Drug Information for ISONIAZID TABLETS, USP (Sandoz Inc.): DESCRIPTION

Isoniazid is an antibacterial available as 100 mg and 300 mg tablets for oral administration. Each tablet also contains as inactive ingredients: colloidal silicon dioxide, lactose monohydrate, pregelatinized starch, povidone, and stearic acid.

Isoniazid is chemically known as isonicotinyl hydrazine or isonicotinic acid hydrazide. It has an empirical formula of C₆H₇N₃O and a molecular weight of 137.14. It has the following structure:

Isoniazid is odorless, and occurs as a colorless or white crystalline powder or as white crystals. It is freely soluble in water, sparingly soluble in alcohol, and slightly soluble in chloroform and in ether. Isoniazid is slowly affected by exposure to air and light.