Long-acting methods for fertility regulation

The development of sophisticated technology for the zero-order delivery of contraceptive steroids has been the goal of several public-sector organizations and some pharmaceutical companies for nearly a generation. In fact, a nondegradable implant which delivers the progestogen, levonorgestrel, from silicone rubber (NORPLANT®) has already been approved in six countries and will be submitted for approval by the FDA shortly. Several approaches to biodegradable implants have been attempted with more or less success.