantification of probe drugs and their metabolites in human plasma

Probe drugs are critical tools for the measurement of drug metabolism and transport activities in human subjects. Often several probe drugs are administered simultaneously in a "cocktail". This cocktail approach requires efficient analytical methods for the simultaneous quantitation of multiple analytes. We have developed and validated a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of three probe drugs and their metabolites in human plasma. The analytes include omeprazole and its metabolites omeprazole sulfone and 5'-hydroxyomeprazole; buspirone and its metabolite 1-[2-pyrimidyl]-piperazine (1PP); and fexofenadine. These analytes and the internal standard lansoprazole were extracted from plasma using protein precipitation with acetonitrile. Gradient reverse-phase chromatography was performed with 7.5mM ammonium bicarbonate and acetonitrile, and the analytes were quantified in positive ion electrospray mode with multiple reaction monitoring. The method was validated to quantify the concentration ranges of 1.0-1000ng/ml for omeprazole, omeprazole sulfone, 5'-hydroxyomeprazole, and fexofenadine; 0.1-100ng/ml for buspirone, and 1.0-100ng/ml for 1PP. These linear ranges span the plasma concentrations for all of the analytes from probe drug studies. The intra-day precision was between 2.1 and 16.1%, and the accuracy ranged from 86 to 115% for all analytes. Inter-day precision and accuracy ranged from 0.3 to 14% and from 90 to 110%, respectively. The lower limits of quantification were 0.1ng/ml for buspirone and 1ng/ml for all other analytes. This method provides a fast, sensitive, and selective analytical tool for quantification of the six analytes in plasma necessary to support the use of this probe drug cocktail in clinical studies.     

A pharmacokinetic interaction study between omeprazole and the H2-receptor antagonist ranitidine

The effect of ranitidine pretreatment on the pharmacokinetics of omeprazole was investigated in 14 male human volunteers. Omeprazole (40 mg, gastroresistant pellets) was administered to the volunteers in a two-treatment study design, either alone or after 5 days pretreatment with b.i.d. doses of 150 mg ranitidine. Plasma concentrations of omeprazole were determined over a 24-hour period following drug administration, by a validated RP-HPLC method. Pharmacokinetic parameters were calculated with compartmental and non-compartmental analysis, using the computer program Kinetica (Inna Phase). In the two periods of treatments, the mean peak plasma concentrations Cmax were 730.8 ng/ml for omeprazole alone and 802.1 ng/ml for omeprazole co-administered with ranitidine (not significant). The time taken to reach the peak, Tmax, was 1.29 h and 1.42 h, respectively (not significant). The areas under the curve (AUC0-10) were 1,453.3 ng.h/ml and 1,736.8 ng.h/ml for the two periods of treatment; thus a greater AUC was obtained after pretreatment with multiple doses of ranitidine. Our data show that the pharmacokinetics of omeprazole might be inhibited by pretreatment with ranitidine; however, the clinical relevance of this interaction still has to be confirmed.     

Validation of an automated liquid chromatographic method for omeprazole in human plasma using on-line solid-phase extraction

An automated system using on-line solid-phase extraction and HPLC with UV detection has been validated in order to determine omeprazole in human plasma. The extraction was carried out using C18 cartridges. After washing, omeprazole was eluted from the cartridge with mobile phase onto an Inertsil ODS-2 column. The developed method was selective and linear for drug concentrations ranging between 5 and 500 ng ml(-1). The recovery of omeprazole ranged from 88.1 to 101.5%, and the limit of quantitation (LOQ) was 5 ng ml(-1). The intraday accuracy ranged from 93.1 to 106.2% and the interday accuracy varied from 95.4 to 105.1%. For the LOQ, good values of precision (8.7 and 17.5% for intraday and interday, respectively) were also obtained. This automated system has been applied to determine omeprazole in human plasma samples from bioequivalence studies.     

Advanced method for determination of omeprazole in plasma by HPLC

An advanced and sensitive high-performance liquid chromatographic (HPLC) method for determination of omeprazole in human plasma has been developed. After omeprazole was extracted from plasma with diethylether, the organic phase was transferred to another tube and trapped back with 0.1 N NaOH solution. The alkaline aqueous layer was injected into a reversed-phase C8 column. Lansoprazole was used as an internal standard. The mobile phase consisted of 30% of acetonitrile and 70% of 0.2 M KH2P04, pH 7.0. Recoveries of the analytes and internal standard were >75.48%. The coefficients of variation of intra- and inter-day assay were <5.78 and 4.59% for plasma samples. The detection limit in plasma was 2 ng/ml. The clinical applicability of this assay method was evaluated by determining plasma concentration-time courses of the respective analytes in 24 healthy volunteers after oral administration 40 mg of omeprazole. The present assay is considered to be simple, accurate, economical and suitable for the study of the kinetic disposition of omeprazole in the body.     

Improved high performance liquid chromatographic analysis of omeprazole in human plasma

A simple high-performance liquid chromatographic method was developed for the determination of omeprazole in human plasma. Omeprazole and the internal standard, chloramphenicol, were extracted from alkalinized plasma samples using dichloromethane. The mobile phase was 0.05 M Na2HPO4-ACN (65:35, v/v) adjusted to pH 6.5. Analysis was run at a flow rate of 1.0 ml/min at a detection wavelength of 302 nm. The method was specific and sensitive with a detection limit of 2.5 ng/ml at a signal-to-noise ratio of 4:1. The limit of quantification was set at 5 ng/ml. The calibration curve was linear over a concentration range of 5-1280 ng/ml. Mean recovery value of the extraction procedure was about 96%, while the within and between day coefficient of variation and percent error values of the assay method were all less than 14%.     

Stereoselective interaction of omeprazole with warfarin in healthy men

The effect of concomitant treatment with omeprazole (20 mg/day) on the plasma concentration and anticoagulation effect of warfarin was studied in 21 young healthy men. An initial three weeks' treatment with warfarin alone was administered to determine the doses required for the subjects' vitamin K-dependent coagulation factors to fall within 10-20% of the normal range, as determined by the Trombotest. Omeprazole and placebo were then administered concomitantly with warfarin for 2 weeks each in a double-blind, randomized, crossover fashion. Plasma concentrations of (R)- and (S)-warfarin, and Trombotest values were measured daily on weekdays throughout the crossover period. Omeprazole had no apparent effect on the mean (S)-warfarin plasma concentration (379 ng/ml with, versus 387 ng/ml without, omeprazole), but caused a slight (12%) although statistically significant increase in the mean (R)-warfarin concentration from 490 to 548 ng/ml (95% confidence interval for difference of means: 28-88). The Trombotest values exhibited large inter- and intrasubject variability during both omeprazole and placebo treatment; however, there was a small, although statistically significant decrease in the mean value from 21.1% without to 18.7% with omeprazole treatment (95% CI for difference of means: -4.6- -0.1). Those subjects with Trombotest values nearest the therapeutic range (5-15%) exhibited less change during omeprazole treatment, and no changes occurred that required a change in warfarin dosing. The interaction of omeprazole with warfarin was attributed to a stereoselective inhibition of the hepatic metabolism of the less potent (R)-warfarin enantiomer. The small effect of omeprazole on the anticoagulation activity of warfarin is not likely to be of clinical importance.     

Different inhibitory effect of fluvoxamine on omeprazole metabolism between CYP2C19 genotypes

AIMS: Omeprazole is mainly metabolized by the polymorphic cytochrome P450 (CYP) 2C19. The inhibitory effect of fluvoxamine, an inhibitor of CYP2C19 as well as CYP1A2, on the metabolism of omeprazole was compared between different genotypes for CYP2C19. METHODS: Eighteen volunteers, of whom six were homozygous extensive metabolizers (EMs), six were heterozygous EMs and six were poor metabolizers (PMs) for CYP2C19, participated in the study. A randomized double-blind, placebo-controlled crossover study was performed. All subjects received two six-day courses of either daily 50 mg fluvoxamine or placebo in a randomized fashion with a single oral 40 mg dose of omeprazole on day six in both cases. Plasma concentrations of omeprazole and its metabolites, 5-hydroxyomeprazole, omeprazole sulphone, and fluvoxamine were monitored up to 8 h after the dosing. RESULTS: During placebo administration, geometric means of peak concentration (C(max)), under the plasma concentration-time curve from 0 to 8 h (AUC(0,8 h)) and elimination half-life (t(1/2)) of omeprazole were 900 ng ml(-1), 1481 ng ml(-1) h, and 0.6 h in homozygous EMs, 1648 ng ml(-1), 4225 ng ml(-1) h, and 1.1 h in heterozygous EMs, and 2991 ng ml(-1), 11537 ng ml(-1) h, and 2.8 h in PMs, respectively. Fluvoxamine treatment increased C(max) of omeprazole by 3.7-fold (95%CI, 2.4, 5.0-fold, P < 0.01) and 2.0-fold (1.4, 2.6-fold, P < 0.01), AUC(0,8 h) by 6.0-fold (3.3, 8.7-fold, P < 0.001) and 2.4-fold (1.7, 3.2-fold, P < 0.01), AUC(0, infinity ) by 6.2-fold (3.0, 9.3-fold, P < 0.01) and 2.5-fold (1.6, 3.4-fold, P < 0.001) and prolonged t((1/2)) by 2.6-fold (1.9, 3.4-fold, P < 0.001) and 1.4-fold (1.02, 1.7-fold, P < 0.05), respectively. However, no pharmacokinetic parameters were changed in PMs. The AUC(0,8 h) ratios of 5-hydroxyomeprazole to omeprazole were decreased with fluvoxamine in homozygous EMs (P < 0.05) and heterozygous EMs (P < 0.01). CONCLUSIONS: Even a low dose of fluvoxamine increased omeprazole exposure in EMs, but did not increase omeprazole exposure in PMs after a single oral dose of omeprazole. These findings confirm a potent inhibitory effect of fluvoxamine on CYP2C19 activity. The bioavailability of omeprazole might, to some extent, be increased through inhibition of P-glycoprotein during fluvoxamine treatment.     

右旋兰索拉唑双相释放胶囊在Beagle犬体内的药动学研究

建立了LC-MS/MS法测定犬血浆中的右旋兰索拉唑,并研究了右旋兰索拉唑控释胶囊(商品名:Dexilant)在Beagle犬体内的药动学.采用C18柱,以甲醇-水(含10 mmol/L甲酸铵,70:30)为流动相,奥美拉唑为内标.右旋兰索拉唑在5～2 000 ng/ml浓度范围内线性关系良好,提取回收率105.7％～123.1％,批内、批间RSD均小于10％.Beagle犬口服给药后,呈明显血药双峰现象,药动学参数t1/2为(0.6±0.1)h,AUC0-∞为(2 019±176) ng·ml-1h,cmax为(810.9±194.0) ng/ml.     

HPLC-MS／MS法测定大鼠血浆中兰索拉唑及其代谢产物的浓度

目的：建立大鼠血浆中兰索拉唑及其代谢产物5-羟基兰索拉唑、兰索拉唑砜的HPLC-MS／MS测定方法。方法：色谱条件：色谱柱：Diamonsil C18柱（150mm×2．1mm,5um）;流动相：乙腈-水（合0．01％甲酸及2mmol·L-1的醋酸铵（43：57,V／V）;流速：0．3ml·min-1;柱温：40℃;进样量10ul。质谱条件：电喷雾离子源（ESI）,以多反应监测离子方式测定兰索拉唑及其代谢产物,选择性监测质荷比（m／z）为368．0／163．9（兰索拉唑）,384．1／179．9（5-羟基兰索拉唑）,383．9／115．9（兰索拉唑砜）,326．0／280．1（内标奥美拉唑）。样品用乙腈沉淀蛋白处理。结果：兰索拉唑、5-羟基兰索拉唑、兰索拉唑砜的线性范围分别为11．40～4560．00,1．26～504．00,1．24～496．00ng·ml-1;定量下限分别为11．40,1．26,1．24ng·ml-1;批内、批间精密度RSD均〈15％。结论：该方法灵敏、准确、快速、专属性好,适用于兰索拉唑及其代谢产物在大鼠体内的药代动力学研究。     

Influence of fluconazole on the pharmacokinetics of omeprazole in healthy volunteers

Influence of fluconazole on the pharmacokinetics of omeprazole was evaluated by single oral administration of omeprazole capsule 20 mg (control group), or single oral administration of fluconazole capsule, 100 mg, and omeprazole, 20 mg, after 4 days of daily oral administration of fluconazole, 100 mg (treated group), to 18 healthy male volunteers. Omeprazole is extensively metabolized in the liver through 5-hydroxylation and sulfoxidation reactions catalyzed predominantly by CYP2C19 and CYP3A4, respectively. Fluconazole is a potent competitive inhibitor of CYP2C19 and a weak inhibitor of CYP3A4. In treated group, the area under the plasma concentration-time curve of omeprazole from time zero to time infinity (AUC) was significantly greater (3090 vs 491 ng h/ml), terminal half-life of omeprazole was significantly longer (2.59 vs 0.85 h), and peak plasma concentration of omeprazole (C(max)) was significantly higher (746 vs 311 ng/ml) than that in control group. The greater AUC and higher C(max) in treated group could be due to inhibition of omeprazole metabolism by fluconazole.