The interaction between i.v. theophylline and chronic oral dosing with slow release nifedipine in volunteers.

Eight healthy volunteers received a 5 min i.v. infusion of lysine theophylline, equivalent to 197 mg anhydrous theophylline, both before (day 1) and during (day 5) steady state chronic oral dosing with slow release nifedipine 20 mg 12 hourly. A theophylline pharmacokinetic profile was performed on day 1 and day 5 and a nifedipine pharmacokinetic profile was performed on day 4 and day 5. The greatest difference in serum theophylline concentrations was seen at the first sampling time (5 min after completion of the infusion) with a mean concentration of 9.9 mg l-1 during nifedipine administration and 14.6 mg l-1 with theophylline alone. Thereafter, the difference fell to approximately 1 mg l-1 until 6 h when they became almost identical. Repeated measures analysis of variance using the theophylline serum concentrations at each of ten time points over 8 h as the repeated measures showed a small but significant effect of nifedipine (F(1,151) = 7.0, P less than 0.01) on serum theophylline concentrations. Mean volume of distribution (V) rose from 0.33 +/- 0.07 to 0.39 +/- 0.06 1 kg-1 corrected body weight (CBW) in the presence of nifedipine (t = 2.23, P = 0.052). Theophylline clearance, area under the curve to 8 h AUC (0-8), area under the curve to infinity AUC (0-infinity) and elimination half-life (t1/2) did not change appreciably. No statistically significant changes in nifedipine pharmacokinetics occurred in the presence of theophylline.     

硝苯地平缓释片与普通片在健康人体内药动学的比较

目的比较硝苯地平缓释片与硝苯地平普通片在健康人体内药动学。方法 12名男性健康志愿者平均分为2组,分别单剂量口服硝苯地平缓释片与硝苯地平普通片20 mg,用高效液相色谱法检测硝苯地平的血药浓度,并用DAS 2.1软件进行数据处理。结果硝苯地平缓释片与硝苯地平普通片主要药动学参数ρmax分别为(1 247.8±78.4)μg.L-1和(1 896.7±109.2)μg.L-1,tmax分别为(4.6±0.7)h和(2.6±0.9)h,t1/2分别为(8.6±2.8)h和(4.8±1.5)h,AUC0-∞分别为(5 879.3±176.2)μg.h.L-1和(3 724.9±121.3)μg.h.L-1,AUC0-t分别为(4 427.8±131.7)μg.h.L-1和(2 936.5±75.4)μg.h.L-1。结论硝苯地平缓释片的tmax、t1/2长于普通片,AUC0-t、AUC0-∞高于普通片,而ρmax低于普通片,说明硝苯地平缓释片具有良好的缓释效果。     

心痛定片剂与滴丸的人体生物利用度及药代动力学的研究

本文采用高压液相色谱法测定心痛定片剂与滴丸的人体血药浓度。流动相：甲醇（色谱纯）─磷酸盐缓冲液（６０：４０），紫外检测波长２３５ｎｍ，以片剂为标准制剂，滴丸的相对生物利用度为１２２．０％。对片剂与滴丸的ＡＵＣ、Ｃｍａｘ、Ｔｍａｘ作ｔ检验，结果二者之间Ｃｍａｘ、Ｔｍａｘ有显著性差异（Ｐ＜０．０５），ＡＵＣ无显著差异（Ｐ＞０．０５），结果表明滴丸较片剂优良。     

Absolute bioavailability of oral immediate and slow release fluphenazine in healthy volunteers

Objective: The present study was conducted with the aim of investigating the absolute bioavailability of fluphenazine in healthy volunteers after administration of immediate and slow release oral formulations. Methods: The oral dose was 12 mg fluphenazine hydrochloride. The intravenous bolus dose was 2.5 mg. Fourteen healthy volunteers of both sexes were enrolled in this randomised, crossover trial. Twelve volunteers completed the trial according to protocol. Results: The concentration maxima after administration of the slow release formulation were approximately half those measured after the immediate release formulation and were recorded later by a factor of 2 (immediate release: C_max = 2.3 ng⋅ml⁻¹, t_max = 2.8 h; slow release: C_max = 1.2 ng⋅ml⁻¹, t_max = 4.6 h). The concentrations measured 10 min after intravenous bolus administration of 2.5 mg fluphenazine hydrochloride were approximately 100 times higher (261 ng⋅ml⁻¹). The geometric means for the absolute bioavailability of fluphenazine were 2.7% for the immediate release formulation and 3.4% for the slow release formulation. The absolute bioavailability of fluphenazine is thus much lower than previously generally accepted. Received: 14 December 1995/Accepted in revised form: 26 March 1996     

国产氧氟沙星在健康成人中的药物动力学和生物利用度研究

本文采用专一性强、灵敏度高的HPLC 荧光检测法,测定氧氟沙星血、尿浓度。对国产氧氟沙星片在12例健康受试者中进行药物动力学和生物利用度研究。氧氟沙星片口服给药多数人为一房室模型,其主要药动学参数,国产片和进口片分别为:T_(1/2)6.2±1.3和6.1±1.5h;Vd 1.5±0.4和1.6±0.5l/kg;C_(max)8.6±2.5umol/L 和7.9±1.4μmol/L;T_(max)0.6±0.5和0.6±1.0h;Cl_T13±4和12±4 l/min;AUC_(o-∞)76±23和73±21μmol/L·h。其相对生物利用度为104.9±9.9%。     

瑞力芬片剂口服人体药代动力学及生物利用度研究

目的:检测2种萘丁美酮片剂的药代动力学及生物利用度是否有差异.方法:12例男性健康受试者交叉口服2种萘丁美酮片剂,用高效液相色谱法规定服药后120h内的血浆中蔡丁美酮活性代谢物6-甲氧基-2-萘乙酸浓度.结果:测得主要药代动力学参数为;试验片剂Tp=6.41±3.05h,t1/2β=21.77±3.62h,c_(max)=23.73±4.10mg/L,AUC=1.10.67±205.54(mg·h)/L;对照片剂Tp=10.63±5.10h,t1/2β=21.53±4.77h,c_(max)=18.77±5.39mg/L,AUC= 954.10±263.66(mg·h)/L.结论:试验片与对照片相比吸收较快(P=0.012),峰浓度较高(P=0.029),平均相对生物利用度为112.36%,AUC经配对T检验,无显著性差异(P=0.52).     

Circadian variation in theophylline absorption during chronic dosing with a slow release theophylline preparation and the effect of clock time of dosing.

1. Eight volunteers were given seven doses of 200 mg of slow release theophylline at either 11.00 h and 23.00 h (regimen 1) or 17.00 h and 05.00 h (regimen 2). At the time of the sixth dose (60 h) hourly blood sampling was started and continued for 24 h. After at least 1 week volunteers crossed over to the other regimen. 2. Volunteers retired to bed at 23.00 h and arose after the 07.00 h sample during both regimens. 3. During regimen 1 there was a marked rise in mean tmax from 3.3 h after dosing at 11.00 h to 9.3 h after dosing at 23.00 h (P less than 0.001). There was also a fall in AUC(0,12) from 89.9 mg l-1 h after dosing at 11.00 h to 79.0 mg l-1 h after dosing at 23.00 h. There was no difference in mean Cmax values. 4. During regimen 2 these circadian changes were abolished with mean values after both dosing times lying between those observed during regimen 1. 5. A marked delay in absorption occurs at night and cannot be explained by food intake.     

Chronic nifedipine dosing enhances cephalexin bioavailability and intestinal absorption in conscious rats.

Cephalexin, a beta-lactam antibiotic, is rapidly absorbed via the di-and tripeptide intestinal transporters, as for many peptidomimetic drugs. Acute nifedipine has been shown to increase intestinal absorption of several beta-lactams: amoxicillin and cefixime in humans, and cephalexin in the rat. We showed previously that the nervous system was involved in the increasing effect of nifedipine on cephalexin intestinal absorption in anesthetized rats. The aim of the present study was 2-fold: 1) to investigate whether the effect of nifedipine is maintained in conscious rats, and 2) to determine whether the nifedipine effect will persist during chronic nifedipine administration. Acute and chronic oral administration of nifedipine significantly increased oral cephalexin area under the plasma concentration-time curve (34 and 25%, respectively) and maximum concentration in plasma (57 and 51%, respectively), while the distribution and elimination parameters of intra-arterial cephalexin were not affected by acute or chronic nifedipine administration. In conclusion, acute nifedipine effect on intestinal absorption of cephalexin is independent of anesthesia in rats. Since nifedipine could still enhance cephalexin intestinal absorption after a 7-day b.i.d. treatment, it can be envisaged to apply this effect to increase bioavailability of poorly absorbed peptidomimetic drugs in man.     

健康人口服国产洛美沙星片剂的药代动力学

１２名健康男性志愿者，平均年龄２０ａ，分别交叉口服日本产胶囊和国产片剂盐酸洛美沙星３００ｍｇ。用微生物法测定服药后不同时间点取样的血、尿标本，进行药代动力学和相对生物利用度研究。结果表明：口服两药后均能迅速吸收，达峰时间（Ｔｍａｘ）分别为１．１２±０．２８和１．０８±０．５１ｈ；峰浓度（Ｃｍａｘ）为１．５３±０．５３和１．４９±０．３７ｍｇ·Ｌ－１，消除半衰期（Ｔ１／２β）为９．９２±２．４０和１０．４１±２．１７ｈ；二者的药时曲线下面积（ＡＵＣ）分别为１２．９７±２．８９和１１．８０±２．４８ｍｇ·Ｌ－１·ｈ，国产片剂对日本产胶囊洛美沙星的相对生物利用度为９２．５６±１６．１８％。     

吉非罗齐片和胶囊在健康人体内药物动力学和相对生物利用度比较

目的:测定吉非罗齐的体内过程,作出相对生物利用度评价,为临床合理用药提供依据.方法:8名健康受试者交叉口服单剂量古非罗齐片和胶囊后,用HPLC法测定不同时间的血药浓度,经MCPKP软件拟合处理,并计算药物动力学参数.结果:吉非罗齐片和胶囊均符合开放一室模型,T_(max),C_(max),AUC_(0～∞)分别为(1.61±0.49)和(1.66±0.47)h,(37.28±9.71)和(29.97±5.58)μg/ml;(128.48±24.36)和(119.55±19.48)μg/(h·ml).结论:吉非罗齐片剂对胶囊剂的相对生物利用度为107.26%.     

对乙酰氨基酚凝胶在人体的药动学和生物利用度

８名健康男性志愿者交叉服用５００ｍｇ剂量的对乙酰氨基酚凝胶剂和片剂。血药浓度采用ＨＰＬＣ测定。对乙酰氨基酚凝胶剂的药动学参数：Ｔ１／２（Ｋａ）０．３０±０．２２ｈ，Ｔ１／２（Ｋｅ）２．１±０．４ｈ，Ｔｍａｘ１．０±０．４ｈ，Ｃｍａｘ５．１±１．５μｇ／ｍｌ，ＡＵＣ２１±５（μｇ／ｍｌ）·ｈ。这些参数与片剂的相似，凝胶剂相当于片剂的生物利用度为１０５．１％     

多剂量口服盐酸氨溴索缓释胶囊的人体药代动力学及相对生物利用度

目的　研究多剂量口服盐酸氨溴索缓释胶囊的人体药代动力学和相对生物利用度。方法　选择盐酸奎宁为定量内标物 ,采用反相高效液相色谱法测定了多剂量口服 75mg盐酸氨溴索国产缓释胶囊和进口缓释胶囊在健康人体内的盐酸氨溴索血药浓度 ,以考察盐酸氨溴索缓释胶囊多剂量口服达稳态过程和稳态药代动力学特征。结果　 75mg盐酸氨溴索缓释胶囊连续口服d 4起 ,体内盐酸氨溴索血药浓度基本达稳态水平。国产缓释胶囊和进口缓释胶囊的稳态药代动力学参数Tmax分别为 (4 2± 0 7)h和 (4 1± 0 8)h ,Cmax分别为 (2 0 8 73± 31 91) μg·L-1和 (2 12 5 6± 2 9 6 4) μg·L-1,Cmin分别为 30 76± 10 47μg·L-1和 (2 9 80± 10 2 3)μg·L-1,AUCss分别为 (2 113 90± 430 6 0 ) μg·h·L-1和2 0 88 2 2± 40 2 5 2 μg·h·L-1,Cav分别为 (88 0 8± 17 94) μg·L-1和 (87 0 1± 16 77) μg·L-1,DF分别为 (2 0 7± 0 31)和(2 16± 0 37) ,多剂量口服 75mg国产盐酸氨溴索缓释胶囊的相对生物利用度为 10 1 10 %± 6 33 %。结论　盐酸氨溴索国产缓释胶囊和进口缓释胶囊的主要稳态药代动力学参数差异均无显著性 ,两种制剂具有生物等效性     

Acute and chronic pharmacokinetics of asymmetrical doses of slow release choline theophyllinate in asthma.

The day and night pharmacokinetics of assymetrical doses of slow release choline theophyllinate (Sabidal SR 270) were compared at day 1 and at day 4 of treatment when steady state had been achieved. Ten patients with chronic asthma were given oral choline theophyllinate 424 mg at 09.00 h and 848 mg at 21.00 h for 4 days. At regular intervals during day 1 and day 4 of treatment theophylline concentrations were measured in plasma and dried blood spots by fluorimmunoassay. Theophylline concentrations measured from dried blood spots were slightly lower than those in plasma, the difference remaining constant at all time points during day 1 and day 4 of treatment. On day 1 the mean peak plasma theophylline concentration was 5.4 +/- 1.0 (+/- s.e. mean) micrograms ml-1 4 h after the morning dose and 11.2 +/- 1.6 micrograms ml-1 4 h after the evening dose which were significantly (P less than 0.01) different. Similarly the areas under the plasma theophylline concentration-time curves at night were significantly (P less than 0.001) greater than those observed during the day. During day 4 mean peak plasma concentrations of theophylline after the morning and larger evening dose were 13.2 +/- 1.3 and 12.1 +/- 1.4 micrograms ml-1 respectively, which were not significantly different. No significant difference was observed between the areas under the plasma theophylline concentration-time curves during the day and at night. However the post-dose time to peak was significantly delayed at night (6 h) compared to the morning (2 h, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Alinidine pharmacokinetics following acute and chronic dosing.

1 Alinidine (N-allyl clonidine) pharmacokinetics were investigated in healthy volunteers following acute administration of 40 mg orally and intravenously (i.v.) and chronic administration of 40 mg daily and twice daily for 8 days. 2 After acute oral administration the following values were obtained; Cmax -- 166.5 +/- 18.5 ng/ml at 1.8 +/- 0.7 h (mean +/- s.d., n = 5); AUC -- 1122.9 ng ml-1 h; VdSS -- 190.71 and T1/2 -- 4.2 h, and after i.v. administration: AUC -- 1046.7 ng ml-1 h; VdSS -- 190.71 and T1/2 4.2 h. 3 Clonidine was identified in plasma and urine samples following oral and i.v. administration; clonidine Cmax was 0.26 +/- 0.06 ng/ml at 8.4 +/- 2.2 h and 0.5 +/- 0.2 ng/ml at 4.8 +/- 2.5 following oral and i.v. alinidine respectively. Urinary excretion of clonidine represented 0.1% of the administered dose of alinidine. 4 During administration of alinidine 40 mg daily for 8 days, peak and trough plasma levels reached steady state after day 2 (223.1 +/- 123.9 and 9.03 +/- 6.7 ng/ml respectively). During alinidine 40 mg twice daily for 8 days peak and trough plasma levels on day 2 were 356.2 +/- 92.0 and 80.0 +/- 35.8 ng/ml respectively, these levels did not change (P greater than 0.05) between days 2 and 8. Urine elimination of alinidine did not change (P greater than 0.05) between days 5, 6, 7 and 8. 5 Clonidine plasma concentration following alinidine 40 mg daily and twice daily were 0.47 +/- 0.18 and 0.84 +/- 0.21 ng/ml respectively 2 h after administration on day 2 and did not change (P less than 0.05) between days 2-8. 6 It is unlikely that clonidine formed from alinidine contributes to the pharmacological action of alinidine.     

格列吡嗪片在健康志愿者体内的生物等效性评价

目的比较两种格列吡嗪片剂在健康志愿者体内的药动学及生物等效性.方法12例男性健康志愿受试者,采用标准两周期交叉设计自身对照试验法,单剂量口服进口和国产格列吡嗪片10mg,以高效液相色谱法测定血浆中格列吡嗪的经时浓度,以双单侧t检验统计法比较两种格列吡嗪片之间的差异.结果两种格列吡嗪片在健康志愿者体内的药-时曲线均符合一级吸收的单室模型,国产格列吡嗪片主要的药动学参数Tmax、Cmax和AUC(0-17)分别为(2.6±0.5)h,(609.7±112.9)ng·ml-1和(4499.8±969.0)ng·h-1·ml-1;进口格列吡嗪片主要的药动学参数Tmax、Cmax和AUC(0-17)分别为(2.6±0.5)h,(568.8±101.9)ng·ml-1和(4108.3±724.9)ng·h·     

阿奇霉素片在健康人体的相对生物利用度和药代动力学

目的研究阿奇霉素片（大环内酯类抗生素）在健康人体的相对生物利用度及药代动力学。方法19名健康受试者自身交叉单剂量口服阿奇霉素片受试制剂和参比药物各500mg后，用微生物法测定用药后不同时间血药浓度。结果2制剂的血药浓度-时间曲线基本一致，符合二房室模型，受试制剂和参比药物的药代动力学参数：t1/2β分别为（34．61±7．42），（31．16±5．28）h；tmax分别为（2．60±0．21），（2．55±0．16）h；Cmax分别为（557．15±129．57），（548．34±137．46）μg·L^-1；AUC0-tn分别为（8．45±2．29），（8．66±2．34）h·mg·L^-1；受试制剂的相对生物利用度为（99．35±19．77）％。结论受试制剂与参比药物生物等效。     

国产舒他西林片在健康人体内的药动学及相对生物利用度

目的在8名健康志愿者体内研究了国产舒他西林片和对照片的药动学和生物利用度。方法受试者交叉口服单剂量(750mg)国产片和进口片后,采用高效液相色谱法检测血药浓度。结果国产片和对照片中两种成分的主要药动学参数分别为舒巴克坦C     

西沙必利片剂和胶囊剂人体药代动力学及相对生物利用度研究

目的研究西沙必利片剂及胶囊剂在健康人体内的药代动力学及相对生物利用度。方法采用反相高效液相色谱法测定12名健康自愿者单剂量口服三种制剂各15mg后,血浆中西沙必利浓度变化情况,用3P97程序按非室模型进行药代动力学分析。结果测得主要药代动力学参数为试验片剂T     

Single dose pharmacokinetics and bioavailability of nevirapine in healthy volunteers

The results of two randomized, single-dose, crossover bioavailability studies are presented which describe the pharmacokinetics and oral bioavailability of nevirapine, a novel nonnucleoside antiretroviral drug. In the first study 12 healthy male volunteers received nevirapine 15 mg via short-term i.v. infusion or orally as a 50 mg tablet or reference solution (50 mg/200 mL). Following the i.v. dose, nevirapine had a low systemic clearance (Mean +/- S.D., Cl = 1.4 +/- 0.3 L/h) and a prolonged elimination phase (t(1/2beta) = 52.8 +/- 14.8 h; MRT = 81.4 +/- 22.4 h). Nevirapine absolute bioavailability was 93 +/- 9% and 91 +/- 8% for the tablet and oral solution, respectively. In the second study, 24 healthy male volunteers were administered nevirapine as a 200 mg production-line tablet or oral reference solution (200 mg/200 mL). There was no significant difference in bioavailability between the tablet and reference solution. Overall, comparison of the pharmacokinetic parameters between the 50 and 200 mg doses indicates that nevirapine is well absorbed at clinically relevant doses. The absorption profiles using deconvolution revealed no evidence of differential enzyme induction between the two doses or routes of administration following a single dose.     

国产格列美脲片在人体内的药动学及相对生物利用度

目的 :在 10名健康志愿者体内研究了国产格列美脲片和进口对照片的药动学和生物利用度。方法 :受试者交叉自身对照分别口服单剂量受试片或参比片各 4mg,采用高效液相色谱法检测血药浓度。结果 :国产片和对照片主要药动学参数 :Cmax分别为 (4 15 .6± 10 7.3)和 (4 0 6 .3± 15 0 .1) μg·L-1;Tmax分别为 (3.1± 0 .5 )和 (3.2± 0 .7)h ;T1/2 分别为 (7.3± 1.5 )和 (7.5± 1.7)h;AUC0→t分别为 (2 4 39.8± 5 98.5 )和 (2 2 2 6 .1± 4 5 8.9) μg·L-1·h ;AUC0→∞ 分别为 (2 6 35 .4± 6 5 5 .8)和 (2 4 0 2 .4± 4 6 3.9) μg·L-1·h。受试片与参比片比较 ,生物利用度F为 (110 .8± 18.1) %。结论 :统计学结果显示 ,两制剂具有生物等效性。