Partial Least Square and Parallel Factor Analysis Methods Applied for Spectrophotometric Determination of Cefixime in Pharmaceutical Formulations and Biological Fluids

In this study, the direct determination of cefixime as an anti-bacterial agent, in pharmaceutical formulations, urine and human blood plasma was conducted based on spectrophotometric measurements using parallel factor analysis (parafac) and partial least squares (pls). the calibration set was composed of fourteen solutions in the range of 0.50- 9.00 µg ml^-1. pls models were calculated at each ph applied to determine a set of synthetic cefixime solutions. the best model was acquired at ph 1.02 (pls-ph 1.02). the ability of the method for the analysis of real samples was considered by determination of cefixime in pharmaceutical preparations, urine and plasma with satisfactory results. the calculated model with parafac showed good prediction capability with root mean square error of prediction (rmsep) of 0.12 for cefixime. the acid dissociation constants (pk_a) of cefixime play a fundamental role in themechanism of activity of cefixime. the pk_a of cefixime were estimated by datan program using the corresponding absorption spectra-ph data. the calculated p_ka values of cefixime were 1.89 and 3.80 for pk_a1 and pk_a2