Bioequivalence study of an oral contraceptive containing ethinylestradiol/drospirenone/levomefolate calcium relative to ethinylestradiol/drospirenone and to levomefolate calcium alone

Background: A new tablet formulation containing 0.02 mg ethinylestradiol/3 mg drospirenone/0.451 mg levomefolate calcium (calcium salt containing 0.416 mg L-5-methyltetrahydrofolate) was assessed for bioequivalence compared to the approved oral contraceptive (OC) tablet containing identical amounts of ethinylestradiol and drospirenone and to a tablet containing 0.451 mg levomefolate calcium.

Study design: Forty-four subjects received in an intraindividual crossover design single doses of the new tablet formulation or the established ethinylestradiol/drospirenone tablet or the levomefolate calcium tablet.

Results: Bioequivalence was demonstrated for ethinylestradiol, drospirenone and L-5-methyltetrahydrofolate (active moiety of levomefolate calcium) between the investigated tablet formulations. The geometric mean ratios of the AUC((0-tlast)) and C(max) values for all three compounds and their 90% confidence intervals were well within the 80%-125% range generally accepted to demonstrate bioequivalence.

Conclusion: The rate and extent of absorption of ethinylestradiol and drospirenone were not affected by the concomitant administration of levomefolate calcium and vice versa.