Simultaneous spectrophotometric determination of ampicillin and penicillin in human plasma using multivariate calibration

An analytical methodology based on spectrophotometric and partial least squares (PLS) algorithm for thesimultaneous determination of ampicillin and penicillin in human plasma was developed and validated. Themultivariate model was developed as a binary calibration model and it was built and validated with anindependent set of synthesis and real samples in presence of matrix. It is shown how a developed techniquefor signal filtering, orthogonal signal correction (OSC), can be applied in multivariate calibration to enhancepredictive power. The experimental calibration matrix was constructed with 25 samples. The concentrationranges considered were 1.0-40.0 and 0.5-20.0 μg mL-1 for ampicillin and penicillin, respectively. Thisprocedure allows the simultaneous determination of ampicillin and penicillin in synthetic and human plasmagood reliability of the determination was proved. The results obtained by the OSC-PLS and HPLC werestatistically compared. Very similar values were found by two methods. No time consuming pretreatmentwas needed and this method also provides rapid, accurate and economical analysis of these drugs.