SPL Set ID: 93b4b34c-6dba-4aec-b98e-b2b18feb86a9

Primidone, USP is a white, crystalline, highly stable substance, M.P. 279 to 284° C. It is poorly soluble in water (60 mg per 100 mL at 37°C) and in most organic solvents. It possesses no acidic properties, in contrast to its barbiturate analog. Chemical name: 5-ethyldihydro-5-phenyl-4,6 (1H, 5H)-pyrimidinedione. Structural formula: Primidone tablets USP, 50 mg and 250 mg, contain the following inactive ingredients: corn starch, lactose monohydrate, magnesium stearate, methyl cellulose, microcrystalline cellulose, sodium lauryl sulfate, sodium starch glycolate.