Development of controlled release systems over the past 50years in the area of contraception.

The field of controlled release has contributed significantly to female reproductive health and in particular the prevention of unintended pregnancy. For at least 50years, there have been significant advances in controlled release dosage forms used for contraception. These advances have been driven by the need to provide women a wide array of products that address adherence problems noted with oral contraceptives. The first long-acting injectable product (Depo-Provera®) was approved in the US in 1959. Since then, there has been an emphasis on development of long-acting reversible contraceptives. These products include implants, intrauterine systems, and vaginal rings. A shorter acting contraceptive option is the transdermal patch. Despite these advances there are still a large number of unplanned pregnancies around the world. New controlled release technologies will be needed to continue providing women safe and easy to use contraceptive products.