Drug Substance

The solubility of a substance becomes especially important in the pharmaceutical field because it often represents a major factor that controls the bioavailability of a drug substance. Moreover, solubility and solubility-related properties can also provide important information regarding the structure of drug substances, and in their range of possible intermolecular interactions. For these reasons, a comprehensive knowledge of solubility phenomena permits pharmaceutical scientists to develop an optimal understanding of a drug substance, to determine the ultimate form of the drug substance, and to yield information essential to the development and processing of its dosage forms.

The current practice of characterization and control of impurities in pharmaceuticals is reviewed with emphasis on issues specific to the generic industry. This review includes an overview of FDA, ICH, TGA, TPD and EMEA guidelines related to impurities in Drug Substance and Drug Products. This introduces the identification, characterization and qualification procedures for ANDAs and approaches to the establishment of acceptance criteria for both drug substance and drug product and significance of analytical methods in total process.