Blog Date 23 February, 2026

What Should Manufacturers Know About Nitrosamine Limits?

Manufacturers in the pharmaceutical industry play a very important role in keeping trace amounts of impurities that could put patients' safety at risk. One type of impurity, called "Nitrosamines," has gotten a lot of attention around the world because it may cause cancer. The European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA) are two examples of authorities that now want stricter monitoring and adherence to set acceptable intake (AI) levels. Not meeting these standards puts the health of the public at risk and also puts a company's product approvals and reputation at risk.

It's important for any drug manufacturer, especially those working with compounds like Lidocaine and Rizatriptan, to know how Nitrosamine impurities form, what rules apply and how to find them.

Understanding Nitrosamine Impurities in Pharmaceuticals

Nitrosamines are chemicals that have a nitroso group and an amine group. They can happen during chemical synthesis, degradation or storage but not on purpose. This is especially true when the conditions are acidic or hot. Because they are likely to cause cancer in humans, regulators set strict AI limits to make sure that patients are not exposed to too much of them over their lifetime.

Several recalls have happened in the pharmaceutical industry because of unexpected Nitrosamine contamination. So, it's no longer optional to do proactive risk assessments and use proven analytical methods.

Why N-Nitroso N-Desethyl Lidocaine Demands Attention?

Subcategory: Lidocaine

Lidocaine, a commonly employed local anaesthetic, is linked to the development of a Nitrosamine impurity identified as:

This impurity can form when the desethylated metabolite of Lidocaine breaks down or reacts with nitrosating agents. It is important to look at the whole process lifecycle, from API synthesis to formulation, to lower risks, even though the formation pathway changes depending on how it is made. Controlling leftover amines and nitrites and making sure the best storage conditions are in place to stop formation should be part of risk management.

Spotlight on Nitrosamine Risk: Rizatriptan Impurity You Can’t Ignore

Rizatriptan, a medication used for treating migraines, is another drug that requires attention. It may potentially generate:

Even though there isn't a formal CAS number yet, industry evaluations have already flagged the impurity. Manufacturers should still take this risk seriously and use the same strict rules that they use for other Nitrosamine contaminants. Until specific AI limits are put in place by the government, it is wise to follow interim limits of 18 to 26.5 ng/day, depending on where you live.

Regulatory Guidelines and Acceptable Intake (AI) Limits

Global organisations have set clear rules for Nitrosamine limits:

  • FDA: Introduced a Carcinogenic Potency Categorisation Approach (CPCA) based on the structure–activity relationship (SAR). It gives AI values by looking at how similar the structure is to known carcinogens.
  • EMA and Health Canada: Set AI limits based on either compound-specific or default potency data. If there isn't much data, they usually set conservative levels at around 18 ng/day.

When there isn't enough toxicological data, default limits are used as placeholders until more specific information about the substance can be found. The goal is to keep exposure low enough so that the theoretical risk of getting cancer stays below 1 in 100,000 over a lifetime.

Quality Control, Risk Assessment and Testing

Manufacturers must do the following to stay in compliance:

  • Do a full risk assessment: Find all the things that could cause Nitrosamine to form, such as reactants, solvents, excipients, packaging and storage.
  • Use validated detection methods: GC-MS and LC-MS/MS are examples of methods that can accurately and sensitively measure very small amounts of impurities.
  • Update controls and documentation: Make sure that regulatory filings show the most recent assessments of impurities and steps taken to reduce them.

Trusted Compliance with Chemicea

It doesn't have to be hard to figure out how to control Nitrosamine. Chemicea has the knowledge and tools to help manufacturers meet strict global standards. The company has a 7000 sq. ft. R&D facility and is certified by ISO and GMP. It serves more than 2000+ customers in more than 35+ countries. Chemicea is your trusted partner for making sure your products meet all quality, safety and regulatory standards. They specialise in pharmaceutical reference standards.

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