SPL Set ID: fb59c76a-9b6f-40ea-ac3a-58c3195c4377

Lamotrigine Extended-Release, 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 Extended-Release Tablets are supplied for oral administration as 25 mg (round beige biconvex film-coated), 50 mg (round white biconvex film-coated), 100 mg (round brown biconvex film-coated), 200 mg (round yellow biconvex film-coated), 250 mg (round white biconvex film coated) and 300 mg (round grey biconvex film-coated) tablets. Each tablet contains the labeled amount of lamotrigine and the following inactive ingredients: hypromellose, lactose monohydrate, magnesium stearate, colloidal anhydrous silica (25 mg, 50 mg, 200 mg, 250 mg and 300 mg tablets only), methacrylic acid copolymer, talc, titanium dioxide, triethyl citrate, sodium bicarbonate, sodium laurel sulfate, iron oxide yellow (25 mg and 100 mg tablets only), iron oxide red (25 mg and 100 mg tablets only), D&C Yellow # 10 (200 mg tablet only), FD&C Yellow # 6 (200 mg tablet only) and black iron oxide (300 mg tablet only). Lamotrigine extended-release tablets contains a modified-release eroding formulation as the core. The tablets are coated with an enteric coat and have pore forming ingredient in the coat to enable a controlled release of the drug in the acidic environment of the stomach. The combinations of the modified-release core and the enteric coat are designed to control the dissolution rate of lamotrigine over a period of approximately 12 to 15 hours, leading to a gradual increase in serum lamotrigine levels. Chemical structure