The purpose of this study is to examine the effect of co-administration of AZD6140 and Nordette® on the blood levels of certain female hormones.

Inclusion Criteria:

• Females who are healthy, non-pregnant, not planning pregnancy within the study period, non-breast-feeding, and pre-menopausal
• Either currently taking Nordette® which was well tolerated for at least two months prior to randomisation with no history of break-through bleeding, or, willing to take Nordette for 2 months prior to receiving the study drug
• Females of child-bearing potential must be willing to use at least 1 additional medically approved non-hormonal barrier contraceptive method (for example, condom or diaphragm) that contains spermicide

Exclusion Criteria:

• History of intolerance (e.g. adverse events) to any oral contraceptive or AZD6140
• History of blood vessel or bleeding conditions that would make the volunteer more prone to bleeding
• History or presence of significant medical problems
• Women who are current smokers