To establish a technique for stably formulating an isoquinolin-6-amino derivative as an ophthalmic agent or the like. A pharmaceutical preparation is provided including an aqueous composition containing a compound represented by the following formula (1)(in the formula, R1 and R2 each independently represent a hydrogen atom or a C1-C4 alkyl group,R3 represents a hydrogen atom or a hydroxy group, and "A" represents -CH(R4)- or -CH2-CH(R4)- (wherein R4 represents an optionally substituted C6-C10 aryl group, or an optionally substituted 5 to 10-membered heteroaryl group), andthe formula (1) also includes a tautomer thereof.) or a salt thereof or a solvate thereof, the aqueous composition being housed in a container formed of a polyester resin or a polyolefin resin.
