You need to initiate an investigation into this discrepancy. The process for doing this is covered in Learnaboutgmp’s eLearning course number ELM 108 Laboratory Investigations and Deviations.
You need to ensure the method you use is fully validated. If the method is validated and correctly followed there is no reason way the value obtained should not reflect the content of active in the product.
The investigation need to determine that no mistakes were made during the analysis. Before you can conclude an error was made during testing there must be convincing evidence. Conclusions of analyst error with out adequate convincing evidence to support it often results in an audit observation.
Dr David Trew
David Trew Consulting Ltd
Consultancy for chemistry based businesses
The comments entered here are not intended to constitute any form of consultancy