Analysis of 2-cyano-1-methyl-3-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl phenyl]guanidine in dog plasma by liquid-solid extraction and reversed-phase high-performance liquid chromatography.

A method for the determination of 2-cyano-1-methyl-3-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin- 3- yl)phenyl]guanidine (SK&F94836, 1) in plasma is presented. The method involves liquid-solid extraction of the drug by C18 cassettes, with subsequent elution by an AASP LC module for determination by HPLC with UV detection. The assay is rapid, precise, accurate, and specific. The between-day CV values over the concentration range 50-500 ng/mL are 4% or less; this rises to 8% at 25 ng/mL. The corresponding between-day bias is less than 1% over the same range of concentrations. The limit of quantification is 25 ng/mL and the assay can be used for measuring 1 in samples from preclinical studies following either oral or intravenous administration of the compound.

Practical computer validation for pharmaceutical laboratories.

Computer validation should address the scientific correctness of the application software, the business objectives of the organisation, and the concerns of regulatory agencies. It is a balance between a practical and cost effective system that must develop the confidence that the system is under control. This paper gives an overview of computer validation from the following perspectives. What is computer validation? Why can a computer system not be completely validated? Why and how should computer systems be validated? The principles outlined in this paper should be adapted to a specific system on a case by case basis depending on its scope and complexity.

Laboratory Information Management Systems in practice.

To maximize the benefits of a LIMS, the system must be integrated with the analytical instrumentation in the laboratory. This provides on-line data capture or transfer of results for matching with the corresponding sample records held within the database, which reduces transcription error checking and ensures data integrity. Furthermore, the LIMS must be integrated with existing corporate systems to ensure efficient use of resources and to avoid the development of parallel systems.

An update on laboratory information management systems.

The realization that a laboratory is an effective information generator within an organization has begun to influence the functions required of a laboratory information management system (LIMS): different laboratories require different functions. The trends in general computing such as open systems, adoption of relational database technology, and the use of more efficient development languages, are also impacting on the development of LIMS. These trends, plus the development of standards for both LIMS and analytical data interchange, will allow the development of systems that are quicker to implement, easier to maintain and meet the business need better.

An analysis of the Washington Conference Report on bioanalytical method validation.

The Washington Conference Report on bioanalytical method validation is analysed with respect to the requirements for precision and accuracy. It is shown that if the requirements are interpreted too literally, this could lead to disappointment in practice. A better approach is to separate the total measurement error into its constant (bias) and random (precision) components. To ensure that 95% of all methods fall within the acceptance interval of +/- 15% around the true value, would require, for example, the bias to be < or = 8% and the method precision to be < or = 8% relative standard deviation (RSD; n = 5).

The development of a strategy for the implementation of automation in a bioanalytical laboratory.

Laboratory automation is equipment, instrumentation, software and techniques that are classified into four groups: instrument automation; communications; data to information conversion; and information management. This new definition is necessary to understand the role that automation can play in achieving the aims and objectives of a laboratory within its organization. To undertake automation projects effectively, a laboratory automation strategy is outlined which requires an intimate knowledge of an organization and the target environment to implement individual automation projects.

Sample preparation for the HPLC analysis of drugs in biological fluids.

Sample preparation for the analysis of drugs in biological fluids consists of a number of unit operations that are used for (i) release of the drug from a conjugate or biological matrix; (ii) removal of endogenous compounds that could interfere with the assay; and (iii) techniques for liquid handling. The trends in sample preparation that have occurred over the past 10 years in the authors' laboratory are discussed. In general, there has been a move from the traditional liquid-liquid extraction to methods using bonded-silica which permit rapid throughput and efficient extraction. Automation of sample preparation has seen further gains in productivity; however, the present generation of equipment lack the control and communication systems that are essential for the development of the automated integrated laboratory of the future.

Laboratory Information Management Systems--part I. Concepts.

The purpose of this analytical survey is to give a summary of some of the main design features that can be incorporated into a Laboratory Information Management System (LIMS), in the context of the total automation of the laboratory. Additionally it will give potential purchasers of such systems some essential background knowledge and a summary of our experiences. The survey is presented in two parts: the first covers the features and the possible concepts that could be used in a LIMS system. This is followed in the second part by an outline of the stages of acquisition, validation and benefits of such a system. Together the two articles provide the information required to aid the design and installation of a LIMS. This first section deals with the possible features that a laboratory could include when contemplating the installation of such a system: the basic tools that are required for a LIMS, the database and the computer equipment are discussed. This is followed by the interfacing of analytical instruments and central versus distributed processor philosophy. The various screen formats available and the use of bar codes as a means of identifying samples and for rapid data entry into the computer system are discussed.

Laboratory Information Management Systems--part II. Implementation.

In this, the second of two articles on Laboratory Information Management Systems (LIMS), the stages of the acquisition of a system are discussed. First, the laboratory automation strategy is developed leading to the writing of the requirements specification sent to prospective suppliers. The next step, in conjunction with the chosen supplier, is to write the functional and systems specifications from which the LIMS will be tailored. Once installed the LIMS must be validated and in the event of hardware or software changes, should undergo partial or full re-validation. The education and training of users, and operational considerations are presented before concluding with possible developments of LIMS in the future.

Validation of bioanalytical chromatographic methods.

A strategy is discussed for the validation of chromatographic methods that are developed to quantify drugs in biological matrices. Both the validation terminology and the hypothesis testing are briefly reviewed. The emphasis is on the design of the experiments required to allow a reliable conclusion about acceptance or rejection of the bioanalytical method. In particular, it is explained how to evaluate the calibration line, devise experiments to estimate precision and bias and how to determine the stability of the analyte between the time of the sample collection and the analysis of the processed sample.

Liquid-solid sample preparation in drug analysis.

This article compares liquid-solid extraction (LSE) with the more conventional liquid-liquid extraction (LLE) for the preparation of biological samples for assay. The commercially available manual LSE methods, Sep-Pak and Bond Elut, as well as the automated instruments Prep and Analytichem Automated Sample Processor (AASP), are reviewed. Using examples from the literature and the authors' own experiences a practical guide is given to the advantages and disadvantages of LSE.

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 that assay should be monitored with quality control standards sent from the originating laboratory.

The analysis of SK&F 94120, a novel inotropic agent, and its four metabolites by isolation on C18 AASP cassettes followed by high-performance liquid chromatography.

A selective and specific assay for SK&F 94120 [5-(4-acetamidophenyl)pyrazin-2(1H)-one] and its four metabolites in plasma has been developed. The method incorporates a single liquid-solid extraction step using C18 Analytichem Automated Sample Processor (AASP) cassettes. This is followed by successive elutions of the solid phase with two mobile phases of increasing acetonitrile content, by an AASP liquid chromatography module. A mobile phase containing 10% acetonitrile elutes a glucuronide metabolite from the cartridge which is then chromatographed and quantified intact. A second mobile phase, containing 20% acetonitrile, is then used to elute the unchanged drug and the three other metabolites from the same cartridge. The assay shows good accuracy and precision (less than 10% for all analytes) and is able to determine SK&F 94120 and its metabolites in plasma at concentrations between 0.05 and 1.00 mg l(-1).

The distribution of amylobarbitone, butobarbitone, pentobarbitone and quinalbarbitone and the hydroxylated metabolites in man.

Fluid and tissue specimens collected from 30 subjects at autopsy have been assayed for their content of common sedative barbiturates and the corresponding hydroxylated metabolites by g.l.c. Where one barbiturate had been ingested an inverse relationship between lipid solubility of the drug and the distribution in fluids and tissues was observed. In most cases the liver, and in the remainder the spleen, contained the highest concentrations of barbiturate. Bile concentrations were often in excess of those in the corresponding liver. The metabolites of the four sedative barbiturates were usually present in lower amounts than the parent drugs in the fluids and tissues of most subjects but urine often contained much higher concentrations of metabolites--sometimes exceeding that of the parent drug in the liver. Administration of two or more barbiturates together did not appear to affect the distribution and metabolism of the individual drugs.

The human distribution of some barbiturate sedatives in combination with miscellaneous CNS-active drugs.

This paper presents 14 cases in which the distribution of barbiturates and the hydroxylated metabolites in combination with miscellaneous CNS-active drugs was studied. In 7 of these cases the other drug present was methadone, and in the remainder dihydrocodeine, morphine, propoxyphene, amitriptyline, meprobamate, cyclizine and dipipanone, diphenhydramine and methaqualine. Amitriptyline, methadone, cyclizine and dipipanone, methaqualone and diphenhydramine appeared to modify the distribution of amylorbarbitone and quinalbarbitone. Likewise, the barbituates seemed to alter the distribution of amitriptyline, propoxyphene and, in one instance, methadone.

Analytical methods validation: bioavailability, bioequivalence and pharmacokinetic studies. Conference report.

This is a summary report of the conference on Analytical Methods Validation: Bioavailability, Bioequivalence and Pharmacokinetic Studies. The conference was held from December 3 to 5, 1990 in the Washington, DC area and was sponsored by the American Association of Pharmaceutical Scientists, US Food and Drug Administration, Federation International Pharmaceutique, Health Protection Branch (Canada) and Association of Official Analytical Chemists. The purpose of the report is to represent our assessment of the major agreements and issues discussed at the conference. The report is also intended to provide guiding principles for validation of analytical methods employed in bioavailability, bioequivalence and pharmacokinetic studies in man and animals. The objectives of the conference were: 1. To reach a consensus on what should be required in analytical methods validation and the procedures to establish validation; 2. To determine processes of application of the validation procedures in the bioavailability, bioequivalence and pharmacokinetic studies; 3. To develop a report on analytical methods validation (which may be referred to in developing future formal guidelines). Acceptable standards for documenting and validating analytical methods with regard to processes, parameters or data treatments were discussed because of their importance in assessment of pharmacokinetic, bioavailability and bioequivalence studies. Other topics which were considered essential in the conduct of pharmacokinetic studies or in establishing bioequivalency criteria, including measurement of drug metabolites and stereoselective determinations, were also deliberated.

Developing a strategy for a regulated electronic bioanalytical laboratory.

This perspective article considers the strategy, design and implementation of an electronic bioanalytical laboratory working to GLP and/or GCP regulations. There are a range of available automated systems and laboratory informatics that could be implemented and integrated to make an electronic laboratory. However, which are the appropriate ones to select and what is realistic and cost-effective for an individual laboratory? The answer is to develop an overall automation strategy that is updated periodically after each system or application has been implemented to assess if the strategy is still valid or needs to be changed. As many laboratory informatics applications have functional overlap or convergence, for example, Laboratory Information Management System, Electronic Laboratory Notebook, and Instrument and Chromatography Data Systems, the decision of which application performs a specific task needs to be carefully considered in the overall strategy. Ensuring data integrity and regulatory compliance, especially in light of a number of recent falsification cases, is a mandatory consideration for the overall strategy for an electronic bioanalytical laboratory submitting data to regulatory authorities.

An evolutionary view of chromatography data systems used in bioanalysis.

This is a personal view of how chromatographic peak measurement and analyte quantification for bioanalysis have evolved from the manual methods of 1970 to the electronic working possible in 2010. In four decades there have been major changes from a simple chart recorder output (that was interpreted and quantified manually) through simple automation of peak measurement, calculation of standard curves and quality control values and instrument control to the networked chromatography data systems of today that are capable of interfacing with Laboratory Information Management Systems and other IT applications. The incorporation of electronic signatures to meet regulatory requirements offers a great opportunity for business improvement and electronic working.