A composition which comprises substance represented by Formula (I),[Meanings of the symbols that are included in the formula are given in the specification as definitions]a pharmaceutically acceptable carrier, and a dissolution aid.is useful for improving solubility, oral absorbability and/or absorbability in blood of a poorly water-soluble or water insoluble tetracyclic compounds having an ALK inhibitory activity that are useful as a prophylactic and/or therapeutic agent for cancer, depression, and cognitive function disorder.
