Quantification of terbutaline in pharmaceutical formulation and human serum by adsorptive stripping voltammetry at a glassy carbon electrode

Abstract

The electrochemical oxidative behavior of terbutaline at the glassy carbon electrode was studied in a series of the Britton-Robinson buffer of pH 2-11. Cyclic and square-wave voltammograms of terbutaline at the pH values ≤9 exhibited a single irreversible anodic peak. A fully validated, simple, sensitive and precise square-wave adsorptive anodic stripping voltammetric procedure was described for the determination of terbutaline in bulk form, tablets and human serum. For 5×10-8M bulk terbutaline a mean recovery of 98.78±0.94% (n=5) was achieved following its preconcentration by adsorptive accumulation onto the glassy carbon electrode at a +0.15V (vs. Ag/AgCl/KCls) for 180 s. Limit of detection of 6×10-9M and limit of quantitation of 2×10-8M terbutaline were achieved in the bulk form or its formulations (Bricanyl® tablets). The described square-wave adsorption anodic stripping voltammetric procedure was successfully applied for the determination of terbutaline in human serum following medium exchange. Limit of detection of 1.41×10-8M (3.173 ng ml -1) and limit of quantitation of 4.70×10-8M (10.575 ng ml-1) were achieved in human serum with a mean recovery of 98.11±1.13%. © 2007 Pharmaceutical Society of Japan.