A five-batch analysis is a study that measures the active content and every significant impurity in five production batches of a technical grade active. Regulators use it to see what the plant really makes, batch after batch, and to set the specification the product will be held to.
It is a core part of almost every agrochemical registration dossier. For a generic source, it is also the starting point for the equivalence check against a reference source.
What the study contains
- It reports five separate batches, made at commercial scale on the line that will supply the market.
- It gives the active ingredient content of each batch, measured by a validated method.
- It identifies and measures each impurity, usually down to a set reporting threshold. In EU practice, impurities at or above 1 g/kg must normally be identified and quantified.
- It measures toxicologically relevant impurities even below that threshold, with methods sensitive enough to find them.
- It shows a mass balance, adding active and impurities, which should come close to the whole sample.
- It records batch numbers, production dates, the site and the validated methods used.
Who runs the study
The manufacturer usually pays for the study and owns it. It sends retained samples from five batches to an analytical lab, often its own GLP-certified lab or an independent one.
Many regulators require the study to be done under Good Laboratory Practice. See what GLP is and how to check an Indian lab.
Why regulators want it
A single certificate of analysis shows one batch on one day. Five batches show whether the process is consistent. Regulators set the minimum purity and the maximum level of each relevant impurity from this data, so the study shapes the specification you will live with.
For generics, the impurity profile in the five-batch analysis is compared with the reference profile. New or higher impurities can mean further toxicology data, or a refusal. Our guide to equivalence testing explains this step.
What to check as a buyer
Treat the study as a description of what you should receive, not a sales document. Ask these questions.
- Were the five batches made at the site and by the process that will make your order?
- How old are the batches? Many regulators expect recent production, so check your regulator's rules on age.
- Was the lab GLP-certified for this type of study when it did the work?
- Has the process or a key raw material changed since the study? If so, the profile may have changed too.
- Do your incoming lots match the study's impurity profile, not just its purity?
Using it after registration
Once a product is registered, every lot you import should meet the specification built from the study. Test the key impurities on incoming lots, not only active content. Agree in your contract that the supplier must tell you before it changes its route, its raw material source or its site, because any of these can change the profile.
Next step
We check five-batch studies against the site and process that will supply you, and have lots tested for the impurities that matter. Book a free sourcing review to plan your registration source.