Advances in microneedle patches for long-acting contraception

Despite the advances in contraceptives, there is still a high rate of unintended pregnancies worldwide, due in large part to the lack of effective, convenient, and safe birth control methods. Compared with short-acting contraceptives, approaches that offer long-term pregnancy protection have attracted greater interest because of the reduced dosing frequency and improved patient compliance. As a novel transdermal drug delivery system, the microneedle (MN) patch has been widely used for a variety of biomedical applications, including long-acting contraception, due to unique properties, such as painless self-administration and elimination of biohazardous waste. In this review we provide a systemic review of MN patches that have been utilized for long-term contraception, including dissolvable MN patches, polymeric biodegradable MN patches, and silk fibroin-based biodegradable MN patches. The acceptability and biosafety of these contraceptive MN patches are also discussed. Finally, we give our perspectives on the future clinical translation of MN patches for long-acting contraception.