US regulators have issued a green light for Warner Chilcott's new oestrogen/progestin-based oral contraceptive, which is yet to be given an official trade name.

The product is a chewable combination of norethindrone acetate and ethinyl estradiol and ferrous fumarate tablets, approved by the US Food and Drug Administration for the prevention of pregnancy.

The oral contraceptive regimen consists of 24 white active chewable tablets that contain the active ingredients, followed by four brown non-hormonal placebo tablets containing ferrous fumarate.

Approval was based on data from a six-month clinical trial involving 743 women aged 18-45 years, which showed the risk of getting pregnant to be about one-four in 100 women during the first year of use.

The pill was also found to be generally well-tolerated, with the most common side effects observed being: headache (6.3%); vaginal candidiasis (6.1%); nausea (4.6%); menstrual cramps (4.4%); breast tenderness (3.4%)' bacterial vaginitis (3.1%); abnormal cervical smear (3.1%); acne (2.7%); mood swings (2.2%); and weight gain (2.0%).

The Dublin, Ireland-based company said it expects to launch the new contraceptive, which is being manufactured by a third party, in August this year.