EMA provides detailed procedure for evaluation of
matrix effect. At least six lots of matrix should be used
including hemolyzed and hyperlipidaemic and, if applicable,
from special populations such as renally or hepatically
impaired. For each analyte and internal standard, matrixfactor (described in later sections) should be calculated at
analyte concentration of maximum three times of LLOQ.
In addition, IS normalized matrix factor should also be
calculated for all six batches and %CV of IS normalized
matrix factor should not exceed 15. However, a more
stringent approach has also been suggested in case of
online sample preparation. In this procedure, six batches of
matrix should be spiked in triplicates with analyte concentration
of not more than three times of LLOQ and
should be analyzed against a freshly prepared calibration
curve. The overall %nominal and %CV of back calculated
concentration should not exceed 15. In addition, the
%nominal for individual batch of matrix should not exceed
20 in case of insignificant matrix effects.