A new sensitive, simple, rapid, accurate and precise method for simultaneous quantification of nebivolol HCl (NEB) and hydrochlorothiazide (HCT) in combined tablet dosage form has been developed. The method is based on the derivative spectrophotometric method at zero-crossing wavelengths. Two wavelengths 280nm (zero crossing point for NEB) and 272.2nm (zero crossing point for HCT) were selected for the quantification of hydrochlorothiazide and nebivolol HCl respectively, using phosphate buffer pH 3.6 as solvent. The first derivative amplitudeconcentration plots were rectilinear over the range of 4-24 μg mL-1 and 2-32 μg mL-1 with detection limits of 0.127 and 0.230 μg mL-1 and quantification limits of 0.425 and 0.769 μg mL-1for hydrochlorothiazide and nebivolol HCl respectively. The proposed method was statistically validated as per ICH guidelines. The percentage recovery was within the range between 97-101 and % relative standard deviation for precision and accuracy of the method was found to be less than 2%. The proposed method was effectively applied to routine quality control analysis of studied drugs in their tablet formulations.
