2010 white paper on recent issues in regulated bioanalysis & global harmonization of bioanalytical guidance

The 4th Calibration and Validation Group Workshop on Recent Issues in Regulated Bioanalysis, a 2-day full immersion workshop, was organized by the Calibration and Validation Group. Contract research organizations, pharmaceutical companies and regulatory agencies came together to discuss several 'hot' topics concerning bioanalytical issues and regulatory challenges and to reach a consensus among panelists and attendees on many points regarding method validation of small and large molecules.     

Conference report: Discussion on harmonization and globalization of bioanalytical guidances at the 19th International Reid Bioanalytical Forum

The 19th International Reid Bioanalytical Forum was held in July 2011 in the UK. This open forum was an ideal meeting for extensive discussions on topics, such as global harmonization of bioanalytical guidance, in both formal and informal settings. Indeed, this meeting is well-known for its numerous networking opportunities during the 3-day conference and for an ethos of debate on practical solutions to problems encountered in bioanalytical science.     

Guideline on bioanalytical method validation

在创新药物研发过程中,生物基质（如血清、血浆、血液、尿液、唾液）中的药物浓度测定是一个重要的方面。其数据可用于支持新活性物质的应用和仿制药及已授权药品的变更申请。动物的毒代动力学研究和临床试验,包括生物等效性研究的结果为原料药或产品的安全性和有效性提供关键性的数据支持。因此,应用经过充分验证并记录到一个满意标准的生物分析方法以得到可靠的结果,这是非常重要的。2012年2月1日,欧洲药品管理局（EMA）开始实施最新的《生物样品分析方法验证指南》（Guideline on bioanalytical method validation）,本指南适用于动物的毒代动力学研究和所有阶段的临床试验中获得的生物样品中的药物浓度的生物分析方法的验证。本文摘录其方法学验证部分,抛砖引玉,供相关研究人员参考。     

Key elements of bioanalytical method validation for macromolecules

The Third American Association of Pharmaceutical Scientists/US Food and Drug Administration (FDA) Bioanalytical Workshop, which was held May 1 and 2, 2006, in Arlington, VA, addressed bioanalytical assays that are being used for the quantification of therapeutic candidates in support of pharmacokinetic evaluations. One of the main goals of this workshop was to discuss best practices used in bioanalysis regardless of the size of the therapeutic candidates. Since the last bioanalytical workshop, technological advancements in the field and in the statistical understanding of the validation issues have generated a variety of interpretations to clarify and understand the practicality of using the current FDA guidance for assaying macromolecular therapeutics. This article addresses some of the key elements that are essential to the validation of macromolecular therapeutics using ligand binding assays. Because of the nature of ligand binding assays, attempts have been made within the scientific community to use statistical approaches to interpret the acceptance criteria that are aligned with the prestudy validation and in-study validation (sample analysis) processes. We discuss, among other topics, using the total error criterion or confidence interval approaches for acceptance of assays and using anchor calibrators to fit the nonlinear regression models.     

Key elements of bioanalytical method validation for small molecules

Method validation is a process that demonstrates that a method will successfully meet or exceed the minimum standards recommended in the Food and Drug Administration (FDA) guidance for accuracy, precision, selectivity, sensitivity, reproducibility, and stability. This article discusses the validation of bioanalytical methods for small molecules with emphasis on chromatographic techniques. We present current thinking on validation requirements as described in the current FDA Guidance and subsequent 2006 Bioanalytical Methods Validation Workshop white paper.     

Aspects of bioanalytical method validation for the quantitative determination of trace elements

Bioanalytical methods are used to quantitatively determine the concentration of drugs, biotransformation products or other specified substances in biological matrices and are often used to provide critical data to pharmacokinetic or bioequivalence studies in support of regulatory submissions. In order to ensure that bioanalytical methods are capable of generating reliable, reproducible data that meet or exceed current regulatory guidance, they are subjected to a rigorous method validation process. At present, regulatory guidance does not necessarily account for nuances specific to trace element determinations. This paper is intended to provide the reader with guidance related to trace element bioanalytical method validation from the authors' perspective for two prevalent and powerful instrumental techniques: inductively coupled plasma-optical emission spectrometry and inductively coupled plasma-MS.     

Method validation in the bioanalytical laboratory

Bioanalytical methods, based on a variety of physico-chemical and biological techniques such as chromatography, immunoassay and mass spectrometry, must be validated prior to and during use to engender confidence in the results generated. The fundamental criteria for assessing the reliability and overall performance of a bioanalytical method are: the evaluation of drug and analyte stability, selectivity, limits of quantification and detection, accuracy, precision, linearity and recovery. The extent to which a method is validated is dependent on its prospective use, the number of samples to be assayed and the use to which the data are put.

Specific analytical techniques may require additional validation such as antibody-binding characteristics, peak purity determination, evaluation of matrix effects or structural confirmation of the analyte. Ideally each assay should be cross-validated with a method utilizing a highly specific detector such as a mass spectrometer. Once in use, the performance of the method should be monitored using quality control standards. If a method is set up in another laboratory, the performance of the assay should be monitored with quality control standards sent from the originating laboratory.     

Application issues in bioanalytical method validation,sample analysis and data reporting

Although some degree of consensus has been reached concerning the requirements for acceptable method validation, the procedures used to establish them vary significantly between laboratories. Also, issues arising from application of these requirements during validation and subsequent sample analysis need to be addressed. The purpose of this paper is to discuss application issues concerning prerequisites to method validation, and all validation criteria for evaluation of method reliability and overall performance. Other poorly addressed issues such as re-validation, cross-validation, partial sample volume, multicomponent analysis and reporting will also be discussed. Although many issues discussed are of a general nature, the scope of this presentation is primarily to address issues arising from the validation and routine application of chromatographic methods.     

Development and validation of bioanalytical method for the determination of asulacrine in plasma by liquid chromatography

Asulacrine (9-[(2-methoxy-4-methylsulphonylamino)phenylamino]-N,5-dimethyl-4-acridinecarboxamide), an analogue of the antileukaemia drug amsacrine, has high antitumour activity in mice and has also shown clinical activity. A simple method is described for the quantitation of asulacrine in plasma by liquid chromatography. Chromatographic separation was achieved on a reversed phase C 18 column (250 mm x 4.6mm, particle size 5 microm, Gemini) using isocratic elution (acetonitrile and 0.01 M sodium acetate buffer pH 4.0, 45/55, v/v) at a flow rate of 1 ml/min. Asulacrine and internal standard (the ethylsulphonanilide analogue) were measured using UV detection at 254 nm. The total chromatographic run-time was 8 min with asulacrine and internal standard eluting at approximately 4.7 and approximately 6.5 min, respectively. Limit of quantification was 0.1microg/ml. The linearity range of the method was 0.1-10 microg/ml (r2=0.9995). Mean recoveries from plasma were 100-105%. Intra-batch and inter-batch precision was 7.1 and 7.8%, respectively, and intra-batch and inter-batch accuracy (relative error) was 4.9 and 8.4%, respectively (n=8 in all cases). The bench top, freeze thaw, short-term storage and stock solution stability evaluation indicated no evidence of degradation of asulacrine. The validated method is simple, selective and rapid and can be used for pharmacokinetic studies in mice.     

Development and validation of a high-performance liquid chromatographic method for bioanalytical application with rimonabant

A simple and feasible high-performance liquid chromatographic method with UV detection was developed and validated for the quantification of rimonabant in human plasma. The chromatographic separation was carried out in a Hypersil BDS, C₁₈ column (250 mm × 4.6 mm; 5 μm). The mobile phase was a mixture of 10 mM phosphate buffer and acetonitrile (30:70, v/v) at a flow rate of 1.0 ml/min. The UV detection was set at 220 nm. The extraction recovery of rimonabant in plasma at three quality control (QC) samples was ranged from 84.17% to 92.64%. The calibration curve was linear for the concentration range of 20–400 ng/ml with the correlation coefficient (r²) above 0.9921. The method was specific and sensitive with the limit of quantification of 20 ng/ml. The accuracy and precision values obtained from six different sets of QC samples analyzed in separate occasions ranged from 88.13% to 106.48% and 0.13% to 3.61%, respectively. In stability tests, rimonabant in human plasma was stable during storage and assay procedure. The method is very simple, sensitive and economical and the assay was applied to human plasma samples in a clinical (pharmacokinetic) study of rimonabant.     

EBF recommendation on the validation of bioanalytical methods for dried blood spots

Over the last few years bioanalysts, pharmacokineticists and clinical investigators have rediscovered the technique of dried blood spots. The revival has provided pharmaceutical R&D a wealth of opportunities to optimize the drug-discovery and development process with respect to animal and patient ethics, new scientific insights and costs savings. On the bioanalytical front, multiple experiments have been performed and a lot of experience has been gained. Nevertheless, the technique still has a number of bioanalytical challenges. The European Bioanalysis Forum discussed the advantages and hurdles of the technique and summarized their current thinking in a recommendation on the validation of bioanalytical methods for dried blood spots, which can be used as a cornerstone for further discussions and experiments.     

A comprehensive method validation strategy for bioanalytical applications in the pharmaceutical industry--1. Experimental considerations

The method validation strategy described consists of four components which are the prevalidation, validation proper, study proper and statistical analyses. These components constitute the platform upon which to evaluate the reliability and reproducibility of a bioanalytical method. Consideration has been given to emulate the study proper conditions to understand the method's limitations and performance expectations. The validation strategy will be presented in two papers. This first paper will describe the overall validation strategy, and the second paper will discuss the statistical analyses and data interpretation.     

A comprehensive method validation strategy for bioanalytical applications in the pharmaceutical industry--2. Statistical analyses.

The first paper in this two-part series described [Lang and Bolton, J. Pharm. Biomed. Anal. 9, 357-361 (1991)] an overall validation strategy for bioanalytical methods. This second paper focuses on the statistical analyses performed on the validation data that will allow the analyst to evaluate the reliability and reproducibility of a bioanalytical method. Based on the validation results, acceptance criteria for the quality control concentrations are established and used during the study proper to determine if the analytical run is valid. After analysing the clinical study samples and accepting the analytical runs, the quality control results are incorporated into databases to update their acceptance limits. This continuous validation process enables the analyst to monitor the method's performance over time and be confident that accurate sample concentrations are being reported. It is important to emphasize that the statistical analyses of the data provide information that should be considered from a practical point of view by the analyst. The analyst should use sound judgement in evaluating the reliability of the method.     

US FDA/EMA harmonization of their bioanalytical guidance/guideline and activities of the Global Bioanalytical Consortium

The 2011 annual conference of the American Association of Pharmaceutical Scientists, held in Washington DC, USA, hosted a roundtable entitled: 'Update of the US FDA/European Medicines Agency (EMA) harmonization of their bioanalytical guidance - Global Bioanalytical Consortium activity and impact on small and large molecules.' The roundtable was initiated with a presentation from CT Viswanathan on the history of the revision of the FDA guideline on bioanalytical method validation. It was followed by a presentation by Jan Welink who presented an update on the final European Medicines Agency guideline on bioanalytical method validation with relevance to ongoing harmonization efforts. The final presentation was by Fabio Garofolo on the progress of the Global Bioanalytical Consortium harmonization teams for small and large molecules. Brian Booth and Sam Haidar of the FDA updated the audience on the status of the revision of the FDA bioanalytical guidance. The roundtable was moderated by Stephen Lowes.     

Regulatory recommendations for clopidogrel: Focus on validation of a reliable bioanalytical method and its application to a bioequivalence study

A rapid, simple, and sensitive liquid chromatography tandem mass spectrometric (LC–MS/MS) method for the determination of clopidogrel in human plasma was developed and validated using clopidogrel-d4 as the internal standard (IS). The analyte and the IS were extracted from 500 µl aliquots of human plasma via solid phase extraction. The precursor to product ion transitions monitored for clopidogrel and IS were m/z 322.2 → 212.0 and 326.2 → 216.0, respectively. The method was fully validated for sensitivity, accuracy and precision, linearity, recovery, matrix effect, dilution integrity, and stability. The Linearity range was 20.4–10,772.6 pg/mL with mean correlation coefficient (r) ≥ 0.9977. The back conversion was also evaluated during method validation as per EMA recommendation. Results proved that clopidogrel was accurately and reliably estimated by the method without any evidence of back conversion of clopidogrel acid. The method was successfully applied to a bioequivalence study of 75?mg clopidogrel bisulfate tablet formulation in 32 healthy male volunteers under fasting conditions. The ratios of least-squares means (with 90% confidence intervals) for the pharmacokinetic parameters C_max, AUC_0–t and AUC_0–α were 107.98% (94.52–123.35%), 100.25% (91.28–110.09%), and 100.49% (91.37–110.51%), respectively.