The USP impurities method for quetiapine fumarate was successfully transferred globally on the Arc HPLC System and met all system suitability requirements. While variation in results was observed across the sites, the investigations showed that the cause for each outlier varied. Some variation was attributed to sample preparation, while others were due to instrument configuration differences. However, having a sound understanding of the effects of the system configuration and the method on the results allowed the sending lab to take a systematic approach to investigating any outliers. Within the study described general steps included:
1. Identifying the outlier results and potential contributions to result
2. Reviewing system configurations, including detector and tubing ID
3. Reviewing sample and mobile phase preparations procedures analyst-to-analyst
This approach can also be used to investigate any out of spec results. This study showed that understanding the risk of the method and implementing control strategies can provide a successful method transfer.