Role of Polymers Used in Hormone Delivery of Contraceptive Systems for Prevention of Pregnancy

Pregnancy contraceptive devices such as sub-dermal implants, intrauterine devices (IUD), vaginal tools and transdermal patches recognized as common methods used to long-term protection of pregnancy. Non-biodegradability of subdermal implants and IUDs, also copper burst release in copper based IUD systems and need to surgical help to remove them from patient body and rapid water solubility of microneedles in transdermal patches demonstrated as their main drawback for long-term contraception. In this study polymers properties, especially biodegradable polymers used in contraceptive tools for long-term uses were surveyed. Further of review on the sub-dermal implants, IUDs, vaginal tools including vaginal rings and hydrogel and also trans-dermal patches based microneedles, the role of polymers in structural and performance properties of these systems were investigated. The rates of biodegradability and hormone release are the main factors affected the performance of contraceptive tools. Therefore, applying of biodegradable polymers with natural and biological origins and synthetic polymers such as polylactic-co-glycolic acid (PLGA), due to their biocompatibility, needless to remove from patient body and the controlled release of hormone has attracted the attention of researches. The results showed that the sustained release rate of the hormone was strongly correlated with the structural properties of the polymer.