What is an impurity profile?
A description of the identified and unidentified impurities present in a drug substance. 3. What are the different types of impurities? Organic impurities (Process and Drug-Related) Inorganic impurities (Heavy metels, Catalysts, Inorganic salts) Residual Solvents. Others impurities such as microbial flora, pyrogens, particulate matter. 4. What are the sources of impurities? • Starting materials • By-Products (from the route of synthesis) • Intermediates • Degradation products • Reagents, Ligands and Catalysts • Solvents • Unwanted enantiomeric form (in case of optically active compound) • Process aids such as: Filter aids, Charcoal, Filter papers • Unwanted polymorphic forms (in certain drugs like Ranitidine Form I) 5. What are the methods for detecting of impurities? • Thin Layer Chromatography • Gas Chromatography • High Pressure Liquid Chromatography • Column Chromatography • Nonaqueous Titration • Acid-Base Titration • Optical rotation • Melting point • Refractive Index • Atomic Ab
