阿德福韦酯自乳化制剂大鼠体内药动学的初步研究

目的：研究阿德福韦酯自乳化制剂在大鼠体内的药动学过程。方法：以随机分组组间对照实验设计方法,通过高效液相色谱法测定6只SD大鼠（两组）体内单剂量灌胃服用阿德福韦酯自乳化制剂和片剂100mg／kg后不同时间点的血药浓度,并计算其药动学参数。结果：自乳化制剂组大鼠的Cmax为2．5094μg／mL,AUC为277．2911μg·min／mL）;片剂组大鼠的Cmax为1．7258μg／mL,AUC为215．9196μg·min／mL）。结论：阿德福韦酯自乳化制剂的口服生物利用度优于片剂。     

氟比洛芬微乳大鼠药动学研究

目的评价自制氟比洛芬微乳在大鼠体内的药动学和相对生物利用度。方法两组SD雄性大鼠分别单剂量给予氟比洛芬微乳和氟比洛芬片,采用HPLC测定血药浓度。应用3P87药动学程序对数据进行处理计算药动学参数。结果单剂量给药后氟比洛芬微乳和氟比洛芬片的主要药动学参数Cmax分别为(4976.1±500.9)ng·mL-1和(3684.0±500.6)ng·mL-1,tmax分别为(1.17±0.37)h和(2.33±0.46)h,AUC0→36分别为(44613.5±8515.7)ng·mL-1和(34126.5±7909.6)ng·h·mL-1,相对生物利用度为130.46%。结论以市售氟比洛芬片为参比制剂,氟比洛芬微乳在大鼠体内的生物利用度明显提高。     

姜黄素固体脂质纳米粒在大鼠体内的药动学

目的:研究姜黄素固体脂质纳米粒在SD大鼠体内的口服药动学情况。方法:大鼠单剂量灌胃给予姜黄素固体脂质纳米粒和游离药姜黄素,眼底静脉丛取血,以醋酸乙酯处理血浆样品,尼群地平为内标,高效液相法(HPLC)测定血浆中姜黄素的含量,并用药物与统计(Drug and Statistics,DAS)软件分析处理药动学数据。结果:姜黄素固体脂质纳米粒和游离药姜黄素在大鼠体内的药动学行为均符合二室开放模型,姜黄素固体脂质纳米粒和游离药姜黄素的药动学参数分别如下:药时曲线下面积(AUC0-t)为(798.00±64.44)μg·h·L-1和(108.78±14.22)μg·h·L-1,药时曲线下总面积(AUC0-∞)为(939.49±114.18)μg·h·L-1和(126.99±28.14)μg·h·L-1,峰浓度(Cmax)为(93.84±5.66)μg·L-1和(72.46±2.66)μg·L-1,消除半衰期(t1/2)为(17.16±1.61)h和(4.71±1.18)h,姜黄素固体脂质纳米粒的AUC0-t、AUC0-∞、Cmax和t1/2分别提高了7.34,7.40,1.30和3.64倍。结论:姜黄素固体脂质纳米粒体内消除慢,血药浓度高,且明显提高了姜黄素的口服生物利用度。     

姜黄素纳米制剂抗消化系统肿瘤的药理作用研究进展

姜黄素（curcumin）是从姜黄中提取的多酚化合物,具有抗肿瘤、抗炎、抗菌等广泛的药理活性,但其溶解度低、生物利用度差、药动学差,限制了该药的临床应用。近年来,基于纳米技术的药物递送系统（主要包括纳米颗粒、脂质体、胶束、聚合物、纳米凝胶等）有效改善了姜黄素的生物利用度和溶解性,提高了体内药物活性。就姜黄素纳米制剂在消化系统肿瘤（胃癌、肝癌、结直肠癌、胰腺癌和食管癌）中的应用进行综述,旨在为姜黄素纳米制剂的进一步研究与利用提供参考。     

姜黄素纳米乳的体内外药动学研究

目的 研究姜黄素纳米乳的体内外药动学,并与游离的药物比较.方法 用透析法考察姜黄素纳米乳体外释放药物的特点,建立大鼠模型研究其在体内的吸收情况.结果 姜黄素纳米乳和游离姜黄素在0.1 mol·L-1盐酸和pH6.8磷酸缓冲溶液中的释药符合Higuchi模型,纳米乳的释放曲线在各种释放介质中与游离药物的相似因子均小于50;而姜黄素纳米乳的Ka和Papp在不同肠段与游离药物的相比均提高了约2倍,AUC(0-72)约是游离药物的4倍.结论 姜黄素纳米乳较游离药物提高了药物的生物利用度.     

依托泊苷固体自微乳的研制及大鼠体内生物利用度研究

目的:制备依托泊苷固体自微乳制剂(SSMEDDS)并研究大鼠灌胃后的药动学行为,提高依托泊苷口服生物利用度.方法:通过相图法得到相应的自乳化区域,并以自乳化速率、粒径及溶解度等作为考察指标筛选处方,寻找出最佳处方配比;采用溶出度实验测定依托泊苷固体自微乳的体外溶出度等理化参数;考察了依托泊苷固体自微乳制剂、市售制剂和原料药混悬液经大鼠灌胃给药后的药动学行为.结果:依托泊苷自微乳的平均粒径为(21.8±1.5)nm,且固体自微乳制剂45 min溶出95％以上,同时药动学数据显示依托泊苷固体自微乳、原料药和市售制剂的AUC分别为12.20、8.25、10.49 mg·h·L-1.结论:VP-16制成固体自微乳制剂后的AUC略高于市售制剂,且大大提高了依托泊苷原料药的生物利用度.     

联苯双酯固体脂质纳米粒注射给药在大鼠体内的药动学

目的:研究联苯双酯固体脂质纳米粒在大鼠体内的药动学。方法:制备联苯双酯固体脂质纳米粒,大鼠尾静脉注射给药,高效液相色谱法测定不同时间血浆中联苯双酯的浓度,通过3P97程序计算药动学参数。结果:药动学研究表明联苯双酯固体脂质纳米粒消除较慢,生物利用度较高,无论是药物溶液还是纳米混悬液,在大鼠体内的药动学过程均符合二室模型。结论:与药物溶液相比,联苯双酯固体脂质纳米粒具有明显的缓释效果,同时还能提高药物的生物利用度。     

磷酸川芎嗪滴丸和片剂在健康人体内的生物等效性研究

目的:比较磷酸川芎嗪滴丸剂与片剂在健康人体内的生物等效性。方法:20名健康志愿者采用双周期交叉试验,单剂量口服受试制剂(滴丸剂)与参比制剂(片剂)各200 mg,采用HPLC法测定血清中的药物浓度,并用DAS 2.0药动学程序计算其药动学参数和相对生物利用度。结果:两者的体内过程均符合一室房室模型,受试制剂和参比制剂的主要药动学参数分别为:t1/2(71.47±18.43)和(63.57±27.38)min,cmax(1.73±0.30)和(1.61±0.35)μg/mL,tmax(40.50±15.47)和(67.75±31.93)min,AUC0～300(173.49±39.64)和(160.48±52.85)μg.min.mL-1。受试制剂的相对生物利用度为(115.1±35.4)%。结论:磷酸川芎嗪滴丸剂和片剂具有生物等效性。     

姜黄素纳米混悬液的制备及体内药动学

目的 优化处方工艺,制备稳定的姜黄素纳米晶混悬液,以提高溶出和生物利用度.方法 通过Box-Behnken设计优化姜黄素纳米晶混悬液的处方工艺,并监测粒度和电位的稳定性,通过差示扫描量热分析(DSC)和X射线粉末衍射分析(XRPD)考察研磨前后晶型变化,并通过体外溶出和大鼠体内药动学评价该制剂的体内外释放特征.结果 最...     

帕罗西汀片在健康人体的药动学与生物等效性

［摘要］目的研究帕罗西汀片剂在健康人体的药动学过程，并比较两种帕罗西汀片剂的生物等效性。方法男性健康志愿者20例，随机交叉单剂量口服帕罗西汀片试验制剂和参比制剂40 mg后，用高效液相色谱法测定血浆帕罗西汀浓度。并用3P97药动学软件进行参数计算及评价两种制剂的生物利用度和生物等效性。结果单剂量口服试验制剂和参比制剂后血浆帕罗西汀的主要药动学参数如下：Cmax分别为（62.78±17.34）和（64.74±18.43） ng·mL 1；tmax 分别为（5.13±1.37） 和（5.64±1.84） h；t1/2分别为（19.85±5.72） 和（20.03±5.33） h；AUC0 120分别为（1 043.21±297.33）和（1 076.47±309.49） ng·h·mL 1；AUC0－inf分别为（1 358.35±443.73）和（1 386.75±476.54） ng·h·mL 1。试验制剂与参比制剂的人体相对生物利用度为F0 120（98.9±16.3）%,F0 inf（96.3±18.2）%。结论两种帕罗西汀片剂具有生物等效性。     

Improved Lipid Lowering Activity of Bezafibrate Following Continuous Gastrointestinal Administration: Pharmacodynamic Rationale for Sustained Release Preparation of the Drug

Purpose. To evaluate the role of different routes and modes of administration of bezafibrate (BZF) on its hypolipidemic activity. We hypothesize that the major sites of BZF action are located presystemically as in other 'gastrointestinal (GI) drugs.' Thus, continuous administration of the drug to the GI tract is expected to augment its efficacy and provides a rationale for an oral sustained release preparation of the drug. Methods. The hypothesis was investigated in three experimentally induced-hyperlipidemia rat models. Models A and B were based on cholesterol-enriched diets and Model C on induced acute hyperlipidemia by triton 225 mg/kg. The pharmacokinetics and the pharmacodynamics of the drug following various modes of administration were examined. Results. In all cases, continuous administration of the drug into the duodenum (IGI) at a dose of 30 mg/kg/day for 3 days (Models A and B) or over 18 hr (Model C) reduced significantly both total cholesterol and triglycerides levels and elevated HDL cholesterol levels in comparison to bolus oral administration of the same dose, as well as in comparison to equivalent intravenous infusion (Model C). Infusion of the drug directly into the portal vein produced an equivalent activity to IGI administration. The pharmacokinetic study showed 100% oral bioavailability, good colonic absorption properties and an indication for an enterohepatic cycle. Conclusions. The results confirm that BZF has a first pass hepatic pharmacodynamic effect. Administration of BZF in a slow release matrix tablet to the rats produced the same magnitude of effect as IGI administration, thus proving the pharmacodynamic rationale for this mode of administration for GI drugs.     

姜黄素-PLGA纳米粒提高口服给药生物利用度的研究

目的 研究乳酸/羟基乙酸共聚物（PLGA）纳米粒子提高姜黄素口服生物利用度。方法 采用乳液挥发法制备姜黄素-PLGA纳米粒;通过透射电镜（transmission electron microscope,TEM）观察纳米粒形态;采用动态光散射法（dynamic light scattering,DLS）测定纳米粒大小、表面电位（Zeta电位）;考察药物的体外稳定性以及药物释放行为;以大鼠口服灌胃给药方式考察姜黄素和姜黄素-PLGA纳米粒的体内药物生物利用度。结果 姜黄素-PLGA纳米粒粒度分布均匀,平均粒径大小约200 nm;姜黄素-PLGA纳米粒具有较高的载药量和包封率以及稳定性,体外药物释放实验结果显示具有一定的缓释效果;口服灌胃100 mg·kg^-1姜黄素和姜黄素-PLGA纳米粒,给药30 min之后,姜黄素-PLGA纳米粒给药组的血药浓度水平显著高于姜黄素组（P〈0.05）,药物生物利用度提高到原来的5.2倍。结论 姜黄素-PLGA纳米粒可以有效的提高姜黄素稳定性和口服给药生物利用度。     

阿昔洛韦复乳的研究:大鼠吸收动力学、生物利用度和趋肝性

目的:研究阿昔洛韦(ACV) 复乳的口服生物利用度和肝靶向性。方法:采用高效液相色谱法测定大鼠口服ACV 复乳和普通片剂后的血药浓度和肝组织分布,对试验数据进行药动学分析。药物浓度对时间数据作房室模型和统计矩解析,并求出相应的药动学参数。结果:大鼠口服ACV 复乳对片剂的相对生物利用度为149-8 % ,达峰时间和血浓维持时间明显延迟。血浓经时过程符合二室开放线性药动学模型。血浓峰值附近的肝组织药物分布是片剂的1-62 倍(P<0.1) ,谷值附近是片剂的5-16 倍(P<0.05) 。结论:大鼠口服ACV 复乳可提高生物利用度,并有一定的肝靶向性。     

Pharmacokinetics and pharmacodynamics of bumetanide after intravenous and oral administration to spontaneously hypertensive rats and DOCA-salt induced hypertensive rats

The pharmacokinetics and pharmacodynamics of bumetanide were investigated after intravenous (i.v.) administration, 10 mg kg^?1, and oral administration, 20 mg kg^?1, to spontaneously hypertensive rats (SHRs) and deoxycorticosterone acetate-salt induced hypertensive rats (DOCA-salt rats). After i.v. administration, the pharmacokinetic and pharmacodynamic parameters of bumetanide did not vary significantly between SHRs and the control Wistar rats. Similar results were also shown between DOCA-salt rats and the control Sprague-Dawley (SD) rats. After oral administration, the AUC_{0–12 h} decreased significantly (186 versus 335 μg min ml^?1) in SHRs and this resulted in decreased F(15.4 versus 23.6 and 2.78 versus 5.76% using two equations) in SHRs when compared with the control Wistar rats, although none of the other pharmacokinetic parameters varied significantly between SHRs and Wistar rats. This effect seemed to be due to the decreased enterohepatic recirculation of bumetanide in SHRs: the amounts of both bumetanide and its glucuronide product, which are capable of enterohepatic recirculation, excreted in 8 h bile juice decreased significantly in SHRs (11.3 versus 37.4 μg as expressed in terms of bumetanide) when compared with Wistar rats. The pharmacodynamic parameters did not vary significantly between SHRs and Wistar rats after oral administration of bumetanide. The pharmacokinetic and pharmacodynamic parameters of bumetanide did not vary significantly between DOCA-salt rats and SD rats after oral administration of the drug. The liver weights compared to body weight increased significantly in SHRs when compared with Wistar rats and the corresponding values for the kidney increased significantly in DOCA-salt rats when compared with SD rats.     

Mucoadhesive bilayer buccal tablet of carvedilol-loaded chitosan microspheres: in vitro,pharmacokinetic and pharmacodynamic investigations

A multiple-unit system comprising mucoadhesive bilayer buccal tablets of carvedilol-loaded chitosan microspheres (CMs) was developed to improve bioavailability and therapeutic efficacy of carvedilol. Drug-loaded CMs were prepared by spray drying, evaluated for powder and particle characteristics, and optimized batch of CMs was compressed into bilayer buccal tablets using Carbopol. Tablets were evaluated for physicochemical parameters, in vitro drug release, in vivo pharmacokinetic and pharmacodynamic studies. Optimized formulation, CMT1 (CMT, chitosan microsphere tablet) showed maximum mucoadhesive force (50?±?1.84?dyne/cm²), exhibited 73.08?±?3.05% drug release and demonstrated zero-order kinetics with non-Fickian release mechanism. Pharmacokinetic studies in rabbits showed significantly higher C_max (71.26?±?6.45?ng/mL), AUC_0–10 (AUC, area under the curve 390.75?±?5.23?ng/mL/h) and AUC_0–∞ (664.72?ng/mL/h) than carvedilol oral tablet. Pharmacodynamic studies confirmed reduction in mean arterial pressure, heart rate, body weight and triglyceride on administration of bilayer buccal tablet compared to oral carvedilol tablet. Multiple-unit system exhibited enhanced bioavailability and sustained release of carvedilol, indicating its improved therapeutic potential for the treatment of hypertension.     

Comparative single-dose pharmacokinetics of rasagiline in minipigs after oral dosing or transdermal administration via a newly developed patch

Abstract

1. A rasagiline transdermal patch was developed for the treatment of early and advanced Parkinson’s disease. Relevant pharmacokinetic parameters of rasagiline obtained after transdermal administration to minipigs were compared with those of rasagiline after oral administration.

2. A total of 18 minipigs were randomly divided into three groups (six animals for each group). A single dose of 1?mg rasagiline tablet was orally administrated to one group. Meanwhile, single dose of 1.25 and 2.5?mg (2 and 4?cm²) rasagiline patches were given (at the postauricular skin) to the other two groups, respectively. The pharmacokinetic parameters such as plasma half-life (t_1/2), time to peak plasma-concentration (T_max), mean residence time (MRT), area under the curve (AUC_(0–t)) were significantly (p?<?0.05) different between transdermal and oral administrations.

3. The plasma half-life (t_1/2) of rasagiline (1.25?mg patch: 11.8?±?6.5?h, 2.5?mg patch: 12.5?±?4.7?h) in minipig following transdermal administration was significantly prolonged as compared with that following the oral administration (1?mg tablet: 4.7?±?2.5?h). The dose-normalized relative bioavailability of rasagiline patch in minipig were 178.5% and 156.4%, respectively, for 1.25 and 2.5?mg patches compared with 1?mg rasagiline tablet. The prolonged t_1/2 and increased bioavailability of rasagiline patch suggested a possible longer dosing interval compared with oral tablet.     

Effects of oral curcumin on the pharmacokinetics of intravenous and oral etoposide in rats: possible role of intestinal CYP3A and P-gp inhibition by curcumin

This study aimed to investigate the effects of oral curcumin on the pharmacokinetics of intravenous and oral etoposide in rats. Intravenous (6 mg/kg) or oral (2 mg/kg) etoposide was administered to rats in the absence and the presence of oral curcumin (0.4, 2 or 8 mg/kg). The effects of curcumin on the P‐glycoprotein (P‐gp) and CYP3A4 activity was also evaluated. Curcumin inhibited CYP3A4 enzyme activity with a 50% inhibition concentration (IC₅₀) of 2.7 µM . In addition, curcumin (10 µm) significantly enhanced the cellular accumulation of rhodamine‐123 in MCF‐7/ADR cells overexpressing P‐gp. Compared with the control group (given etoposide alone), curcumin (2 or 8 mg/kg) increased significantly the oral bioavailability (AUC and C_max) of etoposide. Consequently, the extent of absolute oral bioavailability (F) of etoposide with curcumin was significantly enhanced compared with that in the control group. In contrast, curcumin did not affect the pharmacokinetics of etoposide after intravenous administration. Therefore, the enhanced oral bioavailability of etoposide in the presence of curcumin might be due mainly to inhibition of the P‐gp efflux pump in the small intestine and possibly by reduced first‐pass metabolism of etoposide in the small intestine by inhibition of CYP3A activity in rats. The combined use of curcumin may be helpful to improve the F of etoposide in chemotherapeutic applications. Copyright © 2011 John Wiley & Sons, Ltd.     

Biocompatibility,absorption and safety of protein nanoparticle-based delivery of doxorubicin through oral administration in rats

Abstract

Doxorubicin, a potent anticancer drug associated with cardiotoxicity and low oral bioavailability, was loaded into apotransferrin nanoparticles to improve its pharmacological performance. Here, doxorubicin (doxo)-loaded apotransferrin nanoparticles were termed as Apodoxonano, and they were prepared by sol-oil chemistry. The pH-dependent stability of nanoparticles in simulated fluids was evaluated, and the in vitro release was investigated in phosphate-buffered saline. The pharmacokinetic and toxicity studies were conducted in Wistar rats. Nanoparticles have an average size of 75?nm, with 63% entrapment efficiency, at 10?mg w/w of apotransferrin. The particles displayed good pH-dependent stability in the pH range 1.1–7.4, but sensitive at endosomal pH of 5.5, thus facilitating intracellular drug release in endosomes. Multiplex assay showed high transport ability of nano form across epithelial cells (caco-2) when compared to doxo. Moreover, during oral administration, Apodoxonano localizes significantly in esophagus, stomach and small intestine, suggesting that it was absorbed in GI tract through epithelial lining. The drug localization was shown to be significantly lower in the heart reflecting its decreased cardiotoxic nature. The Apodoxonano with a longer bioavailability and a negligible cardiotoxicity can serve as an effective and safe vehicle of drug delivery.     

Buccal Absorption of Testosterone and Its Esters Using a Bioadhesive Tablet in Dogs

Purpose. As the oral bioavailability of testosterone is very low because of its high first pass effect, buccal administration might present a viable alternative. In this study a buccal bioadhesive tablet was used in order to sustain the delivery and bypass the liver. Methods. Testosterone and testosterone acetate, propionate, enanthate and decanoate were investigated. The influence of the concentration of testosterone (10–50%) and testosterone esters (30%) on in vitro bioadhesion was investigated. The absolute (IV) and relative (oral) bioavailability of 60 mg testosterone or an equivalent amount of testosterone ester was determined in castrated male dogs. Results. Both the in vitro detachment force and the work of adhesion decreased gradually with an increasing amount of testosterone and for an increasing chain length of the esters, except in the case of testosterone enanthate. The in vivo results revealed that the bioavailability of testosterone was significantly higher (p < 0.05) than that of the esters, which is probably due to the lower solubility of the esters. The mean absolute bioavailability of testosterone from the bioadhesive tablet was 14.1%, while the mean relative bioavailability was 1370%. The buccal administration of testosterone via the bioadhesive tablet allowed the maintenance of the plasma level at above 3 ng/ml for 15 to 24 h. Conclusions. Buccal absorption of testosterone was significantly higher than that of its esters.     

Estimation of Oral Bioavailability of a Long Half-Life Drug in Healthy Subjects

Purpose. To estimate and compare the oral bioavailability of a drug (BMS-187745) administered as single doses of oral solution of either the parent drug or its prodrug (BMS-188494). Methods. A single-dose, two-period, three-treatment, control-balanced, residual-effect, incomplete block crossover study was completed in 16 healthy male subjects. All subjects received a 10 mg IV infusion of BMS-187745, and a single oral dose of either BMS-187745 (PO1) or BMS-188494 (PO2). A model is proposed to calculate the oral bioavailability of BMS-187745 which has a long half-life; incomplete data points were available to characterize its elimination phase. The plasma concentration-time data obtained following IV infusion of parent drug, and after administration of either PO1 or PO2 treatment were fitted simultaneously with systemic pharmacokinetic parameters shared by both the oral and IV routes of administration. Results. The best simultaneous fittings of the plasma concentration-time data were obtained by using a biexponential pharmacokinetic model with a first-order absorption rate constant. The mean bioavailability (F) values of BMS-187745 estimated by the proposed model were 26.5% and 2.6% when given as oral solution of its prodrug and as the parent drug. The coefficient of variation (CV) of these F values are reasonable, ranging from 38–40%. In contrast, F calculated by the model-independent AUC method exhibited high CV, ranging from 111–120%. Conclusions. The oral bioavailability values estimated by the proposed model were more reasonable compared to those calculated by the model-independent AUC method. The proposed approach may be useful for estimating bioavailability of long half-life drugs when incomplete data points are available to characterize their elimination phase.