内源性物质药物生物等效性评价的探讨

内源性物质是体内已有的物质,内源性物质药物生物等效性的评价因为体内自身物质的存在变得复杂化。文中以内源性物质和生物等效性为关键词,检索Pubmed和万方数据库,对常用的内源性物质药物的生物等效性评价方法进行了综述。     

生物等效性评价及相关问题

生物等效性在新药研究、非专利药开发和药品上市后评价中具有重要作用。本文从实验方法学、药剂因素、内源性物质、活性代谢物、立体异构药物和高变异性药物等方面对生物等效性研究在技术指南及实际应用中需要特别注意的问题进行了具体论述,同时对生物药剂学分类系统等生物等效性研究的相关进展做了初步介绍。     

浅析生物等效性试验风险管理策略

仿制药一致性评价推动着生物等效性试验的开展,生物等效性试验的风险日益突出。本文基于临床试验管理者的视角,对生物等效性试验实施过程中的机构组织管理、受试者管理、试验药物和生物样品管理风险现状及存在问题进行剖析,提出加强对机构管理者及研究者生物等效性试验专业知识和法规的培训、关注受试者招募合规性及试验期间管理的合理性、规范试验药物和生物样品的管理流程和记录等相应的风险管控措施和策略。     

人体生物等效性试验中生物样品分析的关键问题研究

采用体内生物等效性试验的方法开展一致性评价是仿制药申请的基础,生物等效性试验首选药动学研究的方法,而药动学中生物样品分析是最为重要的环节,它将直接影响药品的安全性和有效性,为生物等效性试验的结果做出关键性决定。目前我国的生物样品分析质量还有很大提升空间,基于此,本文根据相关指导原则,结合工作实际,针对生物等效性试验中生物样品分析方法的建立、验证、测试、记录和注意事项等,探讨生物等效性试验中生物样品分析的关键问题。     

重组蛋白多肽药物生物等效性研究的必要性、可行性和方法学

首先简单综述了国外对重组蛋白或多肽生物等效性研究的概况和实例。重点讨论了药品生产厂家和管理当局对药物开发不同阶段生物等效性评价必要性的认识,介绍了生物等效性评价的方法和结果。然后详细介绍了本实验室进行重组蛋白或多肽药物生物等效性研究的经验、方法和结果。最后强调了生物等效性研究对于化学药物和生物制品的同等重要性。重组蛋白或多肽药物浓度测定常用方法是酶联免疫吸附测定（ELISA）,必要时也可用生物检定法测定活性浓度。     

浅谈高变异药物的生物等效性研究

高变异药物的生物等效性研究是一个引人关注的现实课题，本文分析和介绍了高变异药物生物等效性研究的困难及其主要解决方法，希望能够有助于国内临床研究单位加强对高变异药物生物等效性研究问题的重视，从而更加科学可靠地评价高变异药物的生物等效性。     

对含盐酸二甲双胍制剂生物等效性试验若干问题的探讨

通过分析盐酸二甲双胍制剂生物等效性试验文献资料,结合我们的相关研究,探讨了目前国内药物制剂生物等效性试验存在的问题,并提出相应对策。荟萃分析表明,我国在盐酸二甲双胍制剂生物等效性试验的生物样品分析测定、试验管理、设计与实施、试验结果及讨论分析方面均存在一定问题,提示应进一步规范生物等效性试验,通过药物上市后再评价以提高我国上市药品的有效性、安全性和经济性。     

药物制剂生物利用度和生物等效性试验指导原则(草案)

参考国际上的相关指导原则,对《中国药典》2015年版药物制剂生物利用度和生物等效性指导原则提出了修改草案。包括前言,常释制剂生物等效性试验的设计、实施和评价,调释制剂和透皮吸收制剂的生物等效性试验,试验报告,与生物等效性试验相关的体外溶出度检查,对不同剂型的生物等效性要求,以及基于生物药剂学分类系统的生物豁免。与现行药典指导原则相比,把生物样品定量分析方法的内容分离出去,对试验药品的规格、参比制剂选取、测试原形药物还是代谢物、高变异性药品生物等效性等提供了新的建议,强调溶出度实验的意义,并引入了生物试验豁免的相关内容。     

国内奥美拉唑(盐)口服制剂人体生物等效性试验的问题和对策

奥美拉唑是质子泵抑制剂类代表药物,临床上应用广泛.文中通过对国内26篇奥美拉唑(盐)12服制剂人体生物等效性试验文献进行分析,探讨了试验内容、参比制剂、受试者、生物样品采集及分析、药动学参数、上市后生物等效性再评价或监测等方面的问题和对策,以期为奥美拉唑(盐)口服制剂人体生物等效性研究和临床应用提供参考信息,并基于现有...     

美国FDA《特定药物的生物等效性指导原则》 高变异性药物生物等效性指导原则调研

目的：研究美国食品药品管理局（FDA）《特定药物的生物等效性指导原则》对高变异性药物生物等效性研究相关规定,为我国仿制药质量和疗效一致性评价工作提供借鉴和帮助。方法：从剂型、给药方式、试验设计、受试者选择、给药条件、检测物质选择、豁免条件、体外溶出试验等多个方面对美国FDA公布的高变异性药物《特定药物的生物等效性指导原则》进行详细分析,并特别指出涉及我国仿制药质量与疗效一致性评价首批品种的高变异性药物。结果：美国FDA公布的涉及高变异性药物《特定药物的生物等效性指导原则》对具体化学仿制药的生物等效性评价从多个方面进行较为详细的规范,是对美国FDA相关生物等效性总则的补充和解读,对仿制药的发展有重要的推动作用。结论：在我国国家食品药品监督管理总局（CFDA）尚未颁布针对具体高变异性药物相关生物等效性指导原则的背景下,美国FDA《特定药物的生物等效性指导原则》中对高变异性药物相关规范对我国正在进行的仿制药质量和疗效一致性评价具有一定指导和借鉴意义。     

Determination of the antihyperlipidemic simvastatin by various voltammetric techniques in tablets and serum samples

The electrochemical behavior and determination of simvastatin (SMV), a lipid-lowering drug, were studied in aqueous alcohol medium at a stationary glassy carbon electrode. Cyclic voltammetry studies showed one main, well-defined, sharp oxidation peak between pH 2 and 8. The oxidation was irreversible and exhibited a diffusion controlled mechanism. Differential pulse and square wave voltammetric methods for the quantitative determination of SMV in pharmaceutical dosage forms and spiked serum samples were developed based on the linear relationship between the peak current and the concentration. Differential pulse and square wave voltammetric techniques for the determination of SMV in 0.1 M H2SO4 and a constant amount of methanol (20%), which allow quantitation over the 2 x 10(-6)-1 x 10(-4) M range in supporting electrolyte with a detection limit of 2.71 x 10(-7) M and 5.50 x 10(-7) M for differential pulse and square wave voltammetric methods, respectively, are proposed. The repeatability and reproducibility of the methods were determined. Precision and accuracy were also checked. These methods were used for the determination of SMV in tablets. The standard addition method was used in biological media. No electroactive interferences from endogenous substances and excipients were found in biological fluids and pharmaceutical dosage forms, respectively.     

Qualitative and quantitative chromatographic investigation of flavonoids in Pyrus communis L. flowers

The qualitative and quantitative analysis of flavonoids, and the quantitative determination of procyanidins in the flowers of naturally growing Pyrus communis and in the flowers of cultivated varieties were carried out. The flavonoid compounds were investigated by chromatographic methods. The flavonoid samples were found in all the studied plant materials. The content of flavonoids was determined by the Christ-Müller's and HPLC methods after acid hydrolysis. The quantitative determination of procyanidins was carried out by the spectrophotometric method.     

Autoradiography, MALDI-MS, and SIMS-MS Imaging in Pharmaceutical Discovery and Development

Whole-body autoradiography ((WBA) or quantitative WBA (QWBA)), microautoradiography (MARG), matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI), and secondary ion mass spectrometric imaging (SIMS-MSI) are high-resolution, molecular imaging techniques used to study the tissue distribution of radiolabeled and nonlabeled compounds in ex vivo, in situ biological samples. WBA, which is the imaging of the whole-body of lab animals, and/or their organ systems; and MARG, which provides information on the localization of radioactivity in histological preparations and at the cellular level, are used to support drug discovery and development efforts. These studies enable the conduct of human radiolabeled metabolite studies and have provided pharmaceutical scientists with a high resolution and quantitative method of accessing tissue distribution. MALDI-MSI is a mass spectrometric imaging technique capable of label-free and simultaneous determination of the identity and distribution of xenobiotics and their metabolites as well as endogenous substances in biological samples. This makes it an interesting extension to WBA and MARG, eliminating the need for radiochemistry and providing molecular specific information. SIMS-MSI offers a complementary method to MALDI-MSI for the acquisition of images with higher spatial resolution directly from biological specimens. Although traditionally used for the analysis of surface films and polymers, SIMS has been used successfully for the study of biological tissues and cell types, thus enabling the acquisition of images at submicrometer resolution with a minimum of samples preparation.     

Mass spectrometry-based quantitative analysis and biomarker discovery

Mass spectrometry-based quantitative analysis and biomarker discovery using metabolomics approach represent one of the major platforms in clinical fields including for the prognosis or diagnosis, assessment of severity and response to therapy in a number of clinical disease states as well as therapeutic drug monitoring (TDM). This review first summarizes our mass spectrometry-based research strategy and some results on relationship between cysteinyl leukotriene (cysLT), thromboxane (TX), 12-hydroxyeicosatetraenoic acid (12-HETE) and other metabolites of arachidonic acid and diseases such as atopic dermatitis, rheumatoid arthritis and diabetes mellitus. For the purpose of evaluating the role of these metabolites of arachidonic acid in disease status, we have developed sensitive determination methods with simple solid-phase extraction and applied in clinical settings. In addition to these endogenous compounds, using mass spectrometry, we have developed actually applicable quantitative methods for TDM. Representative example was a method of TDM for sirolimus, one of the immunosuppressant agents for a recipient of organ transplant, which requires rigorous monitoring of blood level. As we recognized great potential in mass spectrometry during these researches, we have become interested in metabolomics as the non-targeted analysis of metabolites. Now, established strategy for the metabolomics investigation applies to samples from cells, animals and humans to separate groups based on altered patterns of metabolites in biological fluids and to identify metabolites as potential biomarkers discriminating groups. We would be honored if our research using mass spectrometry would contribute to provide useful information in the field of medical pharmacy.     

Quantitative GLC determination of cis- and trans-isomers of doxepin and desmethyldoxepin

A GLC method for the simultaneous quantitative determination of the cis- and trans-isomers of doxepin and desmethyldoxepin in human plasma was developed. The method involves the use of a capillary column for efficient separation of the four compounds and the internal standards, amitriptyline and nortriptyline. A high sensitivity is obtained with a nitrogen detector, enabling quantitation of the compounds in plasma of humans treated chronically with doxepin. Confirmation of the identity of the cis- and trans-isomers of doxepin and desmethyldoxepin in biological samples was carried out by selected ion monitoring.     

Development of highly sensitive determination of biogenic compounds by high-performance liquid chromatography with pre-column fluorescence derivatization

A sensitive fluorescent labeling reagent, 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride (DMS-Cl), for the determination of amino compounds in HPLC was developed. DMS-Cl reacted with amino compounds in the basic medium to produce the corresponding fluorescent sulfonamides (excition 318 nm, emission 406 nm in aqueous acetonitrile). When amino acids were analyzed using reverse-phase HPLC, the detection limits (signal-to-noise ratio = 3) of almost all amino acids labeled with DMS-Cl were less than 5 fmol/injection. DMS-Cl was utilized for highly sensitive determination of amino compounds in biological samples and HPLC methods for determination of prolyl dipeptides, Pro and Hyp, in serum and urine, pipecolic acid in serum, taurine in plasma, and free and N-acetylated polyamine in urine were established. As these proposed methods are highly sensitive and reproducible and require only a small amount of biological sample, they may be useful for clinical and biochemical research.     

植物内源激素检测方法新进展

植物内源激素是植物体内产生的一类小分子化合物,在极低的浓度下就能发挥多种生理作用,调控植物生长发育的每一过程。植物内源激素在植物体内含量极低、性质不稳定,其定量检测一直是当前研究的热点和难点。随着分析技术的进步及新仪器的出现,植物内源激素的提取和纯化技术及检测方法也在不断更新。目前,有机溶剂提取、固相萃取柱纯化是常用的提取和纯化步骤,检测方法主要包括生物鉴定法、理化检测法和免疫检测法3大类,其中理化检测是最常用方法。本文对近几年植物内源激素提取、纯化和检测方法 3个方面的新进展进行综述,以期为植物内源激素的深入研究提供参考。     

Two chromatographic methods for the determination of corticosteroids in human biological fluids: pharmacokinetic applications

Two techniques, high-performance liquid chromatography (HPLC) and quantitative high-performance thin-layer chromatography coupled with densitometry (HPTLC), were developed for the determination of prednisolone (PL), methylprednisolone (MP), and methylprednisolone sodium succinate (MPSS) in human plasma, saliva, and urine. The HPLC and HPTLC methods shared a single and simple step of an organic extraction procedure and separation of steroids using a normal-phase column or HPTLC plate. The methods allow simultaneous measurement of endogenous cortisol in plasma following the administration of PL and MP. The calibration curves of steroids in all biological fluids were linear over a wide range of concentrations of PL and MP in all biological fluids (0.025-4 micrograms/mL). The limit of detection of both assays for PL and MP was 10 ng/mL in plasma and saliva and 25 ng/mL in urine, and of MPSS was 50 ng/mL in plasma. Both methods were reproducible with an inter- and intra-assay coefficient of variation of less than 10% for all steroids over a wide range of concentrations in all biological fluids. No interference from endogenous steroids was found. The presented methods are simple, rapid, specific, sensitive, reproducible, and economical for the pharmacokinetic study of these steroids. The application of these methods for the pharmacokinetic study of both MP and PL in vivo and the in vitro hydrolysis of MPSS is discussed.     

TLC determination of iodochlorhydroxyquin and its conjugate in plasma.

A simple, specific, reliable, and sensitive method for the determination of iodochlorhydroxyquin and/or its conjugate in biological fluids is described. The method is based on a quantitative ether-acetone (1:1) extraction of plasma samples followed by TLC separation, visualization, elution, and determination at 267 nm. Iodochlorhydroxyquin released by hydrolysis of its conjugate was analyzed. Both compounds are detectable in amounts as low as 0.04 microgram/ml. Application of the one-compartment open model to the data (assuming the biotransformation of the drug in conjugated form) provides a pharmacokinetic profile for the 50-mg/kg dose of iodochlorhydroxyquin in Wistar male rats.     

Applicability of the silver amalgam electrode in voltammetric determination of zinc and copper in gastric juice and gastric mucosa of rats

The aim of the work was to compare two analytical methods of trace analysis in respect to their applicability in heavy metals determination in biological samples. Atomic absorption spectrometry (AAS) may be considered as the method of choice in such analyses due to its accuracy, precision and low detection limit. On the other hand, voltammetric methods seem to be as useful, but rarely applied. Having in mind that there is no universal analytical method, we have compared two AAS and voltammetric methods as the tools for Zn and Cu determination in the samples collected from rat gastric juice and gastric mucosa. Construction of the renewable silver amalgam film electrode (Hg(Ag)FE) for stripping voltammetry was described. Detailed optimization of measurements procedure and sample preparation for differential pulse anodic stripping voltammetry (DP ASV) and AAS were also performed and presented. The obtained results of quantitative analysis of the chosen parameters by means of both methods are discussed.