Single dose bioavailability of two different digoxin tablets.

In a single dose bioequivalence study in 10 healthy young adults the absorption profiles and bioavailability of two digoxin containing tablets (A = digoxin-Pharbita 0.25 mg and reference drug B) were compared and related to the in vitro dissolution rate of both tablets. Two tablets of each product (= 0.50 mg of digoxin) were taken at random on an empty stomach; two weeks elapsed between the two treatments. Frequent blood sampling was performed up to 24 h after intake of the dose. Digoxin plasma concentrations were measured by means of radioimmunoassay. No significant differences (p greater than 0.05) were found in the mean values of the peak plasma concentration (cmax), time to peak (tmax) and area under the plasma concentration versus time curve for the period of 0-10 h after drug intake (AUC0-10), although in most subjects the absorption process after intake of product A was slightly faster, with slightly higher peak. This might be related to a slightly faster release of digoxin from the product A dosage form, as was seen from the dissolution test data. The relative bioavailability of product A as compared to product B, accounted for 97.7 +/- 28.7% (mean +/- S.D.). These results indicate, that both products can be considered as being bioequivalent.