Pharmacokinetics and relative bioavailability of digoxin solutionin healthy volunteers

Objective To study the pharmacokinetics and relative bioavailability of digoxin solution and tablet in 20 healthy male volunteers.Methods A single oral dose of 0.75 mg digoxin solution(15 mL) or tablet were given to each volunteer according to an open randomized crossover design. The concentration of digoxin in serum was determined by fluorescent polarization immunoassay. The pharmacokinetic parameters were calculated and the bioequivalence were compared.Results The main pharmacokinetic parameters of digoxin solution and tablet were as follows: AUC_ 0→∞ were (65.19±12.09) and (67.59±9.77) μg·h·L -1 ; AUC_ 0→72 were (42.04±6.25) and (44.91±6.03) μg·h·L -1 ; t_ max were (0.64±0.17) and (1.36±0.79) h; C_ max were (3.99± 1.23 ) and (3.53±1.02) μg.·L -1 ; t_ 1/2 were ( 44.66 ±8.12) and ( 44.67 ±5.02)h.The relative bioavailability of the drug was (94.8± 16.4 )%.Conclusion The two digoxin formulations are bioequivalent.