Most Invalidated OOS citing laboratory error as a root cause may fall into Inconclusive OOS. For example, consider there were several samples in a chromatographic sequence for an assay analysis and only one or two samples fails in Assay. If this OOS is being invalidated with probable root cause of laboratory error like air bubble in the system or analyst error in sample preparation, the root cause is Inconclusive. Question is why only specific samples are OOS in the same sequence when other samples comply. On the otherhand, an OOS with laboratory error as root cause where column performance has deteriorated giving poor peak shape and a series of samples have given poor peak shape and OOS results, can be considered Conclusive. The former OOS should be supported by manufacturing investigation to confirm no manufacturing issues caused OOS, and well justified scientific rationale for root cause and hypothesis tests for invalidating the OOS. The latter, where deterioration of column performance results in OOS do not call for a manufacturing investigation.
Most Invalidated OOS citing laboratory error as a root cause may fall into Inconclusive OOS. For example, consider there were several samples in a chromatographic sequence for an assay analysis and only one or two samples fails in Assay. If this OOS is being invalidated with probable root cause of laboratory error like air bubble in the system or analyst error in sample preparation, the root cause is Inconclusive. Question is why only specific samples are OOS in the same sequence when other samples comply. On the otherhand, an OOS with laboratory error as root cause where column performance has deteriorated giving poor peak shape and a series of samples have given poor peak shape and OOS results, can be considered Conclusive. The former OOS should be supported by manufacturing investigation to confirm no manufacturing issues caused OOS, and well justified scientific rationale for root cause and hypothesis tests for invalidating the OOS. The latter, where deterioration of column performance results in OOS do not call for a manufacturing investigation.
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