SPL Set ID: e55a986a-217f-678e-e053-2a95a90aa779

Lamotrigine, an AED of the phenyltriazine class, is chemically unrelated to existing AEDs. Lamotrigine's chemical name is 3,5-diamino-6-(2,3-dichlorophenyl)- as -triazine, its molecular formula is C 9 H 7 N 5 Cl 2 , and its molecular weight is 256.09. Lamotrigine is a white to pale cream-colored powder and has a pK a of 5.7. Lamotrigine is very slightly soluble in water (0.17 mg/mL at 25°C) and slightly soluble in 0.1 M HCl (4.1 mg/mL at 25°C). The structural formula is: Lamotrigine Tablets USP are supplied for oral administration as 25 mg (white), 100 mg (light peach), 150 mg (cream), and 200 mg (light blue) tablets. Each tablet contains the labeled amount of lamotrigine and the following inactive ingredients: croscarmellose sodium, crospovidone, FD&C Blue #2 Aluminum Lake (200 mg strength only), FD&C Yellow No. 6 Lake (100 mg strength only), lactose monohydrate, magnesium stearate, microcrystalline cellulose, povidone, and yellow iron oxide (150 mg strength only). Meets USP Dissolution Test 3. Chemical Structure