- Impurities in pharmaceuticals are the unwanted chemicals that remain with the active pharmaceutical ingredients (APIs), or develop during formulation, or upon aging of both API and formulated APIs to medicines.
Impurities are substances inside a confined amount of liquid, gas, or solid, which differ from the chemical composition of the material or compound.
Impurities are either naturally occurring or added during synthesis of a chemical or commercial product.
Impurities are classified as :
- Organic impurities
- Inorganic impurities
- Residual Solvents
Organic impurities may arise during the manufacturing process and/or storage of the new drug substance. They may be identified or unidentified, volatile or non-volatile and include:
- Starting materials
- Degradation Products
- Reagents, Ligands and catalyst
Inorganic impurities may derive from the manufacturing process. They are normally known and identified and include:
- Reagents, Ligands and Catalysts
- Heavy Metals
- Inorganic Salts
- Other materials (e.g. Filter Aids, Charcoal etc.)