Monday, 4 February 2013

Source and effect of Impurities in Pharmaceuticals

We know that the substance that are used in pharmaceutical field must be pure so that they can be used safely. But it is very difficult to obtain an almost pure substance. We find different substance and chemicals with varying degree of purity. So today we are going to discuss different sources of impurities and some of the effect of impurities on pharmaceuticals.

Sources of impurities.
  • Raw materials employed in manufacture.
  • Method or the process used in manufacture.
  • Chemical processes and the plant materials employed in the processes.
  • Storage conditions.
  • Decomposition.
Effect of Impurities: We know that almost pure substances are difficult to get and some amount of impurity is always present in the material. So the impurities which are present in the substances may have the following effects.
  • Impurities may bring about incompatibility with other substances.
  • Impurities may lower the shelf life of the substances.
  • Impurities may cause difficulties during formulations and use of the substances.
  • Sometimes Impurities changes the physical and chemical properties of the substances.
  • Therapeutic effect can be decreased.
  • Shows toxic effect after a certain period.
  • Injurious when present above certain limits.
  • It may change odour, colour, taste of the substance.
To prevent these impurities many test such as limit test are carried out to lower the impurities to make the pharmaceuticals more safe.