HPLC/MS研究国产盐酸班布特罗片及其代谢物特布他林人体生物等效性

目的研究国产班布特罗片剂和进口片剂进行人体生物等效性研究。方法20名健康受试者随机交叉给药,用液相色谱/质谱联用测定血浆中班布特罗其代谢物特布他林的浓度。结果经数据处理,单次口服国产和进口班布特罗片剂后班布特罗的药代动力学参数:AUC_0-t分别为(52±21)μg·h·L^-1和(51±20)μg·h·L^-1,T_max分别为(2.9±0.9)h和(2.6±0.7)h,C_max分别为(6.0±2.6)μg·L^-1和(6.2±2.9)μg·L^-1。特布他林:AUC_0-t分别为(191±30)μg·h·L^-1和(197±37)μg·h·L^-1,T_max分别为(4.2±1.0)h和(4.2±1.0)h,C_max分别为(10±5)μg·L^-1和(10±4)μg·L^-1。国产班布特罗片剂单次给药后的相对生物利用度为102%±8%(班布特罗),100%±12%(特布他林)。结论经统计学证明两制剂有生物等效性。     

高效毛细管电泳法研究盐酸班布特罗国产胶囊与进口片剂的人体生物等效性高效毛细管电泳法研究盐酸班布特罗国产胶囊与进口片剂的人体生物等效性

目的研究国产盐酸班布特罗胶囊和进口片剂的人体生物等效性。方法采用高效毛细管电泳法测定血浆中班布特罗及其代谢物特布他林的浓度。结果单次口服国产班布特罗胶囊和进口班布特罗片剂后班布特罗的药代动力学参数:AUC0-t分别为(71±18)和(72±13) μg·h·L^-1,实测C_max分别为(8.1±1.8)和(9.2±2.3) μg·L^-1,实测t_max分别为(3.6±1.3)和(3.7±1.0) h。特布他林药代动力学参数:AUC0-t分别为(129±33)和(130±34) μg·h·L^-1,实测C_max分别为(7.8±2.3)和(8.5±2.9) μg·L^-1,实测t_max分别为(5.4±0.8)和(5.6±1.1) h,国产班布特罗胶囊单次给药后的相对生物利用度为(100±16)%(班布特罗),(101±13)%(特布他林)。结论经统计学证明两制剂具有生物等效性。     

手性和非手性联用色谱法研究尼卡地平对映异构体兔体内过程的差异性

目的研究尼卡地平(NCD)对映体在家兔体内药代动力学和组织分布的差异性。方法生物样品在碱性条件下,正己烷-醋酸乙酯(1:1)提取,用手性和非手性联用色谱法进行分离分析。结果尼卡地平及其对映体分别在反相色谱系统及手性色谱系统中分离良好,浓度为55-550ng·mL^-1线性关系良好。对映体的平均日内、日间RSD分别为5.25%和8.97%,回收率分别为99.99%和97.10%;对映体间主要动力学参数T_max,C_max和AUC,S-NCD为(2.49±0.03)h,(134±2)ng·mL^-1和(1082±32)ng·mL^-1·h,R-NCD为(1.24±0.05)h,(109±2)ng·mL^-1和(778±22)ng·mL^-1·h;在主要脏器和细胞中S-NCD的浓度明显高于R-NCD。药代动力学和靶组织分布均有一定差异性。结论尼卡地平对映体兔体内过程包括代谢动力学和靶细胞浓度分布存在着立体差异性。     

普卢利沙星片的健康人体药动学

目的 健康志愿受试者口服普卢利沙星片后,测定血浆中其活性代谢物(UFX)并作药动学研究。方法 10名受试者分别单剂量和多剂量稳态时服用普卢利沙星片(相当于200 mg UFX),采集血浆和尿液样品,液相色谱分离荧光检测UFX浓度,3P97软件计算药动学参数。结果 单剂量时测得UFX的主要药动学参数分别为c_max(1.64±0.29)μg·ml^-1,t_max(0.7±0.2)h,AUC_0-36(6.87±1.78)h·μg·ml^-1,AUC_0-∞(7.14±1.79)h·μg·ml^-1,t_1/2(7.54±0.59)h,MRT(8.76±0.65)h;0～36 h尿液累积排泄量为(56.85±9.12)%。稳态时测得UFX的主要药动学参数分别为c_max(1.26±0.41)μg·ml^-1,t_max(0.8±0.3)h,AUC_0-36(7.77±2.73)h·μg·ml^-1,AUC_0-∞(8.10±2.70)h·μg·ml^-1,t_1/2(7.71±1.13)h,MRT(9.85±1.40)h。结论 健康志愿受试者口服普卢利沙星片后,在体内转化为活性代谢物(UFX)发挥作用,主要经尿液排泄。每日2次,每次2片(相当于200mg UFX),在体内无积蓄。男女健康受试者的主要药动学参数无显著性差异。     

人血浆中O-去甲右美沙芬的测定及药代动力学研究

目的建立直接测定人血浆中O-去甲右美沙芬的方法,并应用于药代动力学研究。方法18名健康受试者单剂量po氢溴酸右美沙芬60 mg后,血浆样品经液-液萃取,通过液相色谱-质谱-质谱联用法测定其活性代谢物O-去甲右美沙芬的浓度,用非室模型计算药代动力学参数。结果O-去甲右美沙芬测定的线性范围为0.2～80 μg·L^-1;其主要药代动力学参数T_max为(2.1±0.7) h,C_max为(14±8) μg·L^-1,T_1/2为(3.8±1.8) h,用梯形法计算,AUC_0-t为(60±37) μg·h·L^-1。结论该法灵敏度高,操作简便,可直接测定活性代谢物,适用于右美沙芬的临床药代动力学研究及制剂的生物等效性评价。     

HPLC法测定国产洛索洛芬钠片人体相对生物利用度

目的 建立人血浆中洛索洛芬钠浓度的HPLC测定方法,研究健康受试者口服国产洛索洛芬钠片的药代动力学,以进口洛索洛芬钠片作为参比制剂,计算两制剂的相对生物利用度,判断两种制剂是否等效。方法 血浆样品加入内标后经三氯乙酸沉淀蛋白、涡旋、离心,吸取上清液进样。色谱柱为Shimadzu VP-ODS(150mm×4.6mm i.d.,5μm C₁₈),流动相为0.05mol·L^-1磷酸二氢钾-甲醇(27∶73)(v/v),紫外检测波长230nm。测定了20名受试者单剂量口服两种洛索洛芬钠片60mg后血药浓度时间过程。结果 最低检测浓度0.2μg·ml^-1,回收率大于80%,日间和日内的变异系数小于10.5%,线性范围为0.2～12.0μg·ml^-1(r=0.9998),符合生物样品分析的要求。主要药动学参数分别为:国产洛索洛芬钠片:t_1/2为1.39±0.15h,AUC_0-6h 10.71±1.45μg·h·ml^-1,C_max7.23±1.02μg·ml^-1,t_max0.4±0.1h；参比制剂t_1/2为1.41±0.15h,AUC_0-6h 10.46±1.32μg·h·ml^-1,C_max7.49±1.26μg·ml^-1,t_max0.4±0.1h。结论 建立的HPLC法简单快速，定量可靠准确，适合于洛索洛芬钠临床研究。洛索洛芬钠受试制剂的相对生物利用度为（103.2±15.1）%。经统计学分析，两制剂生物等效。     

家犬单剂量和多剂量口服阿昔莫司缓释制剂的药代动力学和生物等效性研究

目的研究阿昔莫司缓释片在家犬体内单剂量和多剂量的药代动力学和生物等效性。方法测定6只家犬单剂量和多剂量口服缓释片和普通胶囊后的血药浓度。结果阿昔莫司的药-时曲线符合非隔室模型。单剂量给药后，缓释片和普通胶囊的AUC分别为(158±30)和(147±37) μg·h·mL^-1；T_max分别为(4.3±0.8)和(2.6±1.3) h；C_max分别为(29±6)和(42±10) μg·mL^-1；T_1/2分别为(2.3±0.7)和(1.60±0.10) h；MRT分别为(6.0±0.8)和(3.9±0.7) h；F_r为(108±16)%。多剂量给药后，缓释片和普通胶囊的AUC分别为(209±23)和(195±26) μg·h·mL^-1；T_max分别为(6.3±0.8)和(3.4±1.5) h；C_max分别为(27±4)和(36±5) μg·mL^-1；Cmin分别为(2.2±1.0)和(0.20±0.20) μg·mL^-1；C_av分别为(8.7±1.0)和(8.1±1.1) μg·mL^-1；FI分别为(293±73)%和(448±91)%；F_r为(114±19)%。结论单剂量实验的双单侧检验结果表明：缓释片和普通胶囊生物等效；缓释片具有良好的缓释效果。多剂量实验结果表明：缓释片和普通胶囊生物等效；缓释片的波动系数优于普通胶囊。     

阿奇霉素在中国健康人体血浆中的药动学研究

目的研究阿奇霉素在健康中国人体中的血浆药动学,为临床用药提供参考。方法10名健康志愿者单剂量口服阿奇霉素500mg后,高效液相色谱-紫外检测法测定血浆药物浓度。采用F检验结合AIC法判别房室模型,DAS药动学程序计算药动学参数。结果最佳房室模型为二室模型(W_i=1/C²,AIC_min=-7.4821),主要的药动学参数:α为(0.29±0.13)h^-1,β为(0.02±0.003)h^-1,K_a为(0.72±0.22)h^-1,t_1/2β为(38.93±7.74)h,t_max为(2.60±0.49)h,c_max为(434.74±47.65)μg·L^-1,AUC_0～144和AUC_0～∞分别为(12179.42±3001.11)μg.h·L^-1和(13338.35±3062.56)μg·h·L^-1。结论阿奇霉素片在中国健康人体中的血浆药动学参数与国内外文献报道基本一致。     

两种国产格列齐特片人体生物利用度的研究

目的 比较两种格列齐特片的生物等效性。方法 用HPLC法测定血浆中格列齐特浓度,研究8名受试者口服两种国产片剂的药动学和生物利用度,并用方差分析和双单侧检验及90%可信限考察生物等效性。结果 8名受试者口服单剂量格列齐特片的药动学参数,试验品的t_max3.38±0.52h,C_max19.91±3.61μg·ml^-1,t_1/26.52±2.40h,AUC 278.86±94.74μg·h·ml^-1;对照品的t_max3.38±0.52h,C_max17.59±3.13μg·ml^-1,t_1/27.77±3.34h,AUC 300.94±87.49μg·h·ml^-1,相对生物利用度为92.46±10.47%。结论 两种片剂经统计分析,C_max的90%可信区间在79.1～99.6%,AUC的可信区间在105.8%～107.4%,这两种片剂完全生物等效。     

高效液相色谱法测定大鼠血浆和子宫中黄体酮及其代谢物的浓度

目的建立高效液相色谱法测定大鼠血浆和子宫样品中的黄体酮及其代谢物20α-羟基黄体酮,并研究大鼠肌肉注射黄体酮后血浆和子宫中的药物代谢动力学。方法样品经液-液萃取后,以乙腈-水(60∶40,pH 4.0)为流动相,用ODS柱进行分离,240 nm检测。以18-甲基炔诺酮为内标。结果血浆中黄体酮C_max为(508±62) μg·L^-1,T_max为(3.2±0.4) h,T_1/2(k_e)为(10±4) h,AUC_0-48h为(5 886±1 573) μg·L^-1·h,子宫中黄体酮T_max为(5.2±1.1) h,C_max(1.7±1.1) μg·g^-1。20α-羟基黄体酮具有与黄体酮相似的T_max。结论该方法简便、准确,可同时测定黄体酮和代谢物,适用于黄体酮及其代谢物20α-羟基黄体酮的药代动力学研究。     

Pharmacokinetic difference between S-（＋）- and R-（-）-etodolac in rats

AIM: To study whether etodolac enantiomers have pharmacokinetic difference after oral administration. METHODS: Fourteen rats, divided into two groups randomly, were orally given S-( )- or R-(-)-etodolac at a single dose of 20 mg/kg, respectively. Blood samples were collected before and at 5, 10, 20, 30 min and 1, 3, 6, 12, 24, 48, 72 h after treatment. The plasma samples were analyzed with a high-performance liquid chromatographic method. RESULTS: The calibration curves were linear in the range of 0.5-50.0 mg/L (r=0.9999) to S-( )-etodolac and 2.0-200.0 mg/L (r=0.9999) to R-(-)-etodolac, respectively. The main pharmacokinetic parameters of S-( )- and R-(-)-etodolac were as follows: t1/2(λz)18±4 h vs 19.4±2.2 h, tmax 3.3±2.6 h vs 4±4 h; Cmax 29±6 mg/L vs97±14 mg/L, AUC0-t 706±100 h·mg·L-1 vs 2940±400 h·mg·L-1, CL(s) 0.030±0.006 L·kg-1·h-1 vs 0.0065±0.0010 L·kg-1·h-1 and V/F 0.25±0.22 L·kg-1 vs 0.03±0.05 L·kg-1. There was no significant difference in t1/2(λz) and tmax between S-( )-     

HPLC万古霉素手性柱和手性流动相添加剂法分离酮洛芬对映体

目的以万古霉素为手性选择子,建立酮洛芬对映体以手性柱法和流动相添加剂法进行手性分析的方法。方法考察万古霉素用量、有机改性剂用量及缓冲液pH值对酮洛芬对映体手性拆分的影响,并进行了定量分析的方法验证。结果两种拆分方法都使酮洛芬对映体达到了基线分离,都适合于酮洛芬对映体的定性和定量分析。结论所建立的两种方法均可用于S-(+)-酮洛芬的光学纯度检测。     

Pharmacokinetic behavior and tissue distribution of verapamil and its enantiomers in rats by HPLC

The differences in pharmacokinetic behavior and tissue distribution of verapamil and its enantiomers were investigated in rats. In high-performance liquid chromatographic method, an achiral ODS column (150 mm x 4.6 mm i.d.) with the mobile phase consisting of methanol-water (73:30, v/v) was used for the determination of the concentration for racemic verapamil, and a Chiralcel OJ column (250 mmx4.6 mm i.d.) with the mixture of n-haxane-ethanol-triethylamine (85:15:0.2, v/v/v) as mobile phase was used to determine the concentrations of verapamil enantiomers. A fluorescence detector in the analytical system was set at excitation and emission wavelengths of 275 nm and 315 nm. The differences between enantiomers were apparent in the pharmacokinetics in rats. The area under the concentration-time curve (AUC) of S-(-) verapamil was higher than that of R-(+) verapamil. The half-distribution time (T 1/2(alpha)) of S-(-) verapamil which distributing to tissue from blood was shorter than that of R-(+) verapamil, but the elimination half-time (T 1/2(beta)) was longer in rat following oral administration of racemic verapamil. At 1.3 h after oral administration of racemic verapamil, however, there were no significant differences between enantiomers for the distributions in major tissues such as heart, cerebrum, cerebellum, liver, spleen and kidney.     

Pharmacokinetics of ofloxacin enantiomers after intravenous administration for antibiotic prophylaxis in biliary surgery

The pharmacokinetics of S-(-)- and R-(+)-ofloxacin, enantiomers of the fluoroquinolone ofloxacin, were characterized after prophylactic administration in 15 patients undergoing elective biliary surgery. A single dose of ofloxacin 400 mg given intravenously as an infusion was administered 1 hour before surgery. Plasma levels of S-(-)- and R-(+)-ofloxacin showed very small differences between both enantiomers, although the ratio of S-(-)- to R-(+)-enantiomer concentration in plasma showed significant differences (p < 0.05) at 4 and 12 hours. Adequate S-(-)-ofloxacin (levofloxacin, the active enantiomer) plasma levels (> or = minimum inhibitory concentration [MIC90] for Escherichia coli) were found throughout the procedure. For pharmacokinetic parameters, the authors found small but statistically significant differences (p < 0.05) in the area under the concentration-time curve, AUC0-infinity (22.30 +/- 2.72 mg h/L for S-(-)-ofloxacin vs. 20.50 +/- 2.06 mg h/L for R-(+)-ofloxacin), and in the clearance (0.15 +/- 0.04 L/h/Kg for S-(-)-ofloxacin vs. 0.16 +/- 0.04 L/h/Kg for R-(+)-ofloxacin). To test the penetration of ofloxacin enantiomers into tissues, the authors measured levels in subcutaneous cell tissue and gall-bladder cell tissue. They did not observe statistical differences between the two isomers, which means that distribution is not an estereoselective process. Enantiomer levels in these two tissues decreased rapidly, but the highest concentrations were reached during the 4 first hours (i.e., when the surgical procedure was being performed). In conclusion, with the prophylactic treatment used, levofloxacin plasma and tissue levels are high enough to prevent surgical infections.     

Relationship between the stereoselective negative inotropic effects of verapamil enantiomers and their binding to putative calcium channels in human heart.

Ventricular preparations from patients with mitral disease and hypertrophic obstructive cardiomyopathy (HOCM) were set up to contract isometrically. Ventricular membrane particles were also prepared and putative calcium channels were labelled with [3H]-nimodipine. Positive staircase was induced by varying the rate of stimulation of isolated strips from 6 min-1 to 120 min-1 in the presence of 6-60 microM (-)-adrenaline or (-)-noradrenaline. (-)-Verapamil 3-5 microM or (+)-verapamil 20-30 microM reversed the force-frequency relationship (i.e. caused negative staircase) in preparations from patients with mitral disease or HOCM. In subendocardial strips of ventricular septum from 5 patients with HOCM paced at 60 min-1, both (-)-verapamil and (+)-verapamil caused cardiodepression. Half-maximal cardiodepression was observed with 0.4 microM (-)-verapamil and with 3 microM (+)-verapamil. [3H]-nimodipine bound to ventricular membrane particles in a saturable, reversible fashion to a high affinity site with an equilibrium dissociation constant of 0.23 nM. The density of these sites was 95 fmol mg-1 of membrane protein. Binding of the tritiated 1,4-dihydropyridine was stereoselectively inhibited by 1,4-dihydropyridine enantiomers and nifedipine. (-)-Verapamil and (+)-verapamil inhibited high affinity [3H]-nimodipine binding in a negative heterotropic allosteric manner with (-)-verapamil being 5 times more potent than (+)-verapamil on an IC50 basis. At a given [3H]-nimodipine concentration, (+)-verapamil inhibited a greater fraction of specific [3H]-nimodipine binding. The allosteric mode of (+)-verapamil inhibition of [3H]-nimodipine binding was confirmed by kinetic studies. (-)-Verapamil shifted (+)-verapamil-binding inhibition curves to the right in an apparently competitive fashion. The inversion of staircase caused by both verapamil enantiomers suggests that they cause a use-dependent channel blockade. The similar potency ratios for binding and for cardiodepression are indicative of a common locus of action for both verapamil enantiomers within the calcium channel.     

Species-dependent stereopharmacokinetics of MK-927, a potent carbonic anhydrase inhibitor.

MK-927 [5,6-dihydro-4H-4(isobutylamino)thieno(2,3-B)thiopyran-2-sul fonamide -7,7 dioxide], a potent carbonic anhydrase inhibitor, contains a chiral center and is a mixture of two forms, R-(-)- and S-(+)-enantiomer. The latter has recently been designated as MK-417. Following iv administration of each enantiomer (0.05 mg/kg), dogs, rabbits, and rats cleared the R-(-)-enantiomer more rapidly than the S-(+)-enantiomer. The elimination clearance of the R-(-)-enantiomer was 2.01 +/- 0.34, 30.0 +/- 2.1, and 53.6 +/- 6.4 ml/hr/kg for dogs, rabbits, and rats, respectively. The corresponding values for the S-(+)-isomer were 0.0380 +/- 0.008, 1.15 +/- 0.20, and 1.29 +/- 0.09 ml/hr/kg. The ratio of the clearance of the R-(-)-enantiomer to that of the S-(+)-isomer was approximately 53 for the dog, 42 for the rat, and 26 for the rabbit, indicating that the degree of stereoselectivity in elimination kinetics of MK-927 enantiomers was species-dependent. Binding of the enantiomers to erythrocytes, presumably carbonic anhydrase, was also stereoselective and species-dependent; the S-(+)-enantiomer was bound more strongly than the R-(-)-isomer in all species. For both enantiomers, binding to carbonic anhydrase was found to be more extensive in dogs than in other species studied. The elimination clearance of the enantiomers in all species was roughly related to their binding affinity, greater Kd1 values being associated with more rapid clearance. However, binding data alone cannot quantitatively explain the degree of the species-dependent stereoselectivity in the elimination kinetics; other factors may also contribute.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stereoselective disposition of mexiletine in man.

The pharmacokinetics of S-(+)- and R-(-)-mexiletine and of the corresponding conjugates were investigated in six healthy young volunteers after administration of a single 200 mg oral dose of racemic mexiletine hydrochloride. The values for the distribution rate constants as well as for the elimination half-lives of the two enantiomers were similar but the AUC of the S-(+)-enantiomer was always significantly higher (P less than 0.01) than that of the opposite enantiomer. The mean R/S ratios for unchanged mexiletine in serum and in urine were 0.78 +/- 0.12 (s.d.) and 0.80 +/- 0.21, respectively. Urinary excretion of mexiletine conjugates consisted mainly of the R-(-)-enantiomer; the mean R/S enantiomeric ratio over 48 h was 9.65 +/- 3.10. Serum concentrations of the conjugates were measured in three subjects. The mean R/S AUC ratio was 2.94 +/- 0.48 and the renal clearance of the R-(-)-enantiomer was significantly higher (P less than 0.02) than that of the S-(+)-enantiomer.     

Age-dependent stereoselective increase in the oral clearance of hexobarbitone isomers caused by rifampicin.

1. The disposition of hexobarbitone enantiomers before and after rifampicin treatment (600 mg daily for 14 days) was investigated in six young (29 +/- 3 years old) and six elderly (71 +/- 4 years old) healthy male volunteers. Hexobarbitone was given as a single 500 mg oral dose of the racemate. 2. The mean (+/- s.d.) oral clearance of S-(+) hexobarbitone was 1.9 +/- 0.3 and 1.8 +/- 0.2 ml min-1 kg-1, respectively, in young and elderly subjects and increased approximately six fold following 14 days of rifampicin treatment in both young (to 11.9 +/- 2.2 ml min-1 kg-1) and elderly (to 10.7 +/- 2.8 ml min-1 kg-1) subjects. 3. In contrast, rifampicin treatment produced a larger and a differential increase in the oral clearance of R-(-) hexobarbitone in young and elderly subjects; an 89 fold change in the young (15.6 +/- 16.4 to 1146.7 +/- 1478.0 ml min-1 kg-1) and a 19 fold change (10.3 +/- 3.0 to 199.9 +/- 98.1 ml min-1 kg-1) in the elderly.     

Pharmacokinetic interaction of ibuprofen enantiomers in rabbits

The potential interaction between two ibuprofen enantiomers was studied after intravenous administration of R-(-)-, S-(+)- and racemic ibuprofen to rabbits. The total body clearance values calculated by compartmental model analysis (0.65 +/- 0.21 for R-(-)-ibuprofen and 0.63 +/- 0.34 for S-(+)-ibuprofen) after intravenous administration of the racemate of ibuprofen were significantly smaller than those of individual enantiomers (0.95 +/- 0.23 for R-(-)-ibuprofen and 1.03 +/- 0.23 for S-(+)-ibuprofen), indicating that the enantiomer-enantiomer interaction results in a mutual inhibition. The enantiomeric interaction in the pharmacokinetic behaviour of ibuprofen after racemic administration is considered to be a result of an alteration in the metabolic or excretion phase (or both) rather than stereoselective protein binding in the systemic distribution.     

The difference between nicardipine and its enantiomers on inhibiting vasoconstriction of isolated rabbit thoracic artery

The present study was designed to study the difference effects between nicardipine and its two enantiomers on thoracic artery of rabbit. A high-performance liquid chromatographic method was used to prepare the two enantiomers of nicardipine. The thoracic artery of rabbit was removed. The vessels were cut into 3 mm in width and 15 mm in length spiral strips and immersed into tissue baths. The concentration-response curves of nicardipine and its enantiomers were obtained by cumulative administration of the vasoconstrictors. Nicardipine and the enantiomers could shift the dose-response curves of NE, KCl or CaCl2 to right in a nonparallel manner and decrease the maximum effective in a concentration-depended manner, respectively. The pD2' value of R-(-)-nicardipine showed significantly effective than that of nicardipine and S-(+)-nicardipine (P<0.01). There was not obviouse difference between the pD2' value of nicardipine and S-(+)-nicardipine (P>0.05). The results demonstrate that the stereoselective interaction between R-(-)-nicardipine and L-calcium channel receptor is more stronger than that of S-(+)-nicardipine.