An overview of the development of combined oral contraceptives containing estradiol: focus on estradiol valerate/dienogest

摘要

Natural estrogens such as estradiol (E2) or its valerate ester (E2V) offer an alternative to ethinyl estradiol (EE). E2-containing combined oral contraceptives (COCs) have demonstrated sufficient ovulation inhibition and acceptable contraceptive efficacy. However, earlier formulations were generally associated with unacceptable bleeding profiles. Two E2V-containing preparations have been approved to date for contraceptive use: E2V/cypro-terone acetate (CPA) (Femilar®; only approved in Finland and only in women >40 years or women aged 35–40 years in whom a COC containing EE is not appropriate) and E2V/dienogest (DNG; Qlaira®/Natazia®). The objective of the current review is to provide an overview of the development of COCs containing natural estrogen, highlighting past issues and challenges faced by earlier formulations, as well as the current status and future directions. The majority of information to date pertains to the development of E2V/DNG.