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

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

Fluorescence spectral behaviour of amlodipine besylate and dobutamine hydrochloride and their determination in dosage forms and spiked plasma

The present work describes sensitive, simple and validated fluorimetric methods for the determination of Amlodipine besylate [AM] and Dobutamine Hydrochloride [DO]. The methods depend on measurement of native fluorescence intensity of both drugs at lombda emission 450nm, and 310nm using lombda excitation 360nm and 272nm for both drugs. The fluorescence spectral properties of AM and DO was also achieved in presence of different surfactants, beta-cyclodextrin and some metal ions. Quantum yield, formation constant [K] and free energy changes [delta G] values were calculated, for all the suggested methods under the optimum condition and experimental parameters. Linear relationships and good correlation coefficients [0.9995-0.9999] were found between fluorescence intensity, and the concentration ranges of the investigated drugs. No interference was observed when the methods were applied in the presence of co- administrated and common drugs. Moreover the methods can be used as stability indicating methods for AM. The results obtained were statistically comparable with those obtained by official methods. The proposed methods were successfully applied to the determination of AM and DO in bulk powder, dosage forms, and spiked human plasma. The validity of the methods was assessed according to USP guidelines and also by applying the standard addition technique