A Drug Interaction Study of Folic Acid and Oral Contraceptive Tablets Containing Norgestimate (NGM) /Ethinyl Estradiol (EE) in Healthy Women.

• Evaluate the pharmacokinetic drug interaction between folic acid and the study drug (250 mcg NGM and 35 mcg EE) as measured by the pharmacokinetics of the active breakdown product of NGM, norelgestromin (NGMN), and EE.
  

• Measure the pharmacokinetics of the active metabolite of NGM, norgestrel (NG). Evaluate the effect of the study drug on the pharmacokinetics of folic acid. Assess the safety.
  

This is a single-center, open-label, pharmacokinetic drug interaction study between folic acid (1 mg) and study drug (250 mcg NGM/35 mcg EE) in 2 groups of at least 20 healthy women each. In Group 1, a single oral dose of 250 mcg NGM/35 mcg EE study drug was administered to the healthy volunteers at the study site on Days 1 and 17 and folic acid 1 mg was administered orally on Days 4 to 18; in Group 2, folic acid 1 mg was administered orally on Days 1 and 17 at the study site and 1 tablet of study drug was administered on Days 2 to 17. Blood samples were collected at specified times for 72 hours postdose on Days 1 and 17 for the healthy volunteers in Group 1 for determination of blood levels of norelgestromin (NGMN), and norgestrel (NG) [the active breakdown product of NGM], and EE. For the healthy volunteers in Group 2, blood samples were collected for 24 hours after the folic acid dose on Days 1 and 17 for determination of plasma levels of total folates. Safety was evaluated based on the following: the incidence, type and severity of adverse events; clinical laboratory tests; vital sign and electrocardiogram (ECGs) measurements; and physical examinations. Oral temperature, pulse, respiratory rate, and sitting blood pressure (BP) were taken before dosing on Days 1 and 17. For Group 1, measurements were taken before and at least 15 minutes after the 24-hour (Days 2 and 18), 48-hour (Days 3 and 19), and 72-hour (Day 4) pharmacokinetic blood draw; and at study completion (Day 20) or early withdrawal. For Group 2, measurements were taken before and at least 15 minutes after the 24-hour pharmacokinetic blood draw on Days 2 and 18; and at study completion (Day 18) or early withdrawal. Physical and gynecologic examinations and 12-lead ECGs were performed at screening and at study completion or early withdrawal. Blood samples for blood chemistry, hematology, and urine samples for urinalysis were collected at the screening visit and at the follow-up visit or early withdrawal.

Oral contraceptives tablet (250 mcg NGM/35 mcg EE); Folic acid tablet (1 mg). In Group 1, a single oral dose of (250 mcg NGM/35 mcg EE) study drug was administered on Days 1 and 17 and folic acid 1 mg was administered orally on Days 4 to 18; in Group 2, folic acid 1 mg was administered orally on Days 1 and 17 and 1 tablet of study drug was administered on Days 2 to 17. Study drugs were taken with 240 mL (8 oz) of water at approximately 8:00 a.m.