Saturday, October 20, 2018

Different Types of Impurities in Pharmaceutical Substances

A drug or excipients are the source of Impurities in Drug products and also from the packaging and process steps impurities are come. However, many impurities can be identified in any drug product sample; there are fewer impurities which have the effect on performance or stability in the dosage form, in common mainly harmful impurities are small molecules, especially in the solid dose where inadequate mobility prevents reactions of large molecules. 
For the majority of drugs, reactive species have water, metals, and peroxides; these are the impurities that effect on the dosage forms throughout physical changes and chemical reactions in the system. The drug substance purity depends on reducing the level of impurity, not just for release; it should be maintained lower levels throughout the shelf life of the drug substance.
Impurities can be classified into the following categories when the drug substance is chemically synthesized.

  • Organic impurities 
  • Inorganic impurities 
  • Residual solvents 
  • Foreign Substances and other Impurities
  • Toxic Impurities
  • Ordinary Impurities
Therefore, it is necessary to evaluate the impurities using different instruments and techniques, before allocating the purity value to the drug substance.

No comments:

Post a Comment