The invention is to provide an oral solid pharmaceutical that is uniform in the content of KRP-197, having bladder-selective anticholinergic activity, being a therapeutic drug for pollakiuria and urinary incontinence, and being active with a very low dosage, that can be taken quantitatively, and that is easy in the handling. Since KRP-197 becomes unstable to light under the influence of additives, the invention is to select the additives to be used and to obtain a pharmaceutical with high stability.By formulating KRP-197 with drug-making carriers, a pharmaceutical that is uniform in the content, capable of taking quantitatively and easy in the handling has been provided. Furthermore, by using polyvinyl pyrrolidone for binder and by making into tablet coated with a coating base containing titanium dioxide and ferric oxide, a pharmaceutical capable of taking quantitatively and excellent in the light stability has been provided.