An object of the present invention is to provide a pharmaceutical composition that improves intestinal absorption of a compound having a structure represented by the general formula [1]. The composition containing a compound represented by the general formula [1] or a salt thereof and (b) a lipophilic substance improves intestinal absorption of the compound. In the formula, A represents —(NR4)—, —(CR5R6)— or the like; B represents an alkylene group or an alkenylene group; R1 represents an alkyl group, an alkenyl group or the like; R2 represents an adamantylalkyl group or the like; R3 represents an unsaturated heterocyclic ring; R4, R5 and R6 each represent a hydrogen atom or the like; and X represents an oxygen atom or the like.