Spectrophotometric and spectrofluorimetric determination of some selective serotonin reuptake inhibitors [SSRIs] through ternary complex formation with eosin and copper [II] in pharmaceuticals

ABSTRACT

Two simple, and sensitive, spectrophotometric and spectrofluorimetric procedures have been developed and validated for analysis of selective serotonin reuptake inhibitors [SSRIs] namely, fluoxetine hydrochloride [FX], fluvoxamine maleate [FV] and sertraline hydrochloride [SE]. Both methods were based on the formation of ternary complex between the cited drugs, eosin and copper sulphate, Spectrophotometrically, the complex was estimated by two procedures, the first procedure depends on the extraction of the ternary complex with chloroform. The second spectrophotometric one depends on the direct measurement of the complex after addition of sodium lauryl sulphat. The ternary complexes showed an absorption maximum at 530 nm for the three cited drugs. Different variables and parameters affecting the reactions were studied and optimized. The formed complexes obey Beer's law in concentration range 1-18, 1-16, 0.25-10 micro gml[-1] using the extractive method and 0.4-12, 0.5-14, 0.1-8 micro gml-1 using surfactant with good correlation coefficients. A fluorescence quenching method for the determination of the [SSRIs] through the formed ternary complexes was also investigated to enhance the sensitivity of the analysis. The formed fluorophores were measured at lambda E[x] 310 nm and lambda E[m]510nm for the three drugs. Regression analysis showed good correlation coefficients [0.9996-0.9999] over the concentration ranges 0.1-25, 0.1-15 and 0.1-12 micro gml-1 for FX, FV and SE, respectively. The proposed methods were validated and successfully applied to the analysis of the three drugs in drug substances and drug products with good accuracy. No interference was observed from common pharmaceutical excipients. The results were favorably in good agreement with those obtained by official methods: