不同甲状腺机能状态对地西泮药代动力学的影响

用大鼠建立甲状腺机能低下(甲低)和甲状腺机能亢进(甲亢)的动物模型。以HPLC法测定地西泮血药浓度,研究甲低和甲亢对地西泮药代动力学的影响。结果表明,甲低组大鼠地西泮血药浓度显著高于对照组(P<0.05),Cmax升高,AUC增大,吸收T_1/2延长,Vd减小,消除减慢。轻度甲亢组地西泮血药浓度、Cmax及AUC与对照组相比无差异,但随着甲亢程度加重,上述指标逐渐增高。轻、中度甲亢组地西泮吸收基本不变,Vd减小,消除加快;重度甲亢组吸收明显加快,Vd减小,消除减慢。提示不同甲状腺机能状态对地西泮药代动力学的影响不同。     

Pharmacokinetic studies on micronomicin in dogs. Comparison of intramuscular and drip intravenous administration models

The pharmacokinetics of micronomicin (MCR) were studied in dogs after intramuscular (i.m.) and drip intravenous (d.i.v., 0.5, 1 and 2 hours) administration (10 mg/kg). After i.m. administration, the plasma levels of MCR followed a one-compartment open model, and after d.i.v. administration it followed a two-compartment open model. The peak plasma levels of MCR after i.m., 0.5, 1 and 2 hours d.i.v. administration were 28.7 +/- 6.5, 36.7 +/- 3.6, 30.2 +/- 5.1 and 20.3 +/- 2.3 mcg/ml, respectively. The pharmacokinetic parameters (T1/2, AUC, Kel, Vd and Cl) of MCR except Cmax and Tmax were not differentiated by the route of administration. Urinary recovery of MCR after d.i.v. administration was equal to that of MCR after i.m. administration.     

Pharmacokinetics of m-nisoldipine in rabbits and rats

A reverse phase HPLC method was devised for determination of m-Nis in plasma. A mobile phase of methanol-KH2PO4 with a flow rate of 1 ml/min was used. Diazepam was used as the internal standard. A two-compartment model featured the pharmacokinetic process of m-Nis after its iv injection to rats (30 micrograms/kg) and rabbits (50 micrograms/kg). The pharmacokinetic parameters were: T 1/2 alpha = 4.3 min, T 1/2 beta = 63.6 min, Vd = 0.805 L/kg, Cl = 9 ml/(min.kg) in rats; T 1/2 alpha = 5.0 min, T 1/2 beta = 78.3 min, Vd = 1.191 L/kg, Cl = 11 ml/(min.kg) in rabbits. The pharmacokinetics for m-Nis after ig 200 micrograms/kg to rats described one-compartment model with parameters: T 1/2 = 84.8 min, Tmax = 31.2 min, Cmax = 49.97 micrograms/L, Vd = 0.792 L/kg and Cl = 25 ml/(min.kg).     

63Ni-NiCl2在大鼠体内的药代动力学及其组织残留

镍是动物体必需的微量元素,参与核酸和蛋白质的代谢、激素的调节过程,具有刺激生血、促进红细胞再生的功能[1],与激素、蛋白质和脂类的代谢也密切相关.国内相关研究较少,尤其使用同位素标记法研究更少.     

依普黄酮固体分散体在大鼠的药物动力学评价

AIM: To evaluate pharmacokinetic behavior of ipriflavone solid dispersion in rats. METHODS: The plasma concentrations of ipriflavone in rats were determined by HPLC with UV detector. RESULTS: Plasma concentration-time curves after ig ipriflavone solid dispersion 250 mg.kg-1 in rats were fitted with one-compartment model. Pharmacokinetic parameters were as follows: Ke = 0.21 h-1, T1/2Ke = 5.19 h, Ka = 1.71 h-1, T1/2Ka = 0.41 h, Tmax = 0.67 h, Cmax = 429 micrograms.L-1, AUC = 3916 micrograms.h.L-1; The relative bioavailability of ipriflavone solid dispersion was 323%. CONCLUSION: Ipriflavone in solid dispersion was absorbed more effectively than that in physical mixture in rats.     

丙磺舒对大鼠体内头孢克罗药动学的影响

目的 :观察不同剂量丙磺舒对大鼠体内头孢克罗药动学的影响。方法 :大鼠 2 4只随机分成 4组 ,Ⅰ组 :单用头孢克罗 10 0mg·kg-1;Ⅱ组 :头孢克罗 10 0mg·kg-1联用丙磺舒 30 0mg·kg-1;Ⅲ组 :头孢克罗 10 0mg·kg-1联用丙磺舒 6 0 0mg·kg-1;Ⅳ组 :头孢克罗 10 0mg·kg-1联用丙磺舒 90 0mg·kg-1。各组动物灌胃给药后不同时间取血 ,HPLC法测头孢克罗血药浓度 ,DAS程序计算药动学参数。结果 :联用剂量在 30 0～ 6 0 0mg·kg-1范围内 ,随丙磺舒联用剂量增大 ,头孢克罗的Cmax、AUC增高而CL F、V F减少 ;当丙磺舒联用剂量达 90 0mg·kg-1时 ,头孢克罗的Cmax反而降低 ,而AUC、CL F则稳定于联用丙磺舒6 0 0mg·kg-1时的水平。结论 :丙磺舒可明显改变头孢克罗的药动学 ,在本实验剂量范围内其影响程度与丙磺舒剂量有关 ,随丙磺舒联用剂量增大 ,头孢克罗的Cmax先升高后降低 ,该现象可能与大剂量丙磺舒抑制头孢克罗的肠吸收有关。     

Prediction of steady-state bioequivalence relationships using single dose data I-linear kinetics

Simulated data using a linear one- and two-compartment body model with different absorption characteristics were used to evaluate the ability of single dose bioavailability data to predict the relationships that exist at steady state. This was done by comparing the confidence intervals obtained from single and multiple dose data sets for the parameters of Tmax, Cmax, and area under the curve from time zero to infinity (AUC0-infinity). As a consequence of Tmax and Cmax decreasing and increasing from single to multiple dosing regimens, the confidence intervals for these parameters reflected these changes. The 90 per cent confidence interval expressed as a percentage of the reference mean increased or decreased for Tmax dependent upon the ratio of Ka test/Ka reference, and decreased for Cmax while the interval for AUC0-infinity exhibited no predictable pattern and appeared to be influenced by the amount of error in the data set. Alteration of either the dosing interval or the fraction absorbed did not affect the pattern of change in the confidence intervals for Tmax and Cmax, but the latter did result in a decrease in the interval for AUC0-infinity. Analysis of the confidence intervals for Tmax, Cmax and AUC0-infinity in bioequivalency studies for quinidine gluconate and procainamide hydrochloride following administration of single and multiple doses to different subjects appeared to be consistent with the patterns observed for the simulated data sets.     

尼群地平对6例高血压病人的药物动力学和药效学

以反相高效液相色谱内标定量法对6名原发性高血压志愿受试者口服尼群地平0.5mg/kg进行药物动力学和药效学研究。血药浓度-时间曲线为二室开放模型;药动学参数:Ka=0.71±0.15h~(-1),T_(max)=1.5h,C_(max)=67ng/mL。血药浓度与血压下降明显相关(r=-0.819);最大作用维持时间为2-6h。     

尼可地尔口腔速溶片的研究

目的　制备尼可地尔口腔速溶片以提高其生物利用度和改善药物的苦味。方法　用croscarmellosesodium ,D-甘露醇和乳糖制备直径为6mm(崩解时限为12s)和10 mm(崩解时限为23s)的尼可地尔口腔速溶片。对其崩解性能、硬度、药物释放度、体内吸收及口感性能进行了考察。结果　压力在1.37×10⁸ Pa以上,甘露醇-乳糖比为9∶1,croscarmellosesodium的添加量为1% - 4%时,口腔速溶片的崩解时间较市售片缩短了1/3,且能达到一定的硬度。对Beagle犬经口服给药后,测得血药浓度与市售片相同,AUC ,C_max,T_max值无明显差异。口腔速溶片有长效和掩盖药物苦味的作用,同时甜味剂对掩盖药物苦味有相加作用。结论　口腔速溶片为快速崩解型片剂,与市售片等效,适合老龄和小儿患者服用     

The pharmacokinetic studies on astromicin in dogs. Intramuscular, intravenous or drip intravenous administration

The pharmacokinetics of astromicin (ASTM), a new aminoglycoside antibiotics, was studied in dogs after intramuscular (i.m.), intravenous (i.v.) or drip intravenous (d.i.v.: for 0.5, 1 hr. or 2 hrs.) administration at a dose of 20 mg/kg. The pharmacokinetic parameters were calculated using one-compartment open model (i.m.) or two-compartment open model (i.v. and d.i.v.). The peak plasma levels of ASTM were 34.1 mcg/ml (i.m.), 50.5 mcg/ml (d.i.v., 0.5 hr.), 39.8 mcg/ml (d.i.v., 1 hr.) and 28.2 mcg/ml (d.i.v., 2 hrs.), respectively. The pharmacokinetic parameters (T1/2, AUC infinity, Kel, Vd and Cl) of ASTM except Cmax and Tmax were similar for different routes of administration. Urinary recovery rates of ASTM were 90.5% (i.m.), 95.2% (i.v.), 91.6% (d.i.v., 0.5 hr.), 92.6% (d.i.v., 1 hr.) and 93.5% (d.i.v., 2 hrs.) by 24 hours. After intramuscular, intravenous or 1 hour drip intravenous administration of ASTM, no active metabolite was found in urine of dogs.     

Pharmacokinetic studies on oral antibiotics in pediatrics. I. A pharmacokinetic study on cefixime in pediatrics

A pharmacokinetic study on cefixime (CFIX) 5% granules for pediatric use was performed, and pharmacokinetic parameter were calculated. 1. Six school children were administered orally with CFIX granules at a dose level of 3 mg/kg either at 30 minutes before meal or at 30 minutes after meal on a crossover design, and serum concentrations and urinary excretion rates of CFIX were determined. Tmax, Cmax, T 1/2 and urinary excretion rate (0-12 hours) following the administration before meal were 3.33 +/- 0.42 hours, 1.03 +/- 0.17 micrograms/ml, 2.31 +/- 0.26 hours and 15.3 +/- 2.2%, respectively, Tmax, Cmax, T 1/2 and urinary excretion rate following the the administration after meal were 4.00 +/- 0.52 hours, 0.90 +/- 0.09 micrograms/ml, 3.11 +/- 0.21 hours and 11.3 +/- 1.6%, respectively. Earlier Tmax, higher Cmax and higher urinary excretion rate were observed when the drug was administered before meal than when administered after meal. These differences between the 2 groups were not statistically significant. 2. Five school children were administered orally with CFIX granules at 30 minutes after meal at a dose level of either 3 mg/kg or 6 mg/kg on a crossover design, and serum concentrations and urinary excretion rates of CFIX were determined. Cmax and AUC at a dose level of 3 mg/kg were 1.01 +/- 0.26 mg/ml and 5.86 +/- 1.13 micrograms.hr/ml, respectively, and Cmax and AUC at a dose level of 6 mg/kg were 1.76 +/- 0.29 micrograms/ml, 12.54 +/- 1.77 micrograms.hr/ml, respectively. A dose response relationship was thus observed. Seven infants (3 mg/kg) and 3 infants (6 mg/kg) were administered orally with CFIX granules at 30 minutes after meal. Cmax and AUC at a dose level of 3 mg/kg were 2.45 +/- 0.26 micrograms/ml, 33.50 +/- 7.62 micrograms.hr/ml, respectively, and Cmax and AUC at a dose level of 6 mg/kg were 4.42 +/- 0.98 micrograms/ml, 66.85 +/- 25.19 micrograms.hr/ml, respectively. A dose response was observed. 3. Eleven school children, 5 younger children and 7 infants were administered orally with CFIX granules at a dose level of 3 mg/kg at 30 minutes after meal, and serum concentrations and urinary excretion rates of CFIX were determined. Tmax in school children, younger children and infants were 3.82 +/- 0.33 hours, 5.20 +/- 0.49 hours and 5.43 +/- 0.37 hours, respectively. Earlier Tmax's were observed in school children than in other children. Cmax in school children, younger children and infants were 0.95 +/- 0.12 micrograms/ml, 0.56 +/- 0.06 micrograms/ml and 2.45 +/- 0.26 micrograms/ml, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)     

Enhanced bioavailability of paclitaxel by bamboo concentrate administration

The purpose of this study was to investigate the effect of a cotreatment of bamboo concentrates (Jukcho solution; 0.75, 1.5, and 3.0 mL/kg) with the chemotherapeutic agent paclitaxel on the bioavailability of orally administered paclitaxel (50 mg/kg) in rats. The effect of a pretreatment of bamboo concentrates (1.5 and 3.0 mL/kg for 1.0 h or a consecutive 3 day) was also examined. The paclitaxel plasma concentrations of rats orally administered paclitaxel plus bamboo concentrates (coadministration, 3.0 mL/kg and pretreatment, 1.5 and 3.0 mL/kg) were significantly higher than those of rats treated with paclitaxel alone. Plasma concentrations of paclitaxel in groups pretreated with bamboo concentrates for 3 day were markedly higher than those of a paclitaxel control group at the measured time points. The areas under plasma concentration-time curves (AUCs) of paclitaxel in groups pretreated with bamboo concentrates were elevated and the absolute bioavailability (AB%) and relative bioavailability (RB%) of paclitaxel were also significantly higher than those in the control group. The peak concentration (Cmax), half-life (t1/2), and the elimination rate constant (Kel) of paclitaxel after 3 day of pretreatment with bamboo concentrates were also significantly higher than those in the control, but the time required to reach the maximum plasma concentration (Tmax) of paclitaxel was unaffected by the bamboo concentrates. Western blot analyses demonstrated that the level of CYP3A4 was increased in the livers of rats treated orally with paclitaxel, but this was reversed by pretreating with bamboo concentrates. These results show that bamboo concentrates enhance the bioavailability of orally administered paclitaxel and this effect may be associated with a diminished expression of CYP3A4 in the liver.     

Toxicokinetic study of norfloxacin-induced arthropathy in juvenile animals

A toxicokinetic study of norfloxacin-induced arthropathy in juvenile animals was undertaken using nalidixic acid as a standard drug. Norfloxacin and nalidixic acid were subcutaneously administered to rats and rabbits, orally administered to dogs, and norfloxacin was orally dosed to monkeys once a day for 7 consecutive days. Of the dose levels tested, the minimum arthropathic doses of norfloxacin were 100, 25, and 50 mg/kg/day in rats, rabbits, and dogs, respectively. At these doses, the peak serum concentrations (Cmax) on Day 6 were 16.1, 9.73, and 5.11 micrograms/ml, and the areas under the serum concentration/time curve (AUC0----infinity) were 31.9, 22.9, and 26.2 micrograms.hr/ml, in respective animals. Monkeys showed no arthropathy with norfloxacin at doses of less than 500 mg/kg/day, at which the Cmax and AUC0----infinity were 15.6 micrograms/ml and 103 micrograms.hr/ml, respectively. The minimum arthropathic doses of nalidixic acid were 50, 100, and 25 mg/kg/day in rats, rabbits, and dogs, respectively. The Cmax and AUC0----infinity of nalidixic acid were higher than those of norfloxacin in all animals. Joint tissues took up more norfloxacin than nalidixic acid, but when arthropathy was present the articular cartilage concentrations of the two drugs were in the same range. The penetration of norfloxacin into the articular cartilage was the same regardless of the joint's anatomical locations, but differed among species, being highest in rats and lowest in monkeys. The Cmax and AUC0----infinity of norfloxacin in animals at their arthropathic doses were far higher than those measured clinically in children, whereas those of nalidixic acid in animals did not differ much from its clinical parameters.     

Pharmacokinetics and bioavailability of alpha-, gamma- and delta-tocotrienols under different food status

We have investigated the pharmacokinetics and bioavailability of alpha-, gamma- and delta-tocotrienols under fed and fasted conditions in eight healthy volunteers. The volunteers were administered a single oral dose of mixed tocotrienols (300 mg) under fed or fasted conditions. The bioavailability of tocotrienols under the two conditions was compared using the parameters peak plasma concentration (Cmax), time to reach peak plasma concentration (Tmax) and total area under the plasma concentration-time curve (AUC(o-infinity)). A statistically significant difference was observed between the fed and fasted logarithmic transformed values of Cmax (P < 0.01) and AUC(0-infinity) (P < 0.01) for all three tocotrienols. In addition, the 90% confidence intervals for the ratio of the logarithmic transformed AUC(0-infinity) values of alpha-, gamma- and delta-tocotrienols under the fed state over those of the fasted state were found to lie between 2.24-3.40, 2.05-4.09 and 1.59-3.81, respectively, while those of the Cmax were between 2.28-4.39, 2.31-5.87 and 1.52-4.05, respectively. However, no statistically significant difference was observed between the fed and fasted Tmax values of the three homologues. The mean apparent elimination half-life (t(1/2)) of alpha-, gamma- and delta-tocotrienols was estimated to be 4.4, 4.3 and 2.3 h, respectively, being between 4.5- to 8.7-fold shorter than that reported for alpha-tocopherol. No statistically significant difference was observed between the fed and fasted t(1/2) values. The mean apparent volume of distribution (Vd/f) values under the fed state were significantly smaller than those of the fasted state, which could be attributed to increased absorption of the tocotrienols in the fed state.     

Effect of oral activated charcoal on the pharmacokinetics of quinidine and quinine administered intravenously to rabbits

The pharmacokinetics of quinidine and quinine following intravenous administration (10 mg/kg) with and without concurrent treatment with oral activated charcoal was studied in the rabbit. Marked differences were observed in the pharmacokinetic parameters. Compared to quinidine, quinine was characterized by larger volume of distribution (Vd), systemic clearance (Cl) and elimination rate constant (Kel), and smaller half-life of elimination (t1/2), mean residence time (MRT) and area under the curve (AUC). Activated charcoal administered orally (15 g) significantly decreased the serum concentrations of quinidine but not quinine. Furthermore, charcoal treatment significantly enhanced the systemic elimination of quinidine as indicated by the significant increase in Cl and decrease in t1/2, MRT and AUC. By contrast, activated charcoal had no significant effect on the pharmacokinetic parameters of quinine. Differences between quinidine and quinine in respect to the effect of activated charcoal on the systemic elimination of these drugs seem at least, in part, dependent on dispositional factors. The high Cl and Vd of quinine in the rabbit are probably factors that mask the effect of charcoal on the elimination of this drug.     

Effects of nicorandil and verapamil, antianginal agents, on plasma digoxin concentrations in rats and dogs

The effects of equihypotensive doses of nicorandil and verapamil on plasma digoxin concentrations have been assessed in rats and dogs. In a single digoxin dose study, digoxin (1 mg kg-1) alone, or in combination with nicorandil (5 mg kg-1) or verapamil (25 mg kg-1) was given orally to rats. When given chronically to rats, a single dose of digoxin (1 mg kg-1) orally for 7 consecutive days was followed, on day 8, by digoxin alone, or together with nicorandil (5 mg kg-1) or verapamil (25 mg kg-1). In dogs, a loading dose of digoxin (50 micrograms kg-1) was given orally on day 1, then 25 micrograms kg-1 was administered for the following 6 days. On day 8, digoxin (50 micrograms kg-1) was given with nicorandil (5 mg kg-1) or verapamil (20 mg kg-1). In rats, the AUC0-24 and Cmax of plasma digoxin were enhanced significantly by coadministration of verapamil, but not by nicorandil. In dogs, verapamil significantly increased the Cmax of plasma digoxin, but not the AUC. Nicorandil had no effect on either parameter.     

芪嘧啶的药代动力学

本文报告芪嘧啶在大鼠(150 mg/kg)和家兔(100mg/kg)一次ig的药代动力学研究结果。采用分光光度法测定生物样品中的药物浓度,用3P87实用药代动力学程序处理药物浓度数据,并自动算出各项动力学参数和C-T曲线图。主要参数t_(1/2ke),t_(peak),C_(max),CL和V_d在大鼠分别为6.55 h,1.32 h,9.5μg/ml,1.46 L·kg~1·h~1和13.8 L/kg,家兔分别为1.98h,1.00h,7.1μg/ml,4.09L·kg~1·h~(-1)和11.7 L/kg。结果表明药物在大鼠肝中达峰时间短,峰浓度高,清除较慢,在肝、肾含量高于其它组织。由尿粪排泄量小,72 h累计量仅为给药量的11.5％,而且排泄速度慢,一次给药后72 h仍有一定量药物由粪尿排泄。     

Pharmacokinetics of huperzine A in dogs following single intravenous and oral administrations

The pharmacokinetics of huperzine A in dogs after single intravenous and oral administrations was investigated. Concentrations of huperzine A were determined by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic parameters were calculated by non-compartmental methods. After single intravenous administration, the Cmax, T1/2, AUC0-t, AUC0-infinity, CL, Vd and Vss were 5.55 +/- 1.61 microg/L, 5.02 +/- 0.31 h, 16.04 +/- 5.24, 16.49 +/- 5.29 microgh/L, 0.66 +/- 0.19 L/h/kg, 4.76 +/- 1.46, and 3.93 +/- 1.54 L/kg, respectively. After single oral administration, the Cmax, Tmax, T1/2, AUC0-t, AUC0-infinity and oral bioavailability were 2.60 +/- 0.60 microg/L, 1.25 +/- 0.50 h, 5.71 +/- 2.25 h, 12.90 +/- 3.19, 13.78 +/- 3.24 microgh/L, and 94.4 +/- 36.5%, respectively. In conclusion, huperzine A had a rapid and nearly complete oral absorption and was extensively distributed into tissues after drug administration in dogs.     

Influences of exposure to cigarette smoke on concentration of nicorandil in plasma of rats.

Influences of acute exposure to cigarette smoke on plasma concentrations of nicorandil administered orally and parenterally were investigated in rats by HPLC. The animals were exposed to tobacco smoke of two kinds of cigarettes using a smoking machine (i.e., the cigarette smoke contained either low or high nicotine and tar). The plasma concentration of nicorandil administered orally at a dose of 10 mg/kg had a lower absorption phase in two cigarette smoke-exposed groups, particularly in the high nicotine and tar-containing cigarette smoke-exposed group, compared with the nonsmoking control group. The AUC and MRT values in a high nicotine and tar-containing cigarette smoke-exposed group were lower and higher, respectively, than in the nonsmoking control group. However, there was no marked difference in nicorandil plasma concentrations between the cigarette smoke-exposed group and the nonsmoking control group when nicorandil was administered ip or iv at a dose of 5 mg/kg. These results suggest that cigarette smoke exposure causes the suppression or delay of absorption of nicorandil from the gastrointestinal tract.     

Bioequivalence evaluation of two brands of glimepiride 4 mg tablets in healthy subjects

OBJECTIVE: This paper describes a bioequivalence study with two oral glimepiride (4 mg) tablets formulations. The reference preparation was Solosa/Aventis Pharmaceuticals Inc., USA, and the test preparation was Glimepiride/Specifar, Athens, Greece. SUBJECTS, MATERIAL AND METHODS: The study design was open, randomized, two-period, two-sequence, two-treatment with crossover involving 24 healthy male and female subjects. All subjects completed the study. Glimepiride plasma concentrations were measured utilizing a sensitive, reproducible and accurate HPLC method. Pharmacokinetic parameters used to assess bioequivalence were AUC(0_last), AUC(0-inf) for the extent of absorption and Cmax and tmax for the rate of absorption. Statistical evaluation of Cmax, AUC(0_last), and AUC(0-inf) was done after semilogarithmic transformation using a two-way analysis of variance (ANOVA). Tmax values were tested using the distribution-free Hodges-Lehman interval. RESULTS AND CONCLUSION: The parametric 90% confidence intervals for ratio T/R ranged from 90.60-108.00% (point estimate 98.90%) for AUC(0-last), 90.70-107.90% (point estimate 98.90%) for AUC(0-inf) and 86.70-103.70% (point estimate 94.80%) for Cmax, respectively. Based on the results of tmax, Kel and t(1/2), there were no statistically significant differences and the two glimepiride preparations are equivalent with respect to rate and extent of absorption as defined by the European Union bioequivalence requirements.