Specified vs. Unspecified Impurities in Pharmaceuticals
Introduction and Background: Specified and Unspecified Impurities
Specified and Unspecified; The Specified and Unspecified Impurities play a vital role in related substance or impurities profile specification of any pharmaceutical. Both Specified and Unspecified Impurities refer to the identification, control, and regulation of these impurities during drug development and manufacturing.
Specified and Unspecified Impurities
Specified Impurities:
- These are impurities that have been identified and characterized during the pharmaceutical development using different analytical techniques like FTIR, NMR, Mass, HPLC, GC and KF/LOD
- Their chemical structure, origin, and potency are known.
- They are typically listed and quantified in the drug’s specification.
- Regulatory guidelines often set limits for these impurities to ensure that they are present within safe, acceptable levels.
- Examples include process related impurities, degradation products, residual solvents, or by-products from synthesis, which are well-characterized.
Unspecified Impurities:
- These are impurities that are not identified or characterized during pharmaceutical development.
- Their chemical structure and origin are unknown.
- They may be detected during testing, but their structure is not known.
- These impurities come under related substances or impurities profile tests.
- Regulatory agencies may set limits on unspecified impurities, typically based on safety concerns or the potential for these substances to impact the drug’s quality, safety, and efficacy.
Specified vs. Unspecified Impurities: Key Differences:
- Identification:
- Specified impurities are identified and known.
- Unspecified impurities are unknown and not characterized.
- Regulation:
- Specified impurities have known limits and are monitored during production.
- Unspecified impurities are controlled with limit NMT (not more than 0.10%)
- Safety:
- Specified impurities are typically controlled based on known toxicological data.
- Unspecified impurities may pose unknown risks, which is why limits for these are often set conservatively.
Conclusion
The key difference lies in the level of characterization and regulation of the impurities. You may also want to check out other articles on my blog such as:
- Analytical method development and validation
- How to control Genotoxic Chemicals?
- What is the difference between Genotoxicity and mutagenicity?
- Impurities Control Strategies in Pharmaceuticals
FAQs
What is an unknown impurity?
The impurity whose structure is not known is called an unknown impurity
What is the limit for unknown impurity in ICH?
The limit of unknown impurities is 0.10%
What is unspecified impurity?
The known or unknown impurity which is not part of the specification is called unspecified impurity.
What is the difference between specified and unspecified impurities?
Specified impurity comes under known impurity in the specification whereas unspecified impurity comes under unknown impurity in the specification
How to decide unknown impurity limit?
The limit of unknown impurity is not more than 0.10%
What is the ICH limit for unspecified impurities?
The ICH limit for unspecified impurity is not more than 0.10%