In an eight-subject two-way crossover study, 0.5-mg oral doses of digoxin were administered as two 0.25-mg tablets made by two different manufacturers. Treatment "B" yielded average peak plasma levels and areas under the curves that were 59% and 55%, respectively, of those attained following treatment "A". Two of the eight subjects also received the same dose in 5% dextrose both orally and by constant rate intravenous infusion during a one-hour period. Average peaks were 4.19, 3.76, 1.46, and 0.70 ng/ml following the intravenous infusion, solution orally, treatment A (tablet) orally, and treatment B (tablet) orally, respectively. Relative areas under the curves were 100%, 80.2%, 56.7%, and 30.7% for the treatments in the same order.
Wagner JG, Christensen M, Sakmar E, Blair D, Yates JD, Willis PW, Sedman AJ, Stoll RG. Equivalence Lack in Digoxin Plasma Levels. JAMA. 1973;224(2):199-204. doi:10.1001/jama.1973.03220150013004