Assays, tests, assessment methods

Recent guidelines entitled Non-clinical Local Tolerance Testing of Medicinal Product from the CPMP refer to the murine local l)unph node assay as a method for the assessment of the induction phase of skin sensitisation. This method measures the ability of compoimds to induce proliferative responses in skin-draining lymph nodes. This method uses fewer animals than alternative in vivo methods and reduces the trauma to which animals are potentially subjected. ... 

Sugiyama, M., Itagaki, H. and Kato, S. (1994) Photohemolysis test and yeast growth inhibition assay to assess phototoxic potential of chemicals, in Alternative Methods in Toxicology (eds A. Rougier, A.M. Goldberg and H.I. Maibach), Mary Arm Liebert, Inc., NY, 10, pp. 213-221. 

Use in the production of vaccines As assay organisms to determine antibiotic, vitamin and amino acid concentrations Quality control of immunological products Assay methods Sterilization methods Sterilization monitoring and validation procedures Sterility testing Assessment and calculation of sterility assurance Aseptic manufacture... 

It is important that the evaluation of a field-portable assay method include performance data generated by personnel unskilled in immunoassay. The importance of an on-site demonstration is to test the method under actual field conditions. This ruggedness testing will determine the necessary precautions needed during field use. The precision, accuracy and bias obtained in the field will be compared to data obtained in the laboratory to fairly assess performance of the method obtained by unskilled personnel. 

Unlike direct reference assays, indirect index methods use two separate tests to estimate the free hormone concentration a total serum T4 (or T3) measurement and an assessment of either the serum TBG concentration or the fraction of T4 (or T3) that is free m serum the latter is traditionally derived using equilibrium tracer dialysis or T uptake methods. Results of these tests are then combined mathematically to give estimates of the free hormone concentration. Indirect index-based methods have essentially fallen out of favor in deference to the direct immunoassay methods. 

Cardiac SP in vivo methods primarily use conscious telemetered animals to assess the effects of the test item on the cardiovascular system. Variables that are recorded in the dog include blood pressure, heart rate and ECG (see Authier et al. 2015). Complementary studies, usually non-GLP in namre, include a number of in vitro assays that have been well characterised with utility in the safety profiling of an NCE. These assays include assessment of drug effects in the isolated guinea pig right atrium preparation, rabbit Purkmje fibre preparation, the isolated Langendorff heart and the isolated wedge preparation. Each assay will be briefly discussed. 

The purpose of method validation is to demonstrate that an analytical method is suitable for its intended purpose and, for a quantative method, provides a reasonable estimate of the true value of the sample tested. Appropriate performance characteristics, such as accuracy and precision, must be demonstrated before making decisions based on test data. Method validation involves assessing method performance against predefined criteria, established based on the sample specifications and the type of measurement to be performed, for example, assay, identification, or limit test. A rigorous assessment of method performance versus predefined criteria provides assurance that the method will consistently provide a fit for purpose performance. Method characteristics to be evaluated during method validation are described by several guidelines [1,2] some of which are shown in Tables 3.1 and 3.2. 

It is tempting to classify all in vivo techniques as risk-assessment methods. For example, host-mediated-type studies have been incorrectly assumed to be more applicable to risk assessment than related in vitro studies. This is not necessarily true, since the genotoxic end points are still measured by in vitro test systems coupled with the animal host, and therefore the data are still valid only to detect potential. Attributing greater relevance to such tests may result in erroneous conclusions regarding safety or risk. Actually, there are very few practical risk-assessment assays available to evaluate genotoxicity, and our ability to extrapolate results from these to humans is uncertain, since evidence demonstrating mutation induction in humans is technically not possible. 

Tables 4 and 5 summarize the general applications of mutagenesis assays. Phase I involves utilization of the assays as primary detection, prioritization, and risk-assessment methods, and Phase II illustrates their application as ancillary tests for quality control and occupational monitoring.

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