Disclosed is a solid pharmaceutical composition comprising (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl 2-ethoxy-1-{ [2'-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]methyl} -1H-benzimidazole-7-carboxylate or a salt thereof, and a pH control agent having pH 2 to 5 and a process of preparation.