SPL Set ID: bcaf8db0-1750-425d-b008-255b5e7a9cc6

TWIRLA (levonorgestrel and ethinyl estradiol) transdermal system (TDS) contains 2.60 mg levonorgestrel (LNG) (17α)-(–) [13-ethyl-17¬hydroxy-18, 19-dinorpregn-4-en-20-yn-3-one], a progestin, and 2.30 mg ethinyl estradiol (EE), [(17α)-19-norpregna-1, 3, 5(10)-trien-20-yne-3, 17-diol] an estrogen (Figure 3). Figure 3. Structural Formulas TWIRLA is designed to provide daily exposure of 120 mcg LNG and 30 mcg EE. TWIRLA is a matrix type TDS consisting of a 15 cm 2 active adhesive laminate center, surrounded by a peripheral inactive adhesive laminate. The entire area of TWIRLA is 28 cm 2 . TWIRLA consists of 5 layers and a release liner which is removed and discarded prior to application. The two innermost layers contain the active ingredients (LNG and EE), as well as inactive components. Proceeding from the outer surface toward the surface adhering to the skin, the layers are (1) a woven peripheral backing layer, which is etched with “TWIRLA Levonorgestrel 120 mcg/day Ethinyl Estradiol 30 mcg/day”; (2) an inactive peripheral acrylic adhesive layer; (3) an inactive peripheral polyisobutylene adhesive layer; (4) an internal membrane to separate the active adhesive matrix from the inactive adhesive laminate; (5) the active adhesive matrix (Figure 4). Figure 4. Schematic Depiction of the TWIRLA TDS The inactive components are acrylic adhesives, capric acid, copovidone, crospovidone, dimethyl sulfoxide, ethyl lactate, lauryl lactate, polybutene, polyester internal membrane, polyester release liner, polyisobutylene adhesives, and woven polyester backing membrane. TWIRLA is not made with latex. figure-2 figure-3