Degradation products defined

Indicate the stability-indicating method(s) used to quantitate the drug substance, its impurities, and its degradation products. Define the possible deg-... 

The dye has been degraded by a fusion with caustic potash and the degradation products identified as various o-anilinyl mercaptans. They were identified and characterized by condensation with monochloroacetic acid to give the thioglycohc acids which, on acidification, were converted to well-defined crystalline lactams (2—4) together with a small amount of ji)-aminobenzoic acid. 

Related substances are defined as known impurities which may be identified or unidentified (Technical Guide for the Elaboration of Monographs 1996). They include intermediates and by-products from a synthetically produced organic substance impurities, co-extracted from a natural product and degradation product of the substance. 

To select and define the target analytes for the residue analysis of crops in a field trial, applicants should consider metabolites/degradation products of the test materials by conducting plant and animal metabolism studies and by assessing toxicity of the metabolites/degradation products. 

Almost 10% of the TRR level of the metabolites/degradation products will be selected and defined as the analytes for residue analysis. 

In the common vernacular, the terms specificity and selectivity are often interchangeably used. More properly, a method is said to be specific if it provides a response for only a single analyte, while the term selective means that the method provides responses for a number of chemical entities that may be distinguished from each other. Selectivity also implies the ability to separate the analyte from degradation products, metabolites, and coadministrated drugs [12]. USP 28 [1] defines specificity as the ability to assess the analyte unequivocally in the presence of other components such as impurities, degradation products, and the matrix. IUPAC and AOAC have preferred the use of the term selectivity than specificity for methods that are completely selective, while USP, ICH, and FDA used the term specificity . Due to the very number of limited methods that respond to only one analyte, the term selectivity is usually more suitable, and this usage will be used in this work. 

Sample analyses should be performed in a laboratory certified for the necessary procedures, and they must be able to meet detection limits in the expected media and chemical mixtures. Some analyses are specified by existing EPA protocols, but this is not the case for agent and agent degradation products. Both the closure plan and the postclosure plan should precisely define the protocols to be used for these classes of compounds, including precision and accuracy for expected contaminants. 

Apart from the pure process-driven requirements of the disintegration within a defined time span and the proof of ultimate biodegradability, it is necessary to make sure that there is no negative impact of degradation products or intermediates of the degradation process on the environment. Adequate information has to be provided for a comprehensive assessment of environmental and toxicological safety. 

Better test methods should be developed to define and ultimately to model and predict the byproducts and degradation products associated with production and use of materials. Basic studies of biochemical effects and of the impact of various chemicals and other adverse effects on the biochemistry of sensitive plant and animal species should be strongly supported. 

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