The subject invention provides a pharmaceutical tablet formulation comprising per unit dosage form e.g. per tablet the following ingredients: (a) a compound as an active ingredient, wherein the compound has a formula: wherein R is substituted adamantyl and n is an integer from 0 to 3 or a pharmaceutically acceptable salt thereof； (b) a hydroxypropyl methylcellulose with an apparent viscosity of 80,000 cP to 120,000 cP (nominal value 100,000 cP) when present in a 1% solution； (c) a microcrystalline cellulose； and (d) a magnesium stearate
