SPL Set ID: eb436371-d188-4803-a864-07b90c357e57

Lamotrigine, 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 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, USP are supplied for oral administration as 25 mg, 50 mg, 100 mg, 200 mg, 250 mg, and 300 mg tablets. Each tablet contains the labeled amount of lamotrigine and the following inactive ingredients: glyceryl monostearate, hypromellose, lactose monohydrate, magnesium stearate, methacrylic acid copolymer dispersion, polyethylene glycol, polysorbate 80, triethyl citrate, titanium dioxide and water. Apart from this: 25 mg tablet contains D&C yellow #10 aluminum lake, iron oxide red and iron oxide yellow. 50 mg tablet contains D&C yellow # 10 aluminum lake, FD&C blue # 2, ferric oxide yellow. 100 mg tablet contains D&C yellow # 10 aluminum lake, D&C red # 27, ferric oxide yellow. 200 mg tablet contains FD&C blue # 2 aluminum lake, ferrososferric oxide. 250 mg tablet contains carmine, FD&C blue # 2 aluminum lake, ferrososferric oxide. 300 mg tablet contains FD&C blue # 2 aluminum lake, ferric oxide yellow, ferrosoferric oxide. Lamotrigine extended-release tablets, USP contain a modified-release eroding formulation as the core. The tablets are coated with a modified enteric coating to enable a controlled release of drug in the acidic environment of the stomach. The combination of modified-release core and the modified enteric coating 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. Product meets USP dissolution test# 9. Lamotrigine extended-release tablets