Spectrophotometric Determination of Terbutaline Sulphate and Tetracycline Hydrochloride via ion pair Complex Formation Using Eosin Y

Abstract

A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of terbutaline sulphate and tetracycline hydrochloride drugs in pure form and pharmaceutical formulations. The proposed method is based on the formation of binary complexes between these drugs and eosin Y in aqueous acetate buffered medium. Under the optimum conditions, the binary complexes showed absorption maxima at 545 nm. Beer's law was rectilinear over concentration range of 0.5-10 and 5-45 μg/mL, R2 were 0.9984 and 0.9988, RSD were ≤ 0.72 and ≤ 0.19 (n=5) with average recovery % 101.42 % and 100.08 % and the average recovery values of pharmaceutical formulations 101.48 and 98.01 for above drugs respectively. The limit of detection (LOD) were 0.030 and 0.613 μg/mL and limit of quantitation (LOQ) were 0.103 and 2.00 μg/mL with molar absorptivity values 3.169  103 and 6.347  103 l. mol-1. cm-1 and the relative standard deviation values ≤0.720 and ≤ 0.19 for both drugs respectively. No interference was observed from the excipients that are commonly present in pharmaceutical formulations. The proposed method was successfully applied to the analysis of terbutaline sulphate tablet and tetracycline hydrochloride capsule in their dosage forms.