Current location: JICS Archive > Vol. 3 > No. 3 > Articles : 9
A New Spectrophotometric Method for the Determination of Nadolol
O.A. Adegoke*, O.S. Idowu and A.A. Olaniyi
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
A new spectrophotometric method has been developed for the assay of nadolol in pure form and in tablets. The assay procedure is based on a derivatization methodology employing 4-carboxyl-2,6-dinitrobenzene diazonium ion (CDNBD) as a diazo coupling reagent. The azo dye formed between nadolol and CDNBD absorbed visible light at the wavelength maximum of 416 nm (λmax) demonstrating a bathochromic shift from the absorption maximum of nadolol. Optimization studies established an optimal reaction time of 10 min at 60 °C. The assays were linear over 1.25-10 µg ml-1 of nadolol, and the reaction occurred by a 3:1 reagent/drug stoichiometric ratio. The method is found to be selective and has a lower detection limit of 0.29 µg ml-1. Recovery studies over three days gave mean recovery of 101.4% (RSD 3.0%). This new method has been successfully applied in the determination of nadolol and nadolol/bendroflumethiazide tablets with accuracy and precision similar to the official (USP) HPLC procedure (p > 0.05). The new procedure has the advantages of high sensitivity, lower limit of detection and could find application as an in-process quality control method for nadolol.
Keywords: Nadolol, Diazo coupling, Phenol ether, CDNBD, Spectrophotometry
