The molecular weight of tramadol hydrochloride is 299.8.Tramadol hydrochloride is a white, bitter, crystalline and odorless powder. It is readily soluble in water and ethanol and has a pKa of 9.41.The n-octanol/water log partition coefficient (logP) is 1.35 at pH 7. ULTRAM tablets contain 50 mg of tramadol hydrochloride and are white in color. Inactive ingredients in the tablet are corn starch, hydroxypropyl methylcellulose, lactose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80,sodium starch glycolate, titanium dioxide and wax. Tramadol is sometimes used to treat pain. Visit WebMD for additional health information!