Journal of the Chilean Chemical Society
versión On-line ISSN 0717-9707
ALIZADEH, NINA y REZAKHANI, ZAHRA. EXTRACTIVE SPECTROPHOTOMETRIC DETERMINATION OF KETOCONAZOLE, CLOTRIMAZOLE AND FLUCONAZOLE BY ION-PAIR COMPLEX FORMATION WITH BROMOTHYMOL BLUE AND PICRIC ACID. J. Chil. Chem. Soc. [online]. 2012, vol.57, n.2, pp.1104-1108. ISSN 0717-9707. http://dx.doi.org/10.4067/S0717-97072012000200010.
The reactions of picric acid and bromothymol blue with three important antifungal drugs containing an imidazole ring ketoconazole (KC) and clotrimazole (CT) and fluconazole (FC) have been studied for the development of simple, rapid, sensitive an extractive-spectrophotometric method for determining the concentration of these drugs. This method is based on the formation of yellow ion-pair complexes between the basic nitrogen of the drug and sulphonphthalein acid dyes, namely; bromothymol blue (BTB) in phosphate buffer of pH =3 and picric acid (PA) in citrate buffer of pH=2.5. The formed complexes were extracted with chloroform and measured at 410 and 415nm for KC, at 410 and 413nm for CT and at 373 and 415nm for FC using PA and BTB, respectively. The analytical parameters and their effects on the reported systems are investigated. Beer's law was obeyed in the range 1-60 , 1-58 and 3-60 ìg/ mL with PA and 3-55, 2-50 and 5-55 ìg/ mL with BTB for CT, KC and FC, respectively. The composition of the ion pairs was found 1:1 by mole ratio and job0 s method in all cases. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations.The results are in good agreement with those obtained by official methods.
Palabras clave : Ketoconazole; Clotrimazole; Fluconazole; Bromothymol blue; Picric acid; Spectrophotometry.