Abstract

DETERMINATION OF SIMVASTATIN AND GEFITINIB IN BINARY MIXTURE USING SPECTROPHOTOMETRIC, CHEMOMETRIC - ASSISTED SPECTROPHOTOMETRIC AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHODS

Chilka R. Patel*, Kirangi B. Desai, Krishna A. Joshi, Prasanna K. Pradhan, Suddhasatya Dey, Umesh M. Upadhyay

ABSTRACT

Four methods were developed for simultaneous determination of simvastatin and gefitinib without previous separation. In the first method both drugs were determined using first derivative UV spectrophotometry, with zero crossing measurement at 237.2 and 348 nm for simvastatin and gefitinib, respectively. The second method depends on first derivative of the ratios spectra by measurements of the amplitudes at 240.6nm for simvastatin and 235.8 nm for gefitinib. Calibration graphs are established in the range of 1-3.5 μg/ml and 6-21 μg/ml for simvastatin and gefitinib, respectively. The third method describes the use of multivariate spectrophotometric calibration for the simultaneous determination of the analyzed binary mixture where the resolution is accomplished by using partial least squares (PLS), Classical least square (CLS), Inverse least square (ILS), Principal component regression (PCR) regression analysis.. In the fourth method (HPLC), a reversed-phase column and a mobile phase of Acetonitrile: Methanol: Water (60: 30: 10 v/v/v) at 1 ml/min flow rate is used to separate both drugs and UV detection at 245 nm. Good linearities are obtained in concentration range of 0.1-15 μg/ml for simvastatin and 0.6-90 μg/ml for gefitinib. All the proposed methods are extensively validated. They have the advantage of being economic and time saving. The results obtained by adopting the proposed methods are statistically analyzed and compared with those obtained by reported methods.

Keywords: Simvastatin; Gefitinib; First derivative Spectrophotometry; Ratio derivative Spectrophotometry; Multivariate; HPLC.