Impurities in pharmaceutical substances PDF Note Free Download For Pharmacy Students.
An impurity as defined by the ICH (The International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use) guidelines is “any component of the medicinal product which is not the chemical entity defined as the active substance or an excipient in the product”. Analytical methods for impurities estimation should be stability indicating to monitor the stability of pharmaceutical dosage forms during the investigational phase of drug development, and once the drug is marketed, the ongoing stability studies must be conducted/ performed. The purpose of stability testing is to provide evidence on how the quality of a drug substance or drug product varies with time under the influence of a variety of environmental factors such as temperature, humidity and light, enables to establish a retest period/shelf life for a drug substance and a recommended storage condition. Methods can be developed which measure the amount of drug remaining, the amount of drug lost (or the appearance of degradation products), or both. The development of these methods for
pharmaceuticals can be approached from several avenues. Related components, related substances, and related impurities are synonyms for the term impurities; the use of above terms at different phrases means one and the same (i.e. impurities).