The present invention provides a preparation that is minimally colored through irradiation with light by coating a preparation containing a compound represented by formula (I) or a pharmaceutically acceptable salt thereof, or a crystal thereof with a light stabilizing substance and a polymer, particularly with one or more of titanium oxide and talc used as the light stabilizing substance and hypromellose used as the polymer.本發明係提供一種製劑，係於含有式(I)表示之化合物、其鹽或此等之結晶之製劑中以光安定化物質及高分子做被覆，尤其是以氧化鈦、滑石中之1種以上作為光安定化物質，以羥丙基甲基纖維素作為高分子做被覆，藉此即使經光照射也幾乎不著色。
