ABSTRACT
The reactions of Rose bengal reagent (Rbeng) with three antifungal drugs Fluconazole (FLZ), Voriconazole (VRZ) and Butoconazole nitrate (BTZ) had been studied for the development of simple, rapid, sensitive spectrophotometric methods for micro-determining of these drugs in pure and in their dosage forms. This method is based on the formation of ion-pairs between the drugs and Rbeng reagent. The spectra of the formed ion pairs were measured at pH = 6.5 for FLZ and pH = 6 for VRZ at 575 nm. The spectra of the formed ion pair for BTZ was measured at pH = 4 and 580 nm. All solutions spectra are measured at selected optimum temperature 20-30 oC. Beer's law was valid in the concentration ranges 30.63 – 76.57, 34.93– 97.81 and 14.2 – 45.1 μg ml-1 with recovery of (98.00 - 101.9, 97.92 - 102.2 %, and 98.20 - 101.3 % for FLZ, VRZ and BTZ, respectively. The values SD = 0.1210 – 0.4148, 0.4365– 1.018 and 0.0748 - 0.4362, RSD =0.1790 – 1.152, 0.5248 - 1.648 and 0.3314 - 1.011%, the Sandell sensitivity (S) = 0.063, 0.076, 0.017 μg cm-2, LOQ = 8 , 12.96, 13.27 μg ml-1 and LOD =2.6, 4.4, 4.3 μg ml-1 were calculated for FLZ, VRZ and BTZ, respectively. The results obtained revealed accuracy, precision and sensitivity of the suggested procedures. These methods were applied for analysis of these drugs in their pharmaceutical formulations. The results obtained were found to be in good agreement with those given by official methods, as evaluated by F- and t- tests.