高脂饮食对双嘧达莫在中国健康人体内药动学的影响

目的 观察中国健康受试者空腹和高脂高热量饮食情况下口服双嘧达莫片的药动学特征。方法 75名健康受试者分别在空腹或高脂饮食条件下单剂量口服双嘧达莫片25 mg,分别在不同时间点采集静脉血样。采用LC-MS/MS测定人血浆中双嘧达莫的浓度,用PhoenixWinNonlin 8.0软件按非房室模型计算药动学参数。结果 空腹和高脂饮食后双嘧达莫片的主要药动学参数如下：C_max分别为(594.69±172.14),(333.64±167.18) ng·mL^-1,餐后较空腹C_max降低了43.9%(P<0.01);t_1/2分别为(9.87±4.21),(10.57±3.75) h;AUC_0-t分别为(1 733.22±715.49),(1 268.61±571.07) ng·mL^-1·h,AUC_0-∞分别为(1 801.69±707.61),(1 353.64±602.29) ng·mL^-1·h,餐后较空腹AUC_0-t及AUC_0-∞分别降低26.8%,24.9%(P<0.01);T_max中位数(范围)分别为0.75[0.50,5.00] h和1.50[0.49,4.52] h,餐后服药的T_max明显延迟(P<0.01)。结论 高脂饮食后服药较空腹条件下服药,C_max、AUC_0-t及AUC_0-∞均明显降低,T_max明显延迟,说明食物对双嘧达莫片的吸收速度、吸收程度均有显著影响。     

美洛昔康咀嚼片的生物等效性研究

目的 研究美洛昔康咀嚼片在比格犬体内的药动学和生物等效性。方法 12只健康成年比格犬随机分为2组,采用双周期交叉实验设计,分别口服测试片剂和参比片剂2 mg,用RP-HPLC方法测定血浆中美洛昔康的浓度,应用3P97软件计算药动学参数,并进行两种制剂的生物等效性评价。结果 测试片剂和参比片剂的AUC_{0~96 h}分别为（2.85±0.64）和（2.79±0.48）μg/mL·h,T_max分别为（4.33±0.65）和（4.16±0.71）h,C_max分别为（0.091±0.017）和（0.086±0.021）μg/mL,t_1/2分别为（26.08±3.64）和（26.94±4.21）h,两者的lnAUC和lnC_max经双单侧t检验证明差异无统计意义。结论 测试片剂与国外上市的参比片剂具有生物等效性,其平均相对生物利用度为（98.0±9.76）%。     

盐酸二甲双胍缓释片的人体生物等效性研究

目的 评价中国健康受试者空腹和餐后状态下单次口服盐酸二甲双胍缓释片的生物等效性。方法 采用单剂量、随机、开放、两制剂、两周期、交叉对照的试验设计,健康受试者每周期在空腹或餐后状态下口服盐酸二甲双胍缓释片受试制剂和参比制剂500 mg。采用经验证的液相色谱-串联质谱（LC-MS/MS）法测定二甲双胍的血浆浓度,使用Phoenix WinNonlin 8.0计算药动学参数并用SAS9.4软件进行生物等效性评价。结果 空腹状态下,受试制剂和参比制剂中二甲双胍C_max分别为（733.00±178.25）、（665.80±146.58） ng·mL^-1,AUC_0～t分别为（4 848.60±1 204.80）、（4 743.00±1 104.34） h·ng·mL^-1,AUC_{0 ～ ∞}分别为（4 940.70±1 219.48）、（4 832.58±1 093.55） h·ng·mL^-1。餐后状态下,受试制剂和参比制剂中二甲双胍C_max分别为（519.10±92.55）、（475.50±65.88） ng·mL^-1,AUC_0～t分别为（5 989.20±1 112.01）、（5 946.50±1 094.81） h·ng·mL^-1,AUC_{0 ～ ∞}分别为（6 052.20±1 118.35）、（6 049.80±1 062.28） h·ng·mL^-1。受试制剂和参比制剂二甲双胍C_max、AUC_0～t和AUC_0～∞几何均值比的90%置信区间均在80.00%～125.00%的生物等效性范围内。结论 盐酸二甲双胍缓释片受试制剂和参比制剂在空腹和餐后状态下均具有生物等效性。     

国产重组人促红素注射液与进口制剂在大鼠体内的药动学对比研究

目的 对国产重组人促红素注射液（济脉欣）与进口同类型制剂Eprex^®在大鼠体内的药动学进行对比研究,为实现临床替代提供依据。方法 采用¹²⁵I标记示踪方法测定药物浓度,采用DAS2.0进行药动学参数的计算,在大鼠体内分别进行单次sc 2 000 U/kg济脉欣和Eprex^®的血浆药物动力学对比研究、药物组织分布对比研究和尿、粪、胆汁排泄对比研究。结果 大鼠sc相同剂量（2 000 U/kg）的济脉欣和Eprex^®后,RA法所得血浆动力学参数：t_1/2分别为（15.8±1.67）和（15.6±3.15）h;C_max分别为（2 527±471）和（2 470±598）mU/mL;t_max分别为（10.3±1.51）和（9.00±2.45）h;AUC_0-t分别为（64 196±12 544）和（59 630±9 391）mU/mL·h,TCA-RA法所得血浆动力学参数：t_1/2分别为（15.9±4.19）和（16.2±2.45）h;C_max分别为（2 201±584）和（1 907±517）mU/mL;t_max分别为（10.0±1.27）和（9.00±2.45）h;AUC_0-t分别为（53 709±11 992）和（48 519±8 623）mU/mL·h。用RA和TCA-RA法测定济脉欣和Eprex^®给药后2、8、24、36 h各主要脏器及组织药物浓度,显示大部分组织在给药后8 h药物含量最大,然后逐渐降低,各主要脏器及组织药物变化趋势与血浆药物消除一致,没有发现蓄积现象。大鼠sc给药济脉欣和Eprex^®后,在120 h内从尿中分别可回收到给药总量的75.7%和76.2%,在粪中可回收到给药量的14.7%和14.9%。48 h内胆汁排泄量为11.4%和10.3%。结论 国产重组人促红素注射液济脉欣与国外上市制剂Eprex^®大鼠sc给药后,主要药动学参数t_1/2、t_max、C_max和AUC_0-t基本一致,经统计检验无差异;两种制剂在各组织脏器内的暴露以及尿、粪、胆汁排泄对比也无差异。     

甲磺酸多沙唑嗪缓释片Beagle犬体内药动学和生物等效性研究

目的 研究甲磺酸多沙唑嗪（Dox）缓释片在Beagle犬体内的药动学，评价其生物等效性。方法 8条健康Beagle犬，采用双周期、双交叉、单剂量分别ig Dox缓释片受试制剂或参比制剂4 mg；建立血浆中Dox液相色谱-质谱联用（LC-MS/MS）检测方法，进行方法精密度、准确度、回收率、基质效应、稳定性方法学验证；测定给药前（0 h）及给药后2、3、4、5、6、8、10、12、14、16、24、36、48、72 h血浆中Dox经时血药浓度，运用DAS3.2.8计算其药动学参数，并评价其生物等效性。结果 LC-MS/MS方法学经验证符合检测要求。主要药动学参数如下：受试制剂与参比制剂的C_max分别为（29.998 ±3.725）、（31.207 ±5.586） ng/mL，T_max分别为（11.5 ±2.33）、（11.25 ±1.035） h，AUC_0-t分别为（528.549 ±84.526）、（539.852±94.232） ng· h/mL；受试制剂AUC_0-t、AUC_0-∞和C_max的90%置信区间分别为参比制剂相应参数的84.6%~113.9%、88.6%~107.5%和90.2%~104%，均在80%~125%范围内。结论 Dox缓释片受试制剂与参比制剂生物等效。     

依托考昔片在中国健康受试者的药动学及安全性研究

目的 研究中国健康受试者空腹、餐后单次口服依托考昔片的药动学及安全性。方法 将68例健康受试者随机分为空腹组和餐后组，采用双周期交叉试验设计进行给药，LC-MS/MS测定人血浆中依托考昔浓度，用WinNonLin软件计算药动学参数，比较国产依托考昔片和原研参比制剂药动学差异以及不同性别和进食对托考昔片药动学的影响。以受试者生命体征及体格检查、实验室检查值以及心电图变化为指标进行依托考昔片安全性评价。结果 空腹组受试制剂和参比制剂的药动学参数T_max为1.25，1.25 h，C_max为（2 767.50±421.89），（2 707.81±674.90） ng·mL^-1，AUC_0-∞为（52 967.87±13 843.25），（53 479.56±16 066.32） h·ng·mL^-1；餐后组受试制剂和参比制剂的药动学参数T_max为2.50，1.75 h，C_max为（2 000.61±314.89），（2 209.06±429.05） ng·mL^-1，AUC_0-∞为（51 450.80±17 241.02），（49 287.23±16 192.87） h·ng·mL^-1；餐后组受试制剂和参比制剂T_max差异具有统计学意义（P<0.05），但不具有临床意义。受试者空腹、餐后口服依托考昔片后，T_max、C_max差异具有统计学意义（P<0.01），但AUC_0-∞差异无统计学意义；不同性别受试者空腹口服依托考昔片后，主要药动学参数T_max、C_max、AUC_0-∞均无统计学意义，但女性受试者餐后口服依托考昔片后t_1/2、AUC_0-∞较男性受试者高（P<0.05）。空腹和餐后给药后不良事件涉及多系统，均为轻度，无严重不良反应。结论 国产依托考昔片和原研参比制剂具有生物等效性；进食影响依托考昔片的吸收速度，但不影响其吸收程度；空腹给药后依托考昔片的药动学参数无性别差异，但餐后给药后t_1/2、AUC_0-∞存在性别差异。依托考昔片在中国健康受试者中具有良好的安全性和耐受性。     

莫西沙星在肺炎大鼠与正常大鼠的血浆及肺组织中药动学比较

目的 莫西沙星（MXF）口服给药在被肺炎链球菌（S.p）感染肺炎大鼠与正常大鼠的血浆及肺组织中药动学比较研究。方法 建立肺炎链球菌肺炎大鼠和正常大鼠模型,莫西沙星42 mg/kg灌胃给药,采用微透析技术对肺炎大鼠及正常大鼠的血液及肺组织取样,用高效液相色谱法测定莫西沙星在各样本中的游离药物浓度,计算药动学参数,进行肺炎大鼠和正常大鼠口服莫西沙星的药动学比较。结果 莫西沙星在正常大鼠及肺炎大鼠血液中的t_1/2分别为（5.27±4.38）h、（2.15±0.07）h（P>0.05）,C_max分别为（4.94±0.98）μg/ml、（4.83±0.05）μg/ml（P>0.05）,C_{last_obs}/C_max分别为0.02±0.03、0.27±0.04（P<0.05）,AUC_0-t分别为（22.33±2.02）μg/ml·h、（12.88±1.19）μg /ml·h（P<0.05）,CL/F 分别为（1.79±0.11）(mg/kg)/(μg/ml)·h、（2.49±0.26）(mg/kg)/(μg/ml)·h（P<0.05）;在正常大鼠及肺炎大鼠肺组织中的C_max分别为（1.42±0.05）μg/ml、（4.84±0.02）μg /ml（P<0.05）,t_1/2分别为（1.9±0.63）h、（3.39±0.79）h（P>0.05）,AUMC分别为（11.93±5.14）μg/ml·h²、（107.01±25.39）μg/ml·h²（P<0.05）,AUC_0-t分别为（3.06±1.0）7μg/ml·h、（13.16±0.53）μg /ml·h（P<0.01）。结论 ①在400mg/d剂量条件下,莫西沙星灌胃给药后,血液及肺组织内的游离药物浓度较高,远超过最低抑菌浓度（MIC）和防耐药突变浓度（MPC）,可以有效清除肺炎链球菌。②肺炎链球菌感染大鼠肺组织中莫西沙星游离浓度始终高于正常大鼠,C_max约为正常大鼠的3.4倍,莫西沙星在肺炎大鼠的肺组织穿透率显著高于正常大鼠。     

非诺贝特双层渗透泵片在Beagle犬体内的药动学研究

目的 研究非诺贝特双层渗透泵片在犬体内的药动学特征,并评价受试制剂和参比制剂的生物等效性。方法 采用LC-MS测定比格犬体内的血药浓度,采用DAS 2.1.1软件计算药动学参数。结果 受试制剂和参比制剂血浆中非诺贝特酸的C_max分别为（1 100.0±771.2）、（924.3±564.0）ng/mL,t_max分别为（6.7±8.5)、（2.5±0.5）h,AUC0-t分别为（17 841.1±12 220.7）、（17 615.5±12 870.2）ng·h/mL;t_1/2分别为（17.7±8.2）、（16.4±3.3）h,MRT_0-t分别为（24.7±4.0）、（24.5±5.2）h,受试制剂中非诺贝特酸的平均相对生物利用度为（104.7±12.4）%。结论 受试制剂非诺贝特渗透泵片和参比制剂非诺贝特缓释胶囊具有生物等效性。     

阿哌沙班在大鼠体内药动学/药效学研究

目的 考察阿哌沙班大鼠体内药动学并评价其与药效学的相关性。方法 采用超高效液相色谱-串联质谱（UPLC-MS/MS）测定不同时间阿哌沙班血药浓度并绘制血药浓度-时间曲线,同时测定各时间点凝血酶原时间（PT）延长倍数并绘制药效-时间曲线,对药动及药效进行相关性分析。结果 阿哌沙班以2 mg/kg剂量iv给予大鼠,血药浓度时间曲线下面积（AUC_0-∞）、半衰期（t_1/2z）分别为（4 016.07±1 160.46）μg·h/L、（2.95±1.59）h;以10 mg/kg剂量ig给药,AUC_0-∞、t_1/2z、峰浓度（C_max）、达峰时间（t_max）、生物利用度（F）分别为（17 973.48±3 145.30）μg·h/L、（1.52±0.36）h、（4 949.12±615.38）μg/L、（1.00±0.71）h、89.5%。阿哌沙班以10 mg/kg剂量ig给药后0.5~2.0 h可显著延长PT,以各时间点PT延长倍数对血药浓度作图呈良好的线性关系。结论 阿哌沙班大鼠ig给药F高,吸收迅速,延长PT的效应与血药浓度呈现良好的相关性。     

国产与进口头孢地尼颗粒在健康人体的生物等效性研究

目的 建立测定人血浆中头孢地尼的液相色谱-串联质谱(LC-MS/MS)方法,并用于评价头孢地尼颗粒在人体的生物等效性。方法 24名健康男性受试者随机交叉单剂量口服头孢地尼颗粒受试制剂和参比制剂100 mg,采用LC-MS/MS法测定人血浆样本中头孢地尼,WinNonlin 6.3软件计算其药动学参数,并评价两种制剂的生物等效性。结果 血浆中头孢地尼的线性范围为10.0~2000 ng/mL(r=0.9997),定量下限为10.0 ng/mL;批内、批间精密度(RSD)均小于6.0%,准确度(RE)在±4.0%以内;随着放置时间的延长,血浆中头孢地尼在室温条件下降解程度增加。受试制剂和参比制剂的AUC_0-t分别为(6238.22±1993.74)、(6331.35±1850.42)ng·h/mL,AUC_0-∞分别为(6343.68±2070.73)、(6429.76±1901.33)ng·h/mL,C_max分别为(1290±391)、(1330±384)ng/mL,t_max分别为2.50(2.00~4.50)、2.50(2.00~3.50)h,t_1/2分别为(1.61±0.17)、(1.61±0.17)h。AUC_0-t、AUC_0-∞和C_max的几何平均数比值(GMR)分别为97.88%、97.95%、96.75%,其90%置信区间分别为91.75%~104.42%、91.76%~104.56%、90.43%~103.52%。结论 该方法快速、灵敏、准确、专属性强、重现性好,适用于人血浆头孢地尼的测定。头孢地尼颗粒受试制剂和参比制剂具有生物等效性。     

左乙拉西坦缓释片的制备及其Beagle犬体内药动学研究

目的 制备左乙拉西坦缓释片,进行体外释放特性以及Beagle犬体内药动学研究。方法 按照筛选处方制备左乙拉西坦缓释片,以市售左乙拉西坦缓释片（Keppra-XR）为参比制剂,采用相似因子（f₂）法进行体外释放行为相似度评价;并将自制左乙拉西坦缓释片与市售普通片进行Beagle犬体内药动学参数比较。结果 自制左乙拉西坦缓释片与市售左乙拉西坦缓释片体外释放行为相似。市售左乙拉西坦普通片和自制左乙拉西坦缓释片的药动学参数T_max分别为（1.75±0.50）和（5.50±1.00）h,C_max分别为（30.33±2.00）和（17.29±3.56）mg·L^-1,AUC_0-t分别为（186.88±8.83）和（202.50±34.20）mg·L^-1·h。结论 自制的左乙拉西坦缓释片具有缓释效果。     

Effect of Fascioliasis on the pharmacokinetic parameters of triclabendazole in human subjects

Objectives To study the clinical efficacy of Triclabendazole (TCBZ) on Egyptian patients infected with Fasciola and understand the effect of Fascioliasis on the pharmacokinetics of TCBZ. Methods The pharmacokinetics of TCBZ administered as a single oral dose (10 mg/kg) was investigated in both infected and parasite––free Egyptian subjects. After oral administration, TCBZ is metabolized to a sulphone and sulfoxide derivatives. The latter is responsible for the fasciolicidal activity of TCBZ, and it could be used as a marker of drug bioavailability. Blood samples were collected following the oral administration, and TCBZ sulfoxide plasma concentrations were determined by a sensitive and specific HPLC method. Results Pharmacokinetic parameters (C _max, AUC_0–48, t _1/2 and t _max) for TCBZ sulfoxide were calculated. In patients; the mean C _max was 9.11 ± 1.3 μg/ml, the mean AUC _(0–48) was 91 ± 10.5 μg h ml⁻¹, the mean t _1/2 was 7.4 ± 0.6 h, and the t _max was 3.0 ± 0.4 h. In normal subjects, the mean C _max was 8.48 ± 0.92 μg/ml, the mean AUC_(0–48) was 85 ± 6.55 μg h ml⁻¹, the mean t _1/2 was 6.2 ± 0.357 h, and the t _max was 3 ± 0.4 h. No significant difference could be detected in the patients as compared to normal subjects, which would suggest that Fascioliasis does not affect any of the studied parameters. No eggs in faeces could be detected following TCBZ treatment. Also, most of the clinical investigations showed significant decline back to the normal ranges post-treatment which indicates complete curing and high TCBZ efficacy. Conclusion Fasioliasis as an infective condition widely spread in Egypt has no significant effect on the pharmacokinetic parameters of the orally administered TCBZ and at the same time it is very effective against the parasite which strongly and safely suggests the use of this medication for the treatment of this infection.     

HPLC determination and pharmacokinetics of the new original domestic drug dibufelon®

A simple, specific, sensitive, and precise high-performance liquid chromatography (HPLC) assay with UV detection has been developed for quantitative determination of fenozan acid in human blood plasma. Using this method, the pharmacokinetics of the new domestic preparation dibufelon (OOO Consortium-PIK, Russia) were investigated after a single peroral administration of an 800-mg dose in 12 healthy volunteers. It is established that the drug is rapidly absorbed from the GI tract into the systemic blood flow [C _max ,178 ± 29 ng/mL; T _max, 3.9 ± 0.5 h; AUC _0–∞, 1434 ± 269 (ng ∙ h)/mL; C _max/AUC _0–∞, 0.135 ± 0.011 L/h], rather well retained in humans (MRT, 8.6 ± 0.8 h; T ₁/₂, 5.3 ± 0.8 h), and, despite a rapid total clearance (Cl _t ,824 ± 167 L/h), penetrates well into organs and tissues (V _Z , 5590 ± 1204 L).     

Effect of nebicapone on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects

Objective  Nebicapone is a new catechol-O-methyltransferase inhibitor. In vitro, nebicapone has showed an inhibitory effect upon CYP2C9, which is responsible for the metabolism of S-warfarin. The objective of this study was to investigate the effect of nebicapone on warfarin pharmacokinetics and pharmacodynamics in healthy subjects. Methods  Single-centre, open-label, randomised, two-period crossover study in 16 healthy volunteers. In one period, subjects received nebicapone 200 mg thrice daily for 9 days and a racemic warfarin 25-mg single dose concomitantly with the nebicapone morning dose on day 4 (test). In the other period, subjects received a racemic warfarin 25-mg single dose alone (reference). The treatment periods were separated by a washout of 14 days. Results  For R-warfarin, mean ± SD C_max was 1,619 ± 284 ng/mL for test and 1,649 ± 357 ng/mL for reference, while AUC_0-t was 92,796 ± 18,976 ng·h/mL (test) and 73,597 ± 11,363 ng·h/mL (reference). The R-warfarin test-to-reference geometric mean ratio (GMR) and 90% confidence interval (90%CI) were 0.973 (0.878–1.077) for C_max and 1.247 (1.170–1.327) for AUC_0-t . For S-warfarin, mean ± SD C_max was 1,644 ± 331 ng/mL for test and 1,739 ± 392 ng/mL for reference, while AUC_0-t was 66,627 ± 41,199 ng·h/mL (test) and 70,178 ± 42,560 ng·h/mL (reference). The S-warfarin test-to-reference GMR and 90%CI were 0.932 (0.845–1.028) for C_max and 0.914 (0.875–0.954) for AUC_0-t . No differences were found for the pharmacodynamic parameter (INR). Conclusion  Nebicapone showed no significant effect on S-warfarin pharmacokinetics or on the coagulation endpoint (INR). A mild inhibition of the R-warfarin metabolism was found but is unlikely to be of clinical relevance.     

栀子-闹羊花配伍对大鼠血浆中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的药动学影响

目的考察栀子与闹羊花配伍对闹羊花中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ药动学的影响。方法建立LC-MS/MS测定大鼠血浆中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的分析方法,并用此方法测定大鼠口服给予闹羊花与栀子配伍液及闹羊花单煎液后大鼠体内的闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的血药浓度,计算其药动学参数并统计分析。结果闹羊花毒素Ⅱ在1～200 ng·mL^–1、闹羊花毒素Ⅲ在1～100 ng·mL^–1内线性关系良好(r>0.999),质控样本精密度均<12%,准确度RSD<20%。栀子配伍闹羊花给药和单独给药后体内闹羊花毒素Ⅱ的AUC_0–t分别为(260.44±51.67)和(213.39±59.03) h·ng·mL^–1,闹羊花毒素Ⅲ的AUC_0–t分别为(60.97±22.78)和(22.38±5.55)h·ng·mL^–1。与闹羊花单煎给药相比,栀子与闹羊花配伍给药后闹羊花毒素Ⅱ的T_1/2和MRT₍(0–t))显著升高,闹羊...     

单剂量口服茶碱缓释胶囊的人体生物等效性评价

目的选择12名男性健康志愿者,进行单剂量口服茶碱缓释胶囊的人体生物等效性评价。方法采用反相高效液相色谱法,以紫外273nm为检测波长,测定了单剂量口服200mg国产茶碱缓释胶囊受试药品在健康人体内的茶碱浓度,并与进口茶碱缓释胶囊参比药品进行对照。结果茶碱缓释胶囊的体内动态过程呈一级吸收的一房室开放模型,国产受试药品和进口参比药品的Cmax分别为(5.12±0.74)mg/L和(5.14±0.63)mg/L,tmax分别为(5.4±1.0)h和(5.3±1.1)h,MRT分别为(17.79±1.48)h和(17.61±1.78)h,t1/2分别为(10.55±0.75)h和(10.59±1.10)h,AUC0-36分别为(85.33±10.56)mg*h/L和(86.26±8.80)mg*h/L。结论以体内茶碱AUC0-36数值表征的国产茶碱缓释胶囊的相对生物利用度为(98.9±6.4)%;选择Cmax、AUC0-36和AUC0-∞进行三因素方差分析与双单侧t检验,结果表明国产茶碱缓释胶囊和进口茶碱缓释胶囊两种制剂具有生物等效性。     

Influence of UGT1A8 and UGT2B7 genetic polymorphisms on mycophenolic acid pharmacokinetics in Japanese renal transplant recipients

Objective UGT1A8 and UGT2B7 are important uridine diphosphate-glucuronosyltransferase isoforms for the glucuronidation of mycophenolic acid (MPA). The aim of this investigation was to elucidate MPA pharmacokinetics in UGT1A8 and UGT2B7 genotypes in Japanese renal transplant recipients. Methods Seventy-two recipients received repeated doses of mycophenolate mofetil and tacrolimus. On day 28 after renal transplantation, plasma MPA concentrations were measured for the next 24 h using high-performance liquid chromatography. UGT1A8*2 (A¹⁷³G) and UGT2B7*2 (Y²⁶⁸) were detected using a PCR-RFLP-based procedure. Results There were no significant differences in daytime and nighttime pharmacokinetics of MPA between UGT1A8 or UGT2B7 genotypes. The mean daytime dose-adjusted AUC_0–12 of MPA in UGT1A8*1/*1, *1/*2 and *2/*2 were 2.47, 2.33 and 2.57 ng·h/ml/mg/kg (P = 0.7711), and the mean nighttime AUC_0–12 were 2.15, 2.00 and 2.08 ng·h/ml/mg/kg (P = 0.4656). The mean daytime and nighttime dose-adjusted AUC_0–12 of MPA in UGT2B7*1/*1, *1/*2 and *2/*2 were 2.61, 2.24 and 2.03 ng·h/ml/mg/kg and 2.18, 1.94, and 1.45 ng·h/ml/mg/kg, respectively (P = 0.3475 and 0.2575). The mean nighttime C_max, t_max, and AUC_6–12/AUC_0–12 ratio (enterohepatic circulation and recirculation ratio) of MPA in all UGT1A8 and UGT2B7 genotypes were lower, longer, and higher, respectively, than the daytime values. Conclusions Both UGT1A8 and UGT2B7 allelic variants seem not to affect Japanese interindividual variability for plasma MPA concentration. Regardless of UGT1A8 and UGT2B7 genetic polymorphisms, the absorption of MPA through enterohepatic recirculation is higher at night.     

Pharmacokinetic profile of sildenafil citrate in healthy Middle Eastern Males: Comparison with other ethnicities

Aim1) To investigate the pharmacokinetic profile of sildenafil citrate in Middle Eastern males and, 2) To highlight the impact of ethnicity on its pharmacokinetics parameters through comparing Middle Eastern data to the data estimated from different ethnic groups.MethodThe study was conducted on 24 Middle Eastern healthy male volunteers. Pharmacokinetic data including C_max, T_max, t_1/2, AUC_0-t, AUC_0-∞ were estimated from blood samples collected at several time points within 24 h post-administration of a single 100-mg tablet of sildenafil citrate (Viagra®). Pharmacokinetic data of sildenafil generic 100-mg tablet (product B) was determined in the volunteers using the same analytical method. Pharmacokinetic data of other studies published on different ethnicities were obtained and compared to our Viagra®-related data.ResultsAnalysis of Middle Eastern data (mean ± SD) revealed C_max = 398.9 ± 107.7 ng/ml; T_max = 1.84 ± 0.22 h; t_1/2 = 2.66 ± 0.97 h; AUC_0–24 = 1475 ± 515.3 ng.h/ml; AUC_0-∞ = 1556 ± 567.58 ng.h/ml. There was no significant difference between Viagra® and product B, confirming the bioequivalence of the two preparation as well as the reliability of utilized analytical method. Data comparisons between Middle Eastern and other ethnicities indicated that Iranian, Mexican, and Thai would potentially have twice the effect observed in Arabs and Caucasians, considering the same prescribed drug formulation and dose.ConclusionThere is a considerable difference in the pharmacokinetic profile of sildenafil citrate between Middle Eastern and other ethnic groups. Ethnicity may predispose individuals to unwanted prolonged activity of sildenafil and adverse events. Thus, it should be taken in consideration by clinicians when recommending sildenafil dose.