Warning Letter of the Week: integration inhibition edition

A friendly missive from the Center for Drug Research and Evaluation to the Director and President of Operations of Divi’s Laboratories Ltd. (Unit II): 

1.      Failure to ensure that test procedures are scientifically sound and appropriate to ensure that your API conform to established standards of quality and/or purity.
Our investigators observed that the software you use to conduct high performance liquid chromatography (HPLC) analyses of API for unknown impurities is configured to permit extensive use of the “inhibit integration” function without scientific justification.  For example, our investigator reviewed the integration parameters you used for HPLC identification of impurities in release testing for [redacted]. These parameters demonstrated that your software was set to inhibit peak integration at four different time periods throughout the analysis. Similarly, in the impurities release testing you performed for [redacted], your HPLC parameters were set to inhibit integration at four different time periods throughout the analysis.

Inhibiting integration at various points during release testing for commercial batches is not scientifically justified. It can mask identification and quantitation of impurities in your API, which may result in releasing API that do not conform to specifications.

I didn't know you could do that - the things you learn....