Novel Kinetic Spectrophotometric Method Using Sodium 1,2-Naphthoquinone-4-Sulphonate for Determination of Desloratadine in Pharmaceutical Formulations
New, sensitive, accurate and inexpensive kinetic spectrophotometric method was developed and validated for the determination of desloratadine (DES) in pure form and pharmaceutical preparations. The method is based on the formation of colored product between DES and sodium 1,2-naphthoquinone-4-sulphonate (NQS). The method involves the reaction of DES with NQS in presence of borax of pH 9 to form colored product with λmax at 485 nm. The fixed time method (15 min) was adopted for constructing the calibration curve. The linearity range was found to be 2.50-37.50 μg/mL. The limit of detection was 0.039 μg/mL. Molar absorptivity for the method was found to be 0.59 × 104 L/mol cm. The determination of DES by the fixed concentration and rate constant methods is feasible with the calibration equations obtained, but the fixed time method proves to be more applicable. Statistical treatment of the experimental results indicates that the method is precise and accurate. The developed method was found to be selective, accurate and precise. The method was successfully applied for the routine quality control analysis of DES in raw material and commercial available dosage forms.
Safwan Ashour, Mohammed Khateeb