Accuracy of the method was determined by investigating control solutions at three concentration levels of carvrdilol (50,120 and 180 ng mL1) which was defined by recovery (R %).
Triplicate extractions of the control solutions were performed at each concentration level and on three consecutive days to determine the intraday and inter-day precision, which was expressed in terms of relative standard deviation (RSD, %) of the recovery.
Ultimately, applicability of this procedure was tested on real samples by analyzing carvedilol in plasma of a volunteer patient.