Stability testing scientific principles

Environmental analytical association Ecoanalytica produce standai d samples during last 12 years. Two topics will be discussed. The first is the principles of development of staictures and maintenance of quality of standai d samples. The organization of manufacture and maintenance of their stability ai e considered too in the report. Besides them authors consider scientifically-methodical aspects of preparation of samples for experimental check of technical competence of analytical laboratories and also samples for interlaboratory tests. 

The underlying principle of GLP requires that the retention of records, other documentation, samples and specimens should provide, wherever possible, the means for full study reconstruction. Thus, it follows logically that also samples from each batch of test and reference item should be collected and retained. In this way it can be ensured that any questions regarding the quality, purity, stability and identity of the test item, that might turn up during the Quality Assurance audit or the scientific assessment of the study, could be resolved by an independent analysis of the reserve sample, without necessitating the repetition of the study itself in case of major doubts about the test item. The requirement that a sample for analytical purposes from each batch of test item should be retained would therefore not seem to pose major problems of interpretation and implementation. 

Allergen inhalation tests are primarily a research tool. For this reason, the principles of standardization have been developed to try and assure the best possible intraindividual reproducibility. The principles of standardization outlined below are based on both scientific and empirical concepts. Standardization encompasses technical aspects (aerosol generation, inhalation, measurement of response) and nontechnical or subject-related aspects, the latter designed to assure patient stability. 

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