Two different spectrophotometric methods for simultaneous determination of binary mixture of atenolol and amlodipine in commercial formulation

For the simultaneous determination of a binary mixture of amlodipine (AM) and atenolol (AT) in tablets, two approaches were accessible. The first method is the second derivative of the ratio spectra (2DD) that obtained via dividing the absorption spectra of binary mixtures by a standard spectrum of one of the components and then the second derivative of the ratio spectra were calculated. The extended ratio subtraction method (EXRSM) is the second approach, which launches with the ratio subtraction method coupled with 4th derivative spectrophotometry. The calibration curve is linear over the concentration range (2-45) μg/mL and (5-60) μg/mL for amlodipine and atenolol successively. The presented methods have been successfully applied to estimate binary mixtures of amlodipine and atenolol tablets simultaneously and also was satisfactory compared with standard method (HPLC). References ALI, N., ABDELWAHAB, N., EL-FATATRY, H. & OSMAN, W. 2013. Spectrophotometric methods for simultaneous determination of two hypouricemic drugs in their combined dosage form. Pharm Anal Acta, 4, 2-8. ALIZADEH, N. & HEMATI, F. 2014. Spectrophotometric method for the determination of amlodipine besylate in pure and dosage forms using 7, 7, 8, 8-tetracyanoquinodimethane and tetracyanoethylene. Bulletin of Faculty of Pharmacy, Cairo University, 52, 109-114. BLANCO, M., GENÉ, J., ITURRIAGA, H. & MASPOCH, S. 1987. Application of a photodiode array detector to multi-component determination by flow injection analysis. Analyst, 112, 619-622. ÇELEBIER, M., KAYNAK, M. S., ALTıNÖZ, S. & SAHIN, S. 2010. HPLC method development for the simultaneous analysis of amlodipine and valsartan in combined dosage forms and in vitro dissolution studies. Brazilian Journal of Pharmaceutical Sciences, 46, 761-768. COMMISSION, B. P. 2008. British pharmacopoeia 2009, Stationery Office (UK). DARWISH, H., METWALLY, F. H. & EL BAYOUMI, A. 2015. Novel ratio subtraction and isoabsorptive point methods for determination of ambroxol hydrochloride and doxycycline in their combined dosage form: Development and validation. Tropical journal of pharmaceutical research, 14, 133-140. DARWISH, H. W., HASSAN, S. A., SALEM, M. Y. & EL-ZEANY, B. A. 2013. Sequential spectrophotometric method for the simultaneous determination of amlodipine, valsartan, and hydrochlorothiazide in coformulated tablets. International journal of spectroscopy, 2013. DARWISH, H. W., HASSAN, S. A., SALEM, M. Y. & EL-ZEINY, B. A. 2011. Three d