国产与进口盐酸西替利嗪的生物利用度测定

目的：比较国产与进口盐酸西替利嗪片剂在健康成年男性志愿者体内的药代动力学和生物利用度.方法：12例健康志愿者采用2周期随机交叉设计自身对照试验法,口服进口或国产盐酸西替利嗪片各10 mg,以反相高效液相色谱法测定血浆中药物浓度.结果：国产西替利嗪与进口西替利嗪的主要药物动力学参数为：Cmax分别为(429.00±108.80)和(469.82±113.83) ng·mL 1,Tmax分别为(0.90±0.51)和(0.91±0.40) h,以梯形法计算AUC0～36分别为(3 312.72±682.39)和(3 417.11±517.42) ng·h·mL 1.国产西替利嗪相对生物利用度(97.21±13.32)%.主要药物动力学参数经方差分析和双单侧t检验证明差异无显著性(P＞0.05).结论：国产西替利嗪与进口西替利嗪在受试者体内的药代动力学参数相似,具有生物等效性.［关键词］西替利嗪,盐酸;生物利用度;反相高效液相色谱法     

奥美拉唑肠溶片生物利用度测定

目的　考察奥美拉唑肠溶片人体相对生物利用度及生物等效性。方法　 10名健康男性志愿者 ,采用交叉给药方案 ,分别单剂量po 2 0mg国产奥美拉唑肠溶片和进口奥美拉唑胶囊 ,用高效液相色谱紫外检测法测定血浆中奥美拉唑浓度 ,进行人体相对生物利用度和生物等效性评价。结果　单次po 2 0mg国产奥美拉唑肠溶片和进口奥美拉唑胶囊后 ,达峰时间tmax分别为 3 0 1± 0 5 2h和 2 6 2± 0 76h ;峰值血药浓度Cmax分别为 5 4 3 5± 2 14 9ng·ml-1和 5 2 0 9± 16 7 8ng·ml-1;药时曲线下面积AUC0→∞ 分别为 10 2 3 0± 5 4 2 5h·ng·ml-1和 10 71 2± 5 73 8h·ng·ml-1。结论　国产奥美拉唑肠溶片的相对生物利用度为96 4 0 % ,主要参数的双单侧t检验 ,结果显示两种制剂为生物等效制剂。     

Rectal absorption of lamotrigine compressed tablets

PURPOSE: Interruption of oral drug administration poses a significant clinical problem for antiepileptic drugs that have no parenteral formulation. If a drug is absorbed rectally, rectal administration can be a useful alternative when the oral route of administration is not possible. The purpose of this study was to compare the single-dose pharmacokinetics of lamotrigine (LTG) compressed tablets after rectal and oral administration in healthy volunteers. METHODS: A single LTG compressed tablet (100 mg) was administered orally and rectally to 12 volunteers in this single-dose, two-period, crossover study with a 2-week washout between doses. For rectal administration, tablets were crushed and suspended in 10 mL of water. Plasma samples were collected from 0 to 120 hr after each dose and analyzed for LTG by an HPLC method developed for this investigation. RESULTS: LTG plasma concentrations were lower after rectal administration versus oral administration. The average area under the curve was 28.90 +/- 9.5 microg/mL/hr after rectal administration and 51.71 +/- 19.2 microg/mL/hr after oral administration. The average maximum LTG concentration was 0.53 +/- 0.14 microg/mL after rectal administration and 1.45 +/- 0.35 microg/mL after oral administration. The relative bioavailability for LTG compressed tablets was 0.63 +/- 0.33 for rectal administration. There were no drug-related rashes or serious side effects. CONCLUSIONS: LTG suspension prepared from LTG compressed tablets is absorbed rectally, although not to the same extent or rate as when given orally.     

Mechanisms governing the differentiation of a serotonergic phenotype in culture

The blood–brain barrier prevents the entry of many potentially therapeutic peptide drugs to the brain. Glycosylation has shown potential as a methodology for improving delivery to the CNS. Previous studies have shown improved bioavailability and improved centrally mediated analgesia of glycosylated opioids. In this study we investigate the effect of glycosylation on the cyclic opioid peptide [ -Cys^2,5,Ser⁶,Gly⁷] enkephalin. The peptide was glycosylated on the Ser⁶ via an O-linkage with various sugar moieties and alignments. The peptides were then investigated for receptor binding, physiochemical attributes, in situ brain uptake in female Sprague–Dawley rats and antinociception in male ICR mice. Glycosylation resulted in a slight decrease in affinity to the δ-opioid receptor, and mixed effect on binding to the μ-opioid receptor. There was a significant decrease in lipophilicity resulting from glycosylation and a slight reduction in binding to bovine serum albumin. In situ perfusion showed that brain uptake was improved by up to 98% for several of the glycosylated peptides, and the nociceptive profiles of the peptides, in general, followed the rank order of peptide entry to the brain with up to a 39-fold increase in A.U.C.     

格列吡嗪胶囊的相对生物利用度和生物等效性

目的:考察格列吡嗪胶囊人体相对生物利用度及生物等效性。方法:20名健康男性志愿者,采用交叉给药方案,分别单剂量口服5.0mg受试格列吡嗪胶囊和参比格列吡嗪胶囊,用液相色谱-串联质谱法测定血浆中格列吡嗪浓度,进行人体相对生物利用度和生物等效性评价。结果:单次口服5.0mg受试格列吡嗪胶囊和参比格列吡嗪胶囊后,达峰时间(Tmax)分别为(2.1±0.5)h和(2.2±1.1)h;峰值血药浓度(Cmax)分别为(298.95±105.66)ng/ml和±281.55±68.84)ng/ml;半衰期(t1/2)分别为(4.14±1.33)h和(3.80±1.28)h;药时曲线下面积采用梯形法计算,AUC0-t分别为(1565.89±659.41)ng·h/ml和(1580.13±465.43)ng·h/ml,AUC0-∞分别为(1649.53±704.58)ng·h/ml和(1644.15±478.92)ng·h/ml。结论:受试格列吡嗪胶囊的相对生物利用度为(98.3±19.3)%,主要参数的双、单侧t检验,结果显示两种制剂为生物等效制剂。     

HIV-1蛋白酶抑制剂前药的研究进展

综述HIV1蛋白酶抑制剂前药的研究进展。HIV1蛋白酶抑制剂前药是以HIV1蛋白酶抑制剂为母体,通过引入亲脂性或亲水性基团等结构修饰而得到的一类药物前体,尤其是基于蛋白酶抑制剂和逆转录酶抑制剂为母体药物设计的“双药”型抗HIV1前药,它们能在体内水解释放出母体药物,从而提高母体药物活性及生物利用度,降低其耐药性或交叉耐药性。     

双氯芬酸钾胶囊的人体生物等效性研究

目的:研究2种双氯芬酸钾胶囊的人体生物等效性。方法:20名健康男性志愿者随机交叉单剂量口服受试制剂或参比制剂,采用高效液相色谱-质谱法测定血药浓度,计算药动学参数和相对生物利用度。结果:受试制剂与参比制剂的药-时曲线符合一房室模型,AUC0～8分别为(2.27±0.66)、(2.16±0.58)(μg·h)/ml,Cmax分别为(1.27±0.40)、(1.38±0.58)μg/ml,tmax分别为(0.9±0.7)、(1.0±0.7)h;受试制剂的相对生物利用度为(104.9±12.8)%。结论:2种双氯芬酸钾胶囊具有生物等效性。     

Effects of Fluvastatin on the Pharmacokinetics of Repaglinide: Possible Role of CYP3A4 and P-glycoprotein Inhibition by Fluvastatin

The purpose of this study was to investigate the effects of fluvastatin on the pharmacokinetics of repaglinide in rats. The effect of fluvastatin on P-glycoprotein and CYP3A4 activity was evaluated. The pharmacokinetic parameters and blood glucose concentrations were also determined after oral and intravenous administration of repaglinide to rats in the presence and absence of fluvastatin. Fluvastatin inhibited CYP3A4 activity in a concentration-dependent manner with a 50% inhibition concentration(IC₅₀) of 4.1 µM and P-gp activity. Compared to the oral control group, fluvastatin significantly increased the AUC and the peak plasma level of repaglinide by 45.9% and 22.7%, respectively. Fluvastatin significantly decreased the total body clearance (TBC) of repaglinide compared to the control. Fluvastatin also significantly increased the absolute bioavailability (BA) of repaglinide by 46.1% compared to the control group. Moreover, the relative BA of repaglinide was 1.14- to 1.46-fold greater than that of the control. Compared to the i.v. control, fluvastatin significantly increased the AUC_0-∞ of i.v. administered repaglinide. The blood glucose concentrations showed significant differences compared to the oral controls. Fluvastatin enhanced the oral BA of repaglinide, which may be mainly attributable to the inhibition of the CYP3A4-mediated metabolism of repaglinide in the small intestine and/or liver, to the inhibition of the P-gp efflux transporter in the small intestine and/or to the reduction of TBC of repaglinide by fluvastatin. The study has raised the awareness of potential interactions during concomitant use of repaglinide with fluvastatin. Therefore, the concurrent use of repaglinide and fluvastatin may require close monitoring for potential drug interactions.     

Pharmacokinetics,biocompatibility and bioavailability of a controlled release monoclonal antibody formulation

The sustained and localized delivery of monoclonal antibodies has become highly relevant, because of the increasing number of investigated local delivery applications in recent years. As the local delivery of antibodies is associated with high technological hurdles, very few successful approaches have been reported in the literature so far. Alginate-based delivery systems were previously described as promising sustained release formulations for monoclonal antibodies (mAbs). In order to further investigate their applicability, a single-dose animal study was conducted to compare the biocompatibility, the pharmacokinetics and the bioavailability of a human monoclonal antibody liquid formulation with two alginate-based sustained delivery systems after subcutaneous administration in rats. 28 days after injection, the depot systems were still found in the subcutis of the animals. A calcium cross-linked alginate formulation, which was injected as a hydrogel, was present as multiple compartments separated by subcutaneous tissue. An in situ forming alginate formulation was recovered as a single compact and cohesive structure. It can be assumed that the multiple compartments of the hydrogel formulation led to almost identical pharmacokinetic profiles for all tested animals, whereas the compact nature of the in situ forming system resulted in large interindividual variations in pharmacokinetics. As compared to the liquid formulation the hydrogel formulations led to lower mAb serum levels, and the in situ forming system to a shift in the time to reach the maximum mAb serum concentration (T_max) from 2 to 4 days. Importantly, it was shown that after 28 days only marginal amounts of residual mAb were present in the alginate matrix and in the tissue at the injection site indicating nearly complete release. In line with this finding, systemic drug bioavailability was not affected by using the controlled release systems. This study successfully demonstrates the suitability and underlines the potential of polyanionic systems for local and controlled mAb delivery.