SPL Set ID: 87beaf22-593d-4170-bb58-332c615ef90d

Lamotrigine extended-release tablets, USP 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, USP is a white to pale cream-colored powder and has a pK a of 5.7. Lamotrigine, USP 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 extended-release tablets, USP are supplied for oral administration as 100 mg (gray, round), 200 mg (white to off-white, round), 250 mg (yellow, capsule-shaped), and 300 mg (gray, capsule-shaped) tablets. Each tablet contains the labeled amount of lamotrigine, USP and the following inactive ingredients: hypromellose, lactose monohydrate; magnesium stearate; methacrylic acid copolymer, silicon dioxide, talc, titanium dioxide, and triethyl citrate. In addition, the 100 mg and 300 mg tablets also contain FD&C Blue #2 Aluminum Lake, FD&C Red #40 Aluminum Lake, FD&C Yellow #6 Aluminum Lake (Sunset Yellow Lake) and triacetin. The 200 mg tablets also contain polyethylene glycol 400. The 250 mg tablets also contain black iron oxide, medium chain triglycerides, copovidone, polydextrose, polyethylene glycol 3350, red iron oxide, and yellow iron oxide. Lamotrigine extended-release tablets, USP contain a modified-release formulation as the core. The tablets are coated with an enteric coat, dry coat and color coat, to enable a controlled release of drug in the acidic environment of the stomach. The combination of this and the modified-release core are designed to control the dissolution rate of lamotrigine over a period of time. Meets USP Dissolution Test 7. 1