Development of UV Spectrophotometric Procedures for Determination of Amlodipine and Celecoxib in Formulation: Use of Scaling Factor to Improve the Sensitivity

Figure 5

The first-order derivative spectra of AMD (brown), COX (blue), and a mixture of AMD and COX (red). (a) AMD (4 μg/ml) showing the same absorbance in pure and mixture at zero crossings for COX. (b) COX (20 μg/ml) showing the same absorbance in pure and mixture at zero crossings of AMD.