SENSITIVE DETERMINATION OF DIGOXIN IN TABLETS BY FLOW-INJECTION WITH FLUORESCENCE DETECTION

A sensitive flow injection (FI) fluorimetric procedure is described fo r the determination of digoxin in tablets. The approach is rapid and h as resulted in automatable methods for dissolution testing, uniformity of content and bulk assay of a 0.25 mg tablet formulation. Tablet ext racts are injected into a single flowing stream of alcoholic hydrochlo ric acid containing benzoyl peroxide and ascorbic acid. An on-line hea ting stage facilitates the rapid formation of fluorescent species, whi ch are detected using excitation and emission wavelengths of 364 and 4 88 nm, respectively, The methods have been fully validated and are lin ear down to 0.5 mu g ml(-1), This approach is also applicable to other digoxin formulations.