New spectrophotometric methods for the simultaneous determination of amlodipine and ramipril

Institute of Pharmacy, Pt. Ravishankar Shukla University, Raipur-492 010, Chhattisgarh, India E-mail : swarnlata_saraf@rediffmail.com Telefax: 91-771-2262832 Manuscript received 28 May 2007, revised 24 April 2008, accepted 26 May 2008 Three new analytical methods were developed based on the simultaneous estimation of drugs in a binary mixture without prior separation of amlodipine and ramipril. Quantitative estimation of these drugs in marketed brands of the tablets was carried out using first order derivative, simultaneous equations and multi wavelength methods. Amlodipine and ramipril have absorbance maxima at 360 nm and 206.5 nm respectively in methanol. Both the drugs obey Beer's law in the concentration range employed for these methods. The results of analysis have been validated statistically and also by recovery studies