Comparative study of analytical methods by direct and first-derivative UV spectrophotometry for evaluation of losartan potassium in capsules

Abstract

Losartan potassium is an antihypertensive non peptide agent, which exerts its action by specific blockade of angiotensin II receptors. The aim of the present study was the validation and application of analytical methods for the quality control of losartan potassium 50 mg in pharmaceutical capsules, using direct and first derivative UV spectrophotometry. Based on losartan potassium spectrophotometric characteristics, a signal at 205 nm of the zero order spectrum and a signal at 234 nm of the first derivative spectrum, were found adequate for quantification. The results were used to compare these instrumental techniques. The linearity between the signals and concentrations of losartan potassium in the ranges of 3.0 7.0 mg L 1 and 6.0 14.0 mg L 1 for direct and first derivative spectrophotometry in aqueous solutions, respectively, presented a correlation coefficient (r) of 0.9999 in both cases. The methods were applied for losartan potassium in capsule dosage obtained from local pharmacies, and were shown to be efficient, easy to apply and low cost. These methods do not use polluting reagents and require relatively inexpensive equipment.Uniterms: Losartan potassium. Direct UV spectrophotometry. First derivative UV spectrophotometry.O losartano potássico é um agente anti hipertensivo não peptídico, que exerce sua ação por bloqueio específico dos receptores da angiotensina II. Este trabalho propôs a validação e aplicação de métodos analíticos orientados ao controle de qualidade de losartano potássico 50 mg na forma farmacêutica cápsula, utilizando a espectrofotometria direta e derivada de primeira ordem na região do UV. Baseado nas características espectrofotométricas de losartano potássico, um sinal a 205 nm do espectro de ordem zero e um sinal a 234 nm do espectro de primeira derivada foram adequados para a quantificação. Os resultados foram usados para comparar essas duas técnicas instrumentais. O coeficiente de correlação entre as respostas e as concentrações de losartano potássico na faixa de 3,0 7,0 mg L 1 e 6,0 14,0 mg L 1 para espectrofotometria direta e derivada de primeira ordem em solução aquosa, respectivamente, foi de (r) of 0,9999 para ambos os casos. Os métodos foram aplicados para quantificação de losartano potássico em cápsulas obtidas de farmácias de manipulação locais e demonstraram ser eficientes, fáceis de aplicar e de baixo custo. Além disso, não necessitam de reagentes poluentes e requerem equipamentos economicamente viáveis.Unitermos: Losartano potássico. Espectrofotometria direta. Espectrofotometria derivada de primeira ordem. INTRODUCTIONLosartan potassium (Figure 1) is an imidazole derivative, chemically described as 2 butyl 4 chloro 1 [p-(o-1H-tetrazol 5 ylphenyl)benzyl]imidazole 5 methanol monopotassium salt. Losartan was developed by DuPont Merck laboratories as a potent non peptide angiotensin II receptor (type AT 1 ) antagonist for hyper tension treatment (Barreiro, Fraga, 2001;Korolkovas, 2007). Losartan is administered in its active form and R. Bonfilio, L. B. Favoretto, G. R. Perei...

Losartan

“…Bonfilio et al [17] reported a direct and first-derivative UV-spectrophotometric method for determination of losartan in capsules. Based on losartan potassium spectrophotometric characteristics, a signal at 205 nm of the zero-order spectrum and a signal at 234 nm of the firstderivative spectrum were found adequate for quantification.…”

Spectrophotometric methods for the simultaneous estimation of losartan potassium and hydrochlorothiazide in tablet dosage forms

“…It is the prototype of the thiazide group and antihypertensive drug. [2]  156  Rao, et al: Spectrophotometric method for losartan potassium and hydrochlorothiazide Literature survey reveals that LSP was determined by several methods including Spectrophotometric, [3][4][5][6] high performance liquid chromatography (HPLC) [6][7][8][9] and liquid chromatography, capillary electrophoresis and supercritical fluid chromatography. [10] HZ was determined by capillary electrophoresis [11] and electrochemical study [12] and by spectrophotometrically, [13][14][15][16][17] reverse phase-HPLC (RP-HPLC).…”

Application of high-performance thin-layer chromatography for screening and simultaneous determination of some angiotensin II receptor antagonists in dosage forms and plasma

“…Olmesartan medoxomil was kindly supplied by Chemipharm Pharmaceutical Co. (6th of October, Egypt). The purity values of the studied drugs were 98.21 ± 1.22, 98.55 ± 1.54, 98.09 ± 0.89, and 98.66 ± 1.48 for losartan, irbesartan, valsartan, and olmesartan, respectively, and they were periodically checked via ultraviolet (UV)-spectrophotometry [2][3][4][5] and TLC measurements [6,26,[28][29], and no further purification steps were required. Chloroform and glacial acetic acid were of chromatographic grade (El-Nasr Pharmaceutical Chemicals, AboZaabal, Egypt).…”

“…The chemical structures of the studied drugs are shown in Figure 1. Different spectrophotometric [2][3][4][5][6][7] and spectroflourimetric [8][9][10] methods have been used for their quantification. Also, flow injection method was reported for their determination [11].…”