A triterpenoid compound, methyl 2-cyano-3,12-dioxoleana-1,9(11)-dien-28-oate (CDDO methyl ester), has a non-crystalline, glassy solid form and a non-hydrous crystalline form that can prepared, for example, from a saturated methanol solution. The glassy form displays an enhanced bioavailability over the non-hydrous crystalline form. Each form of CDDO methyl ester is a superior candidate for use, typically in solid dosage form, for treating a variety of disease states, generally associated with inflammation.