Simultaneous determination of some anti-hypertensive drugs in their binary mixture by novel spectrophotometric methods

Three simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of Irbesartan (IRB) and Hydrochlorothiazide (HCT) namely; ratio subtraction coupled with constant multiplication (RS-CM), ratio difference (RD) and constant center (CC).