Background & Aims: Losartan is a non-peptide potent antihypertensive agent that acts through blocking angiotensin II receptors. Hyzaar® is a combination product that contains two drugs, losartan and hydrochlorothiazide, used to lower high blood pressure. There are some reports regarding simultaneous measurement of the drugs in pharmaceutical and biological samples which includes HPLC, CE, CEC, ...

Two methods, spectrophotometric and chromatographic-densitometric ones, were developed for determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations. Spectrophotometric method involved derivative spectrophotometry and zero order spectrophotometry. The measurements were carried out at lambda = 224.0 nm for quinapril, lambda = 261.0 nm for...

Rapid, precise, accurate, and specific ratiospectra derivative spectrophotometry and a simple UV spectrophotometry using simultaneous equation methods are developed for the simultaneous determination of bisoprolol fumarate and hydrochlorothiazide from combined pharmaceutical dosage forms. For ratiospectra derivative spectrophotometry, the amplitudes were measured at 202.6 nm for bisoprolol fuma...

Three new spectrophotometric procedures for the simultaneous determination of fosinopril and hydrochlorothiazide are described. The first method, derivative-differential spectrophotometry, comprised of measurement of the difference absorptivities derivatized in the first-order (DeltaD(1)) of a tablet extract in 0.1 N NaOH relative to that of an equimolar solution in methanol at wavelengths of 2...

Theoretical aspects, instrumental devices and analytical applications of derivative ultraviolet-visible region absorption spectrophotometry are reviewed.

A derivative spectrophotometry method was developed to determine enalapril, hydrochlorothiazide, candesartan and walsartan in complex antihypertensive drugs. The pharmaceutical preparations containing hydrochlorothiazide and one of the angiotensin convertase inhibitors were investigated. It was found that the developed method enables the constituents of the investigated drugs to be determined d...

A procedure for simultaneous determination of metoprolol and hydrochlorothiazide in tablets by employing derivative spectrophotometry, "zero-crossing" method was developed. The third order derivative absorption spectra at lambda approximately 281 nm were used for metoprolol and the first order derivative spectra at lambda approximately 282 nm were used for hydrochlorothiazide. No interferences ...

Accurate, precise and selective spectrophotometric and spectrofluorimetric methods were developed and subsequently validated for determination of Torasemide (I), Irbesartan (II) and Olmesartan medoxomil (III), where (I) could be determined in presence of its acidic-degradate as stability indicating method, utilizing derivative ratio spectrophotometry, also in human plasma it could be determined...

Losartan, a highly effective blood pressure lowering agent, has been widely used for the treatment of hypertension. A fast and reliable method for the determination of losartan was highly desirable to support formulation screening and quality control. A first derivative UV spectroscopic method was developed for determination of losartan in the tablet dosage form. The first derivative spectrum r...