To obtain the subject liquid which is excellent in the penetration of a glucocorticoid to nails and the effective rate in vivo, contains no additional solvent or substance promoting diffusion or penetration and is useful as a medicine for nail psoriasis by formulating the glucocorticoid, a solvent and a water- insoluble film forming agent.

This liquid includes (A) at least one kind of glucocorticoid (suitably alclometasone dipropionate and the like), (B) at least one kind of physiologically permissible solvent and (C) at least one kind of water-insoluble film forming agent (suitably a copolymer between methyl vinyl ether and monobutyl maleate and the like). Further, it is preferable that clobetasol propionate and the like are included as active compounds and at least one kind of the active compound is contained in the whole concentration of 0.5-20 wt.% based on the whole weight of the preparation.