Sources of Impurities in Pharmaceutical Subsstances

The root of impurities in drugs is from various sources and phases of the synthetic process and the development of pharmaceutical dosage forms. The bulk of the contaminants are characteristics of the synthetic manufacturing method. There are numerous possibilities for synthesizing a drug; the identical product of different sources may give growth to different impurities.

The impurities in pharmaceutical effects can be linker to a variety of sources, including the formulation process or interactions with the packaging of the numerous impurities that can be detects in medication effects, in addition to the drug import or inert ingredients use to create a medicinal product. The impurities formation may occur either in APIs, formulation developments, or during formulation. The sources of impurities may be from the middle step or the synthesis route or may be due to the warehouse etc.

The origin of contaminants in drugs comes from different sources and phases of the synthetic method and preparation of pharmaceutical dosage conditions. Most of the impurities are characteristics of the synthetic route of the manufacturing method. Therefore, several options exist for synthesizing a drug; the identical effect from different sources may give rise to other impurities.

According to the ICH, organic, inorganic, and residual solvents are impurities. Organic impurities may arise from creating materials, by-products, synthetic intermediates, and degradation by-products. Inorganic impurities may be emanate from the manufacturing process and are generally known and identify as reagents, ligands, inorganic salts, heavy metals, catalysts, filter aids, charcoal, etc. Eventually, residual solvents are the impurities present with solvents. The number of inorganic contaminants and residual solvents of the above three types is fixed.

According to the ICH, impurities are marked as organic impurities, inorganic pollutants, and residual solvents.

By-products, synthetic intermediaries, and degradation by-products all have the potential to produce organic contaminants. Inorganic impurities that are commonly known and recognised as reagents, ligands, inorganic salts, heavy metals, catalysts, filter aids, charcoal, etc. may be created during the production process. Solvent impurities are called residual solvents.

Among the three overhead types, there are a finite number of leftover solvents and inorganic pollutants. These can be easily distinguished, and information about their toxicity and physiological effects is widely available. Because of this, the ICH guidelines and pharmacopeial limits can ensure that the negative effects of these impurities do not increase the toxicity or effects of the drug substances.

The situation is different with the natural impurities. Drugs designed by multi-step synthesis results in multiple impurities. Their number and the type of structures are almost limitless and highly dependent on the route and reaction requirements of the synthesis and several other factors such as the purity of the starting fabric, process of isolation, purification, storage requirements, etc. 

In addition, toxicity is confidential or needs to be more efficiently predictable. For this reason, the ICH guidelines set a threshold above which identifying the impurity is essential.

(A) Sources of organic impurities:

  • Impurities stemming from drug substance synthetic methods
  • Beginning materials and intermediates
  • Impurities in the opening materials
  • Reagents, ligands, and catalysts
  • By-products of the synthesis
  • Products of over-reaction
  • Products of side reactions
  • Impurities were arising from the degradation of the drug substance.

(B) Enantiomeric impurities:

Most therapeutic chiral drugs utilized as pure enantiomers are natural products. The high level of enantioselectivity of their biosynthesis eliminates the possibility of enantiomeric impurities. If the purified enantiomer of the racemates, typically sold in synthetic chiral drugs, is released, the antipode is an impurity. The reason for its presence can be either the inadequate enantioselectivity of the syntheses or the meager resolution of the enantiomers of the racemate. 

Life chem pharma is a manufacturer of drug intermediates. At life chem pharma, we focus on the quality of pharmaceutical intermediates and fine chemicals through regular quality audits. Quality runs across all our departments, from early-stage development to document control and manufacturing to validation. Irrespective of position, our people are passionate about delivering manufacturing superiority.

Effect of Impurities: 

We know that almost all pure substances are difficult to get, and some impurity is invariably present in the material. So, the impurities present in the substances may have the following effects.

  • Impurities may get into conflict with other substances.
  • Impurities may reduce the shelf life of the substances.
  • Impurities may cause complications during the formulation and use of the substances.
  • Sometimes, Impurities alter the physical and chemical properties of the substances.
  • The therapeutic effect can be decreased.
  • Shows harmful impact after a certain period.
  • when present in excess of specific thresholds, harmful.
  • It may change the substance’s odor, color, and taste.


Life chem pharma is one of the foremost manufacturers and exporters of Advanced Pharmaceutical Drug Intermediates.

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