Types of Impurities in Pharmaceuticals

The impurities in pharmaceuticals are organic or inorganic material, or residual solvents other than the drug substances or ingredients that arise out of synthesis or unwanted chemicals that remain with the active pharmaceutical ingredients (APIs) or develop during formulation or upon aging of both API and formulation.

Pharmaceutical Impurities can be of three types:

1. Impurities closely related to the product and coming from the chemical or from the biosynthetic route itself

2. Impurities formed due to spontaneous decomposition of the drug during the storage or on exposure to extreme conditions,

3.The precursors which may be present in the final product as impurities.

According to ICH guidelines, impurities in the drug substance produced by chemical synthesis can broadly be classified into the following three categories

Organic Impurities (Process and Drug related)

The actual and potential impurities most likely to arise during the synthesis, purification, and storage of the drug substance. Organic volatile impurities are residual solvents that are used in and are produced during the synthesis of drug substances, or in excipients used in the production of drug formulations