The present invention pertains to a solid dispersion containing a compound represented by general formula (I) (wherein R1 represents an unsubstituted phenyl group or a phenyl group substituted with a substituent; the substituent represents an alkyl group comprising 1–8 carbon atoms, an alkyl group comprising 1–8 carbon atoms substituted with a halogen atom, an alkoxy group comprising 1–8 carbon atoms, an alkoxy carbonyl group comprising 2–8 carbon atoms, a formyl group, a carboxyl group, a halogen atom, a phenyl group, or a phenoxy group; R2 represents a cyano group or a nitro group; R3 represents a hydroxy group; X represents an oxygen atom or -S(O)n-; n represents an integer in a range of 0–2; and Y represents an oxygen atom or a sulfur atom), or a pharmaceutically acceptable salt thereof, and a hypromellose derivative.