CYP2A6*4基因多态性对右美托咪定药动学的影响

目的: 在CYP2A6*4突变频率高的中国人中测定CYP2A6*4等位基因对右美托咪定药代动力学的影响,为临床提供参考。方法: 31名手术患者通过静脉泵接受0.5 μg/kg右美托咪定后,抽取多个时间点的血样,测定血药浓度以及CYP2A6*4的多态性,并进行统计分析。结果: 9名患者为*1/*4或*4/*4,22名患者为*1/*1。主要药代动力学参数如下,曲线下面积（AUC）为（1 396.19±332.47）h·ng·L^-1,峰值血药浓度（C _max）为（495.50±104.90）ng/L,分布容积（V）为（0.68±0.20）L/kg,清除率（CL）为（0.38±0.11）L·h ^-1·kg^-1,分布半衰期（t _1/2α）为（0.05±0.01）h,消除半衰期（t _1/2β）为（2.53±0.04）h。在CYP2A6*1/*1,*1/*4和*4/*4患者中未发现显著的药代动力学差异。结论: 中国患者使用右美托咪定后,t _1/2β与公布的一致,但t _1/2α,V和CL较低。在制定右美托咪定的精准治疗方案时,可不予考虑CYP2A6*4突变。     

Synthesis and Biological Characterization of Amidopropenyl Hydroxamates as HDAC Inhibitors

A series of amidopropenyl hydroxamic acid derivatives were prepared as novel inhibitors of human histone deacetylases (HDACs). Several compounds showed potency at <100 nM in the HDAC inhibition assays, sub‐micromolar IC₅₀ values in tests against three tumor cell lines, and remarkable stability in human and mouse microsomes was observed. Three representative compounds were selected for further characterization and submitted to a selectivity profile against a series of class I and class II HDACs as well as to preliminary in vivo pharmacokinetic (PK) experiments. Despite their high microsomal stability, the compounds showed medium‐to‐high clearance rates in in vivo PK studies as well as in rat and human hepatocytes, indicating that a major metabolic pathway is catalyzed by non‐microsomal enzymes.     

From a library of MAG antagonists to nanomolar CD22 ligands

Siglec-2, also known as CD22, is involved in the regulation and survival of B-cells and has been successfully targeted in cell depletion therapies with antibody-based approaches. Sialic acid derivatives, already known to bind with high affinity to myelin-associated glycoprotein (MAG, Siglec-4), were screened for their binding affinity for CD22 by surface plasmon resonance. The best compound identified was further modified with various hydrophobic substituents at the 2-, 5-, and 9-positions of the sialic acid scaffold, leading to nanomolar derivatives, of which ligand 17 b shows the most promising pharmacodynamic and pharmacokinetic profiles. Isothermal titration calorimetry measurements demonstrate that the binding is enthalpy driven. Interestingly, the thermodynamic fingerprints reveal an excellent correlation between gains in enthalpy and compensation by increased entropy costs. Moreover, 17 b exhibits a residence time in the range of a few seconds, clearly prolonged relative to residence times typically observed for carbohydrate-lectin interactions. Finally, initial tests regarding drug-like properties of 17 b demonstrate the required high plasma protein binding yet a lack of oral availability, although its distribution coefficient (log D) is in the required range.     

人体中伊曲康唑及其活性代谢产物羟基伊曲康唑的整合药代动力学研究

目的: 羟基伊曲康唑(OH-ITZ)为目前临床一线抗真菌药伊曲康唑(ITZ)的主要活性代谢产物,其与ITZ有着相似的抗菌活性,且血药浓度较母体药物高,因此OH-ITZ的体内过程对临床疗效的影响研究不容忽视。本文旨在建立灵敏、快速的液相色谱-串联质谱法同时测定人血浆中ITZ及OH-ITZ,并应用整合药代动力学模型进行整体评价。方法: 血浆样品经沉淀蛋白后,以乙腈(甲酸 0.1%)-水(甲酸 0.1%)为流动相梯度洗脱,Zorbax XDB C₁₈柱分离,采用电喷雾电离源,以多反应监测(MRM)方式进行正离子检测。定量分析所用的离子反应分别为m/z 705 →m/z 392(ITZ),m/z 721→m/z 408(OH-ITZ)和m/z 386→m/z 122(内标,丁螺环酮)。结果: 测定血浆中ITZ及OH-ITZ的线性范围均为 0.50~500 ng/mL,日内、日间精密度(RSD)均小于 12.4%,准确度(RE)均在±7.5%以内;整合药动学研究结果显示综合浓度药-时曲线符合口服给药药物消除规律,整合后主要药动学参数t_1/2和AUC_0-∞分别为 19.5 h,5754 ng·h·mL^-1。结论: 本方法运行时间短、选择性强、灵敏度高、操作简便、血浆用量少,适用于ITZ及OH-ITZ的临床药代动力学研究;其整合药动学模型研究所获参数能够表征ITZ和OH-ITZ的整体处置规律,符合经典药代动力学模型特征。     

Development and pharmacokinetic evaluation of alginate-pectin polymeric rafts forming tablets using box behnken design

Abstract

Raft is an emerging drug delivery system, which is suitable for controlled release drug delivery and targeting. The present study aimed to evaluate the physico-chemical properties of raft, in vitro release of pantoprazole sodium sesquihydrate and conduct bioavailability studies. Box behnken design was used with three independent and dependent variables. Independent variables were sodium alginate (X₁), pectin (X₂) and hydroxypropyl methyl cellulose K100M (X₃) while dependent variables were percentage drug release at 2 (Y₂), 4 (Y₄) and 8?h (Y₈). The developed rafts were evaluated by their physical and chemical properties. Fourier transform infrared spectroscopy and differential scanning calorimetry were used to study the chemical interaction and thermal behaviour of drug with polymers. Alginate and pectin contents of R9 formulation were 99.28% and 97.29%, respectively, and acid neutralization capacity was 8.0. R9 formulation showed longer duration of neutralization and nature of raft was absorbent. The raft of R9 formulation showed 98.94% release of PSS at 8?h in simulated gastric fluid. Fourier transform infrared spectroscopy showed no chemical interaction and differential scanning calorimetry indicated endothermic peaks at 250?°C for pantoprazole sodium sesquihydrate. t_max for the test and reference formulations were 8?±?2.345?h and 8?±?2.305?h, respectively. C_max of test and reference formulations were 46.026?±?0.567?µg/mL and 43.026?±?0.567?µg/mL, respectively. AUC_(0-t) of the test and reference formulations were 472.115?±?3.467?µg?×?h/mL and 456.105?±?2.017?µg?×?h/mL, respectively. Raft forming system successfully delivered the drug in controlled manner and improved the bioavailability of drugs.     

125I示踪法研究rhPTH(1～34)在大鼠体内的药代动力学

采用125I标记重组人甲状旁腺素（1～34）肽（Recombinant Human Parathyroid hormone（1～34），rhPTH（1～34））示踪技术，研究rhPTH(1～34)在SD大鼠体内的药代动力学。结果显示，SD大鼠单次皮下给予1.8和3.6μg/kg剂量的rhPTH1-34后，其主要药代动力学参数为：达峰时间Tmax为0.26±0.07 h和0.25±0.0 h，血浆峰浓度为1.30±0.17 μg/L和3.20±1.12μg/L，末端消除半衰期T1/2el为1.70±0.56 h和1.58±0.70 h，药物浓度－时间曲线下面积AUC(0-∞)为3.1±0.7 μg•h /L和6.7±0.7 μg•h /L。表明大鼠单次皮下给予rhPTH(1～34)后，在给药后大约0.25 h血药浓度达到峰值，随后出现一个较快的消除过程，其药代动力学特征符合非静脉给药线性一房室模型一级动力学。     

Comparative Neuropharmacology and Pharmacokinetics of Methamphetamine and Its Thiophene Analog Methiopropamine in Rodents

Methiopropamine is a novel psychoactive substance (NPS) that is associated with several cases of clinical toxicity, yet little information is available regarding its neuropharmacological properties. Here, we employed in vitro and in vivo methods to compare the pharmacokinetics and neurobiological effects of methiopropamine and its structural analog methamphetamine. Methiopropamine was rapidly distributed to the blood and brain after injection in C57BL/6 mice, with a pharmacokinetic profile similar to that of methamphetamine. Methiopropamine induced psychomotor activity, but higher doses were needed (E_max 12.5 mg/kg; i.p.) compared to methamphetamine (E_max 3.75 mg/kg; i.p.). A steep increase in locomotor activity was seen after a modest increase in the methiopropamine dose from 10 to 12.5 mg/kg, suggesting that a small increase in dosage may engender unexpectedly strong effects and heighten the risk of unintended overdose in NPS users. In vitro studies revealed that methiopropamine mediates its effects through inhibition of norepinephrine and dopamine uptake into presynaptic nerve terminals (IC₅₀ = 0.47 and 0.74 µM, respectively), while the plasmalemmal serotonin uptake and vesicular uptake are affected only at high concentrations (IC₅₀ > 25 µM). In summary, methiopropamine closely resembles methamphetamine with regard to its pharmacokinetics, pharmacodynamic effects and mechanism of action, with a potency that is approximately five times lower than that of methamphetamine.     

In Vitro/In Vivo Translation of Synergistic Combination of MDM2 and MEK Inhibitors in Melanoma Using PBPK/PD Modelling: Part I

Translation of the synergy between the Siremadlin (MDM2 inhibitor) and Trametinib (MEK inhibitor) combination observed in vitro into in vivo synergistic efficacy in melanoma requires estimation of the interaction between these molecules at the pharmacokinetic (PK) and pharmacodynamic (PD) levels. The cytotoxicity of the Siremadlin and Trametinib combination was evaluated in vitro in melanoma A375 cells with MTS and RealTime-Glo assays. Analysis of the drug combination matrix was performed using Synergy and Synergyfinder packages. Calculated drug interaction metrics showed high synergy between Siremadlin and Trametinib: 23.12%, or a 7.48% increase of combined drug efficacy (concentration-independent parameter β from Synergy package analysis and concentration-dependent δ parameter from Synergyfinder analysis, respectively). In order to select the optimal PD interaction parameter which may translate observed in vitro synergy metrics into the in vivo setting, further PK/PD studies on cancer xenograft animal models coupled with PBPK/PD modelling are needed.     

Losartan Potassium and Verapamil Hydrochloride Compound Transdermal Drug Delivery System: Formulation and Characterization

In this study, we developed a sustained-release transdermal delivery system containing losartan potassium (LP) and verapamil hydrochloride (VPH). LP and VPH have low bioavailability and long half-life. Therefore, the development of an optimum administration mode is necessary to overcome these drawbacks and enhance the antihypertensive effect. A transdermal diffusion meter was used to determine the optimal formulation of LP-VPH transdermal drug delivery systems (TDDS). Based on in vitro results, a sustained-release patch was prepared. Physical characteristics, including quality, stickiness, and appearance, were evaluated in vitro, while pharmacokinetics and skin irritation were evaluated in vivo. The results showed that 8.3% polyvinyl alcohol, 74.7% polyvinylpyrrolidone K30, 12% oleic acid-azone, and 5% polyacrylic acid resin II provided an optimized TDDS product for effective administration of LP and VPH. Furthermore, in vitro and in vivo release tests showed that the system continuously released LP and VPH for 24 h. The pharmacokinetic results indicated that although the maximum concentration was lower, both the area under the curve from 0–time and the mean residence time of the prepared patch were significantly higher than those of the oral preparations. Furthermore, the prepared LP-VPH transdermal patch showed good stability and no skin irritation. The developed LP-VPH TDDS showed a sustained-release effect and good characteristics and pharmacokinetics; therefore, it is an ideal formulation.     

In Vivo Bio-Activation of JWH-175 to JWH-018: Pharmacodynamic and Pharmacokinetic Studies in Mice

3-(1-Naphthalenylmethyl)-1-pentyl-1H-indole (JWH-175) is a synthetic cannabinoid illegally marketed for its psychoactive cannabis-like effects. This study aimed to investigate and compare in vitro and in vivo pharmacodynamic activity of JWH-175 with that of 1-naphthalenyl (1-pentyl-1H-indol-3-yl)-methanone (JWH-018), as well as evaluate the in vitro (human liver microsomes) and in vivo (urine and plasma of CD-1 male mice) metabolic profile of JWH-175. In vitro binding studies showed that JWH-175 is a cannabinoid receptor agonist less potent than JWH-018 on mouse and human CB1 and CB2 receptors. In agreement with in vitro data, JWH-175 reduced the fESPS in brain hippocampal slices of mice less effectively than JWH-018. Similarly, in vivo behavioral studies showed that JWH-175 impaired sensorimotor responses, reduced breath rate and motor activity, and increased pain threshold to mechanical stimuli less potently than JWH-018. Metabolic studies demonstrated that JWH-175 is rapidly bioactivated to JWH-018 in mice blood, suggesting that in vivo effects of JWH-175 are also due to JWH-018 formation. The pharmaco-toxicological profile of JWH-175 was characterized for the first time, proving its in vivo bio-activation to the more potent agonist JWH-018. Thus, it highlighted the great importance of investigating the in vivo metabolism of synthetic cannabinoids for both clinical toxicology and forensic purposes.