14. Female Subjects of child bearing potential unwilling to use effective contraception from the signing of the consent form until completion of two periods after the last dose. An effective method of birth control is defined as one which results in a low failure rate (i.e. less than 1% per year) when used consistently and correctly such as sterilisation, implants, injectables, combined oral contraceptives, Intrauterine Device (IUD), condoms, occlusive caps (cervical/vault caps) with spermicidal foam/gel/film/cream/pessary. True sexual abstinence is acceptable when this is in line with the preferred and usual lifestyle of the subject.