Drug delivery for the treatment of endometriosis and uterine fibroids

Endometriosis and uterine fibroids (also known as uterine leiomyomas) are serious medical conditions affecting large numbers of women worldwide. Many women are asymptomatic but those with symptoms require medical intervention to relieve chronic pain and dysmenorrhea and to address infertility. Drug delivery has played a role in reducing some of the symptoms associated with endometriosis and uterine fibroids. Use of drug delivery systems for both conditions can roughly be divided into two categories: (1) existing systems designed for other indications such as contraception for symptomatic relief and (2) development of novel systems aimed at addressing some of the underlying biochemical changes associated with endometriosis and uterine fibroids such as oxidative stress, angiogenesis, and matrix degradation. The latter drug delivery approaches rely heavily on nanotechnology. Existing systems that deliver estrogens and/or progestins include vaginal rings, transdermal patches, and intrauterine systems. Long-acting implantable contraceptives such as Implanon (R) and injectables such as Depo-Provera (R) have found use in treating endometriosis. Similarly, long-acting GnRH products (e.g., Lupron Depot (R)) are used to treat endometriosis. Other drugs formulated in long-acting formulations include intravaginal rings capable of delivering selective progesterone receptor modulators, androgens such as danazol, and aromatase inhibitors (e.g., anastrozole). Nanoparticles composed of silica, poly(lactic-coglycolic acid), cerium oxide, dendrimers, and chitosan/polyethyleneamine have all been investigated to improve treatment of endometriosis and to a lesser extent, uterine fibroids.