甘草次酸差向异构体单独和联合给药后在大鼠体内的药动学研究

本文建立了大鼠血浆中甘草次酸差向异构体的高效液相测定方法, 用于研究甘草次酸差向异构体在单独与混合灌胃给药后大鼠的药物代谢动力学过程。本研究分别对大鼠灌胃给予甘草次酸α异构体、β异构体和两者的混合物, 于给药后不同时间点采集血样, 样品经液液萃取后, 用高效液相色谱法测定甘草次酸差向异构体的血药浓度。色谱柱为Kromasil C₁₈ (150 mm × 4.6 mm, 5 µm); 流动相为乙腈–4 mmol·L⁻¹醋酸铵水溶液 (46∶54, v/v); 流速为1.0 mL·min⁻¹; 检测波长为250 nm; 采用DAS 2.0软件计算药动学参数。结果显示, 大鼠单独给予单体后, α-甘草次酸的AUC_0−t为 (11.30 ± 1.53) μg·h·mL⁻¹, C_max为 (2.36 ± 0.58) μg·mL⁻¹; β-甘草次酸的AUC_0−t为 (9.79 ± 0.98) μg·h·mL⁻¹, C_max为 (2.09 ± 0.41) μg·mL⁻¹。两单体混合给药后, α-甘草次酸的AUC_0−t为 (13.04 ± 2.63) μg·h·mL⁻¹, C_max为 (2.72 ± 0.50) μg·mL⁻¹; β-甘草次酸的AUC_0−t为 (7.46 ± 1.77) μg·h·mL⁻¹, C_max为 (1.90 ± 0.31) μg·mL⁻¹。本研究所建立的高效液相色谱法专属性强、灵敏度高, 可用于甘草次酸差向异构体的体内药动学研究。α-甘草次酸与β-甘草次酸混合给药时, 主要药动学参数存在显著性差异 (P < 0.05); 单独给药时, α-甘草次酸与β-甘草次酸的主要药动学参数无显著性差异。对各差向异构体单独给药与混合给药时的主要药动学参数进一步进行统计分析, α-甘草次酸在两种给药方式时无显著性差异, 而β-甘草次酸的AUC_0−t与AUC_0−∞存在显著性差异。     

莫达非尼在小鼠体内的药动学-药效学联合研究

对莫达非尼 (modafinil, MOD) 在小鼠体内的药动学和药效学进行联合研究, 以阐明其关联性, 为临床合理用药提供依据。以莫达非尼120 mg·kg⁻¹对小鼠灌胃给药, 采集给药后不同时间点血浆样本, 用HPLC检测血浆药物浓度, 分析平均血药浓度经时变化并计算药动学参数。以小鼠自主活动计数为药效学指标, 观测MOD 120 mg·kg⁻¹灌胃给药后不同时间段内小鼠自主活动量 (计数) 的变化, 分析与血浆药物浓度变化的相关性。结果显示, MOD在小鼠体内药动学过程符合二室模型, t_1/2α, t_1/2β, t_max, C_max, AUC_0−∞分别为0.42 h, 3.10 h, 1.00 h, 41.34 mg·L⁻¹和142.22 mg·L⁻¹·h。MOD使小鼠自主活动明显增多, 持续约4 h, 且与血浆药物浓度呈同步变化, 二者间存在明显的相关性。     

P2Y受体介导大鼠胃体环行肌收缩反应的药理学特点

观察大鼠离体胃体环行肌和胃底环行肌不同的药理学特征，分析核苷及核苷酸类物质诱发胃体环行肌收缩反应的作用特点和受体机制。制备大鼠离体胃体环行肌和胃底环行肌标本，利用受体药理学技术观察药物诱发的收缩反应。在胃体环行肌KCl所致收缩反应与胃底环行肌无显著性差别；但是，CCh收缩胃体环行肌的EC₅₀值 [(0.45 ± 0.15) μmol·L⁻¹] 显著高于胃底环行肌 [(0.20 ± 0.09) μmol·L⁻¹, P < 0.01]。5-HT和His收缩两种标本的EC₅₀值无显著差异 (P > 0.05); 但是, 在胃体环行肌5-HT和His产生收缩反应的E_max值 [(0.81 ± 0.26) 和 (0.88 ± 0.27) g] 显著小于胃底环行肌 [(2.67 ± 0.61) 和 (1.90 ± 0.68) g, P < 0.01]。在预收缩胃体环行肌，ATP (0.1～3 000 μmol·L⁻¹) 诱发浓度依赖性收缩反应，未见舒张反应；在预收缩胃底环行肌标本，同浓度ATP诱发先舒张后收缩的双相反应，并呈浓度依赖性。ATP、UTP、ADP、2-MeSATP和α, β-MeATP浓度依赖性诱发大鼠胃体环行肌收缩反应，2-MeSATP的EC₅₀值为 (7.2 ± 5.2) nmol·L⁻¹比Ach [(3.47 ± 1.20) μmol·L⁻¹] 低500倍；各药物产生收缩反应的效价序列为：2-MeSATP>>ADP>ATP=UTP>α, β-MeATP>>腺苷。酚妥拉明、普萘洛尔、阿托品及河豚毒素不影响ATP和UTP诱发的胃体环行肌收缩反应。研究结果表明, 大鼠胃体环行肌的药理学特征明显不同于胃底环行肌; 核苷酸类物质通过某种特殊的P2Y受体介导胃体环行肌收缩反应，是调节胃体环行肌收缩功能的重要介质。
     

6β-纳曲醇单次和连续肌内注射给药在犬体内的药代动力学

研究6β-纳曲醇单次和连续肌内注射给药在犬体内的药代动力学。Beagle犬 (n = 4) 肌内注射6β-纳  曲醇0.2 mg·kg⁻¹, 每日1次, 连续7日。用反相高效液相-电化学检测法测定血浆6β-纳曲醇浓度。Beagle犬单次 (第一次) 及连续给药 (最后一次) 后的血药浓度经时变化过程均符合血管外给药一级吸收二室模型 (R² > 0.999), 药代动力学参数分别为t_1/2α (0.26 ± 0.23) 和 (0.19 ± 0.18) h, t_1/2β (4.77 ± 1.65) 和 (5.79 ± 1.50) h, C_max (81.65 ± 5.61) 和 (79.82 ± 10.5) ng·mL⁻¹, t_peak (0.27 ± 0.07) 和 (0.18 ± 0.08) h, CL_s (1.20 ± 0.06) 和 (1.12 ± 0.07) L·kg⁻¹·h⁻¹, V/F_c (1.94 ± 0.15) 和 (2.10 ± 0.27) L·kg⁻¹, AUC_0−t (166.82 ± 7.68) 和 (173.23 ± 9.49) ng·h·mL⁻¹。第一次和最后一次给药的药代动力学参数无显著性差异 (P > 0.05)。连续给药期间, 血药峰浓度和谷浓度的平均值分别为  (79.03 ± 10.3) 和 (1.50 ± 0.93) ng·mL⁻¹。结果显示, 6β-纳曲醇在犬体内的药物代谢过程符合一级吸收二室模型, 得到了相应的药代动力学参数; 连续给药对原形药物代谢过程基本无影响。     

HPLC-ESI-MS法测定人血浆中依普利酮的浓度及其药动学研究(英文)

建立测定人血浆中依普利酮浓度的HPLC-ESI-MS法。依普利酮血浆样品采用乙酸乙酯提取, 色谱柱为反相色谱C₁₈柱, 流动相为10 mmol^.L⁻¹醋酸铵水溶液-甲醇 (30:70, v/v)。质谱离子源为电喷雾离子化 (ESI) 源, 选择性离子检测方式检测; 血浆样品在2～4 000 ng^.mL⁻¹内线性良好, 定量下限为2 ng^.mL⁻¹。本文采用该方法对健康受试者的人体药代动力学进行研究, 3个单剂量 (25 mg、50 mg和100 mg) 口服给药后的药代动力学参数分别为t_1/2: (4.9 ± 2.1)、(4.7 ± 1.5)、(5.9 ± 1.2) h; AUC_0−∞: (4 402 ± 1 735)、(8 150 ± 2 509)、(13 783 ± 4 102) µg^.h^.L⁻¹; MRT: (6.2 ± 2.1)、(6.6 ± 1.3)、(7.2 ± 1.6) h; 多剂量口服给药50 mg后药代动力学参数为t_1/2: (6.1 ± 1.7) h; AUC_ss : (10 071 ± 4 220) µg^.h^.L⁻¹; MRT: (8.1 ± 2.3) h; DF: (3.2 ± 1.0)。     

噻吩诺啡在人、比格犬和大鼠肝微粒体中体外代谢比较

采用体外肝微粒体孵育体系, 研究噻吩诺啡在大鼠、比格犬和人肝微粒体中酶代谢动力学及代谢产物差异。通过对噻吩诺啡浓度、微粒体蛋白含量和孵育时间等条件的考察优化噻吩诺啡与肝微粒体的反应体系; 应用LC-MS/MS定量检测孵育体系中的噻吩诺啡及代谢产物, 分析比较噻吩诺啡在3种肝微粒体中代谢产物种类和生成量的差异, 计算并比较相应的动力学参数。噻吩诺啡在人肝微粒体中代谢转化最慢, 其相应的动力学参数K_m = (4.00 ± 0.59) µmol·L⁻¹、V_max = (0.21 ± 0.06) µmol·L⁻¹·min⁻¹、T_1/2 = (223 ± 6.10) min、CL_int = (117 ± 3.19) mL·min⁻¹·kg⁻¹; 比格犬和大鼠肝微粒体中相应的参数K_m、V_max、T_1/2和CL_int分别为 (3.57 ± 0.69) 和 (3.28 ± 0.50) µmol·L⁻¹、(0.18 ± 0.04) 和 (0.14 ± 0.04) µmol·L⁻¹·min⁻¹、(244 ± 1.21) 和 (70.7 ± 1.05) min、(213 ± 1.06) 和    (527 ± 7.79) mL·min⁻¹·kg⁻¹。在3个种属肝微粒体中均观察到噻吩诺啡的6个I相代谢产物, 但6个产物的相对生成百分比在不同种属肝微粒体中有一定差异。实验结果表明, 噻吩诺啡在体外人、比格犬和大鼠肝微粒体中主要的I相代谢途径相同, 但是代谢产物的生成量及噻吩诺啡的代谢动力学性质存在着一定的差异。     

补骨脂酚的体外抗肿瘤活性及其关键中间体的合成研究

以他莫西芬为阳性对照物, 考察了补骨脂酚的体外抗人乳腺癌细胞株生物活性。生物活性测试结果表明补骨脂酚在低剂量下即有抑制人乳腺癌细胞增殖作用, 它对人乳腺癌细胞T-47D及MDA-MB-231的IC₅₀分别为2.89×10⁻⁵ mol·L⁻¹及8.29×10⁻³ mol·L⁻¹。另一方面, 本文以Ireland-Claisen重排为关键步骤, 在合成补骨脂酚所需的关键中间体时, 改进了常规Claisen重排反应的条件及试剂, 避免了有毒试剂的使用。     

甘草次酸在人细胞色素CYP450中体外代谢研究(英)

甘草根是中医临床常用解毒草药, 其活性成分甘草次酸主要是通过肝脏代谢。本文研究了人肝微粒体以及人源性CYP450s对甘草次酸的体外代谢影响, 以及甘草次酸对几种CYP450酶活性的影响。实验结果表明, 甘草次酸体外主要代谢酶为CYP3A4。体外药代动力学参数K_m, V_max和CL_int分别为18.6 μmol·L⁻¹, 4.4 nmol·mg⁻¹(protein)·min⁻¹和0.237 mL·mg⁻¹(protein)·min⁻¹。体外抑制试验显示, 50 μmol·L⁻¹甘草次酸可以抑制CYP2C19、CYP2C9、CYP3A4酶的活性, 其抑制率可高达50%以上。     

复方天麻颗粒中天麻素在大鼠体内的药动学研究

为了研究麦冬、五味子与天麻配伍对大鼠体内天麻素药动学的影响, 分别给Wistar大鼠灌胃低、中、高剂量复方天麻颗粒提取物 (剂量分别相当于天麻素50、100和200 mg·kg⁻¹) 及天麻提取物 (剂量相当于天麻素100 mg·kg⁻¹), 于不同时间点采集大鼠血浆。血浆样品经甲醇-乙腈沉淀蛋白后, 用液相色谱法测定血浆中天麻素含量。各给药组天麻素平均血药浓度-时间数据用WinNonlin 5.2.1药动学软件进行动力学分析, 组间药动学参数用SPSS 17.0软件进行统计分析。结果表明, 低、中剂量复方组天麻素在大鼠体内符合一级吸收非房室模型, 高剂量复方组天麻素在大鼠体内符合零级吸收非房室模型。对比分析大鼠灌胃100 mg·kg⁻¹天麻素的复方天麻颗粒提取物和天麻提取物时的药动学参数, 复方组C_max显著变小 (P < 0.01)、MRT_0−∞显著延长 (P < 0.01), 表明麦冬、五味子与天麻配伍, 可延缓天麻素的吸收, 降低消除速率, 增加体内作用时间。     

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。     

Micronization and microencapsulation of felodipine by supercritical carbon dioxide

Felodipine (FLD) is a poorly water-soluble drug. To improve its dissolution rate, the rapid expansion of supercritical solutions (RESS) technique was used to prepare micronized FLD drug particles, which were encapsulated in poly-(ethylene glycol) 4000 (PEG 4000). The physical properties of the encapsulated drug particles were characterized by a variety of analytical methods, including optical light microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (powder-XRD) and the dissolution behaviour of FLD was studied in the microparticles. The supercritical condition of micronized FLD occurred at a relatively high pressure and moderate temperature. FLD–PEG 4000 microparticles compared well with micronized FLD. RESS was effective in reducing the particle size of FLD; spot-shaped micronized FLD and popcorn-shaped FLD–PEG 4000 microparticles were observed. The particulate properties of the microparticles included a narrow distribution and uniform size. Thermodynamic analysis showed an implantation interaction between FLD and PEG 4000 molecules, but no polymorphism in the micronized FLD or FLD–PEG 4000 microparticles. FLD–PEG 4000 microparticles had a significantly faster drug dissolution rate than micronized FLD. These data show that RESS can be used to prepare FLD–PEG 4000 microparticles with small particle size (2–6?µm) and enhanced dissolution rate.     

白芷提取物与延胡索总碱配伍对延胡索乙素在大鼠体内药代动力学的影响

建立一种快速灵敏的大鼠体内延胡索乙素 (tetrahydropalmatine,TET) 血药浓度的HPLC-FLD检测方法;并研究白芷香豆素 (coumarin,Cou) 和挥发油 (volatile oil,VO) 两种提取物与延胡索总碱 (TA) 配伍对TET在大鼠体内药代动力学的影响。血浆经正己烷-异丙醇 (95∶5) 沉淀蛋白,HPLC-FLD检测,结果血浆中TET的线性范围为2.096～167.68 μg·L⁻¹;定量限2.096 μg·L⁻¹;方法准确度94.0%～100.0%,提取回收率72.0%～81.5%,日内日间精密度均小于7.0%;大鼠灌胃TA、TA-VO、TA-Cou、TA-VO-Cou后,TET在大鼠体内药代动力学行为均为二室开放模型,与TA组相比,配伍VO或(和) Cou后TET的AUC_0−t、AUC_0−∞、MRT_0−t、MRT_0−∞等药代动力学参数有显著差异。建立的大鼠血浆中TET的测定方法具有灵敏、准确、专属性强等特点;Cou、VO与TA配伍,能显著延长TET在大鼠体内滞留时间,减缓体内的消除,提高其生物利用度。     

Application of dense gas techniques for the production of fine particles

The feasibility of using dense gas techniques such as rapid expansion of supercritical solutions (RESS) and aerosol solvent extraction system (ASES) for micronization of pharmaceutical compounds is demonstrated. The chiral nonsteroidal anti-inflammatory racemic ibuprofen is soluble in carbon dioxide at 35°C and pressures above 90 bar. The particle size decreased to less than 2 μm while the degree of crystallinity was slightly decreased when processed by RESS. The dissolution rate of the ibuprofen (a poorly water-soluble compound) was significantly enhanced after processing by RESS. The nonsteroidal anti-inflammatory drug Cu₂(indomethacin)₄L₂(Cu-Indo); (L=dimethylformamide [DMF]), which possessed very low solubility in supercritical CO₂, was successfully micronized by ASES at 25°C and 68.9 bar using DMF as the solvent and CO₂ as the antisolvent. The concentration of solute dramatically influenced the precipitate characteristics. The particles obtained from the ASES process were changed from bipyramidal to spherical, with particle size less than 5 μm, as the concentration increased from 5 to 100 mg/g. A further increase in solute concentration to 200 mg/g resulted in large porous spheres, between 20 and 50 μ, when processing Cu-Indo by the ASES method. The dissolution rate of the micronized Cu-Indo was significantly higher than the commercial product.     

Micronization and microencapsulation of felodipine by supercritical carbon dioxide

Felodipine (FLD) is a poorly water-soluble drug. To improve its dissolution rate, the rapid expansion of supercritical solutions (RESS) technique was used to prepare micronized FLD drug particles, which were encapsulated in poly-(ethylene glycol) 4000 (PEG 4000). The physical properties of the encapsulated drug particles were characterized by a variety of analytical methods, including optical light microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and powder X-ray diffraction (powder-XRD) and the dissolution behaviour of FLD was studied in the microparticles. The supercritical condition of micronized FLD occurred at a relatively high pressure and moderate temperature. FLD-PEG 4000 microparticles compared well with micronized FLD. RESS was effective in reducing the particle size of FLD; spot-shaped micronized FLD and popcorn-shaped FLD-PEG 4000 microparticles were observed. The particulate properties of the microparticles included a narrow distribution and uniform size. Thermodynamic analysis showed an implantation interaction between FLD and PEG 4000 molecules, but no polymorphism in the micronized FLD or FLD-PEG 4000 microparticles. FLD-PEG 4000 microparticles had a significantly faster drug dissolution rate than micronized FLD. These data show that RESS can be used to prepare FLD-PEG 4000 microparticles with small particle size (2-6 microm) and enhanced dissolution rate.     

The mechanism of honokiol-induced and magnolol-induced inhibition on muscle contraction and Ca2+ mobilization in rat uterus

The effects of honokiol and magnolol extracted from the Magnolia officinalis on muscular contractile responses and intracellular Ca²⁺ mobilization were investigated in the non-pregnant rat uterus. Honokiol and magnolol (1–100 mol/l) were observed to inhibit spontaneous and uterotonic agonists (carbachol, PGF₂, and oxytocin)-, high K⁺-, and Ca²⁺ channel activator (Bay K 8644)-induced uterine contractions in a concentration-dependent manner. The inhibition rate of honokiol on spontaneous contractions appeared to be slower than that of magnolol-induced response. The time periods that were required for honokiol and magnolol, at 100 mol/l, to abolish 50% spontaneous contractions were approximately 6 min. Furthermore, honokiol and magnolol at 10 mol/l also blocked the Ca²⁺-dependent oscillatory contractions. Consistently, the increases in intracellular Ca²⁺ concentrations ([Ca²⁺]_i) induced by PGF₂ and high K⁺ were suppressed by both honokiol and magnolol at 10 mol/l. After washout of these treatments, the rise in [Ca²⁺]_i induced by PGF₂ and high K⁺ was still partially abolished. In conclusion, the inhibitory effects of honokiol and magnolol on uterine contraction may be mediated by blockade of external Ca²⁺ influx, leading to a decrease in [Ca²⁺]_i. Honokiol and magnolol may be considered as putative Ca²⁺ channel blockers and be of potential value in the treatment of gynecological dysfunctions associated with uterine muscular spasm and dysmenorrhea.     

高温致厚朴SFE-CO2萃取物中厚朴酚、和厚朴酚降解

目的了解影响厚朴中有效成分厚朴酚、和厚朴酚的不稳定因素。方法用HPLC法测定在不同实验条件下,厚朴SFE-CO₂萃取物中厚朴酚、和厚朴酚的含量;用加速实验测定有效期。结果厚朴酚、和厚朴酚的有效期(25℃)分别为387 d和476 d。结论温度是影响厚朴酚、和厚朴酚有效期的最主要因素, 降解符合一级速度反应。     

盐酸沙格雷酯对酒石酸美托洛尔大鼠体内药动学的影响

目的:考察盐酸沙格雷酯与酒石酸美托洛尔合用6 d后,酒石酸美托洛尔在大鼠体内药动学变化。方法:将40只大鼠随机分为实验组和对照组,每组20只,实验组灌胃盐酸沙格雷酯(10 mg·kg)每天3次和酒石酸美托洛尔(27 mg·kg^-1)每天一次,连续6 d;对照组灌胃酒石酸美托洛尔(27 mg·kg^-1)每天一次,连续6 d。2组于第7天灌胃给药后5 h内眼内眦取血,血浆样品处理后用UPLC-UV测定并绘制相应的药时曲线,DAS 2.1.1软件拟合药动学参数后,用SPSS 13.1软件对2组药动学参数做统计学分析。结果:实验组和对照组主要药动学参数如下:AUC_0-5h分别为(0.98±0.41) mg·h·L^-1和(0.84±0.40) mg·h·L^-1;AUC_0-∞分别为(1.08±0.42) mg·h·L^-1和(0.91±0.41) mg·h·L^-1;t_1/2分别为(1.40±0.36) h和(1.23±0.36)h;t_max分别为(0.66±0.31)h和(0.51±0.10)h;V分别为(57.02±23.46)L·kg^-1和(58.19±22.61)L·kg^-1 ;CL分别为(28.60±10.89)L·h^-1·kg^-1和(33.94±13.59)L·h^-1·kg^-1;C_max分别为(0.62±0.39)mg·L^-1和(0.71±0.40)mg·L^-1。数据显示2组间无显著性差异(P>0.05)。结论:盐酸沙格雷酯与酒石酸美托洛尔合用6 d前后,酒石酸美托洛尔在大鼠体内的药动学参数无显著性变化。     

盐酸表阿霉素长循环热敏脂质体大鼠药代动力学考察

建立一种快速、灵敏的液相色谱-串联质谱法 (LC-MS/MS) 测定大鼠血浆中微量的盐酸表阿霉素 (EPI) 浓度的方法。以盐酸柔红霉素为内标, 血浆样品用甲醇沉淀蛋白后进样, 采用CAPCELL PAK C₁₈色谱柱 (3.0 mm × 50 mm, 3 μm), 甲醇-0.1%甲酸水溶液 (80∶20) 为流动相, 以HP1200-6410 QQQ LC/MS型质谱仪多重监测 (MRM) 扫描方式检测。大鼠尾静脉注射等剂量 (12 mg·kg⁻¹) 的EPI溶液、普通脂质体 (EPI-LIP) 及长循环热敏脂质体 (EPI-LTSL), 采用DAS ver2.0软件拟合分析并求算各组药动学参数。结果血浆中EPI的线性范围为: 0.01～50 μg·mL⁻¹, 定量下限为0.01 μg·mL¹; 批内和批间精密度均小于11.9%; 平均萃取回收率分别为89.3%和92.1%; 3组药物在大鼠体内药代动力学行为均符合三室模型, EPI-LTSL组的t_1/2α、t_1/2β、t_1/2γ、AUC_0−∞、MRT_0−∞分别是EPI溶液组及EPI-LIP组的7.5、1.3、12.6、12.9、3.7倍及1.6、1.4、12.3、2.9、2.6倍, 而后两组的平均清除率 (CL) 约为EPI-LTSL组的13.4倍。EPI-LTSL能显著提高AUC并延长药物在大鼠体内的循环时间。     

Pharmacokinetic modelling of microencapsulated metronidazole

The aim of present study is to develop a pharmacokinetic model for microencapsulated metronidazole to predict drug absorption pattern in healthy human and validate this model internally.  Metronidazole was microencapsulated into ethylcellulose shells followed by the conversion of these microcapsules into tablets.  Dissolution study of tablets was conducted in 450 mL double distilled water, 0.1 mol·L⁻¹ HCl and phosphate buffer (pH 6.8) maintained at (37 ± 0.5) ℃ using USP apparatus II at 50, 100 and 150 r·min⁻¹.  Three metronidazole tablets (T₁: fast release, T₂: moderate release, T₃: slow release and reference) were administered to twenty four healthy human volunteers and serial blood samples were collected for 12 hours followed by their analysis using RP-HPLC.  Drug release data were analyzed by various model dependent and independent approaches.  Drug absorbed (%) was determined by Wagner-Nelson method from plasma concentration profile.  Internal predictability was checked from C_max and AUC.  Optimum dissolution profile was observed in double distilled water and 50 r·min⁻¹.  A good level A correlation was observed between drug dissolution and absorption profiles (correlation coefficient, R² = 0.900 9, 0.942 6, 0.901 5 and 0.932 for T₁, T₂, T₃ and reference, respectively).  Internal    predictability was found less than 10%.  Good correlation coefficients and low prediction errors elaborate the validity of this mathematical in-vitro in-vivo correlation model as a predictive tool for the determination of  pharmacokinetics from dissolution data.     

反式白藜芦醇葡萄糖苷在犬体内的药动学研究

目的：建立Beagle犬血浆中反式白藜芦醇葡萄糖苷（TRG）的测定方法并进行药动学研究。方法：Beagle犬分别灌胃和静脉给予TRG后测定不同时间的血药浓度,运用Topfit 2.0药动学软件计算非房室模型药动学参数。结果：Beagle犬以25,50,100 mg·kg^-13个剂量灌胃给予TRG,TRG血浆峰浓度（C_max）分别为（0.92±0.44）,（1.93±0.46）,（4.02±1.22）mg·L^-1;达峰时间（t_max）分别为（0.83±0.18）,（1.19±0.36）,（0.78±0.17）h;半衰期（t_1/2）分别为（0.93±0.16）,（1.18±0.19）,（1.18±0.29）h;药-时曲线下面积（AUC_0-t）分别为（1.73±0.77）,（4.14±0.52）,（8.67±2.95）mg·h·L^-1。Beagle犬静脉注射TRG 25 mg·kg^-1后,TRG的t_1/2为（1.72±0.41）h,AUC_0-t为（48.9±6.41）mg·h·L^-1,TRG的绝对生物利用度为3.53%。结论：TRG在25~100 mg·kg^-1剂量范围内C_max和AUC_0-t呈线性动力学特征,TRG在Beagle犬体内的绝对生物利用度较低。