Abstract

A spectrofluorimetric method has been developed for the determination of tetracycline hydrochloride and terbutaline sulphate in different dosage forms. The method is based on the quantitative quenching effect of tetracycline hydrochloride and terbutaline sulphate on the native fluorescence of Eosin Y at the pH 6.4 and 3.5 respectively. The quenching of the fluorescence of Eosin Y was measured at 545 nm after excitation at 350 nm. The fluorescence-concentration plots are rectilinear over the range 0.5–18 and 0.05-5.0 μg mL-1 with LOD of 0.531and 0.241 μg mL-1 and LOQ of 1.77 and 0.806 μg mL-1
for above drugs respectively. The proposed method has been successfully applied to the analysis of commercial tablets and capsules containing the drug. Statistical comparison of the results with those of the reference method revealed good agreement and proved that there were no significant differences in the accuracy and precision between the two methods.

Key words: Tetracycline; terbutaline sulphate; Eosin Y; fluorimetry.