Abstract
The present research study describes the use of response surface methodology by Box-Behnken design in optimization and validation of the new microwell-based UV-Visible spectrophotometric method for determination of CEF in its formulation. The absorbance of the colored-charge transfer (CT) complex was measured at 460 nm by microwell-plate absorbance reader. Under the optimum conditions, linear relationship with good correlation coefficient (0.999) was found between the absorbance and the concentration of CEF in the range of 10-100 mu g/well. The limits of detection and quantitation were 2.06 and 6.85 mu g/well, respectively. The relative standard deviations did not exceed 4.03% for the intra- and inter-assay precisions The assay was successfully applied to the analysis of CEF in its pharmaceutical dosage forms with good accuracy and precision. The assay described herein has great practical value in the routine analysis of CEF in quality control laboratories, as it has high throughput property, consumes minimum volume of organic solvent thus it offers the reduction in the exposures of the analysts to the toxic effects of organic solvents. This multivariate approach enables substantial improvement in the method development using fewer experiments, without wastage of large volumes of organic solvents, which leads to high analysis cost.