spectorphotometric methods for determination of terbutaline sulphate in pure and pharamaceutical formulation

Two simple, sensitive, and accurate spectrophotometric methods are described to determine terbutaline sulfate in pure and pharmaceutical formulations. they are primarily based totally on the oxidation of terbutaline sulfate with fe(iii) in the medium of nitric acid and the resulting fe(ii) subsequent chelation with 1,10-phenanthroline (1,10-phen) in method a and with 2,2´-bipyridyl (2,2’-bipy) in method b. the resulting color chromogens were measured at 510 and 522 nm in the above methods, respectively. the two methods a and b were obeyed beer's law in the ranges of 0.1 - 2.0 and 0.1 - 1.2 μg ml-1 with molar absorptivity values of 2.44 × 10^5 and 3.27 × 10^5 l mol-1. cm-1, respectively. the relative standard deviation (rsd) values were found ≤5.53% and ≤ 3.15%, respectively. the reaction mechanisms have been established. the suggested methods were applied successfully for the assay of terbutaline sulfate in its commercial formulations as syrup and tablet and the obtained results were compared statistically with the official method.