The present invention provides a pharmaceutical formulation comprising clomipramine or its pharmaceutically acceptable salt (preferably, clomipramine hydrochloride) as the first active ingredient, and sildenafil or its pharmaceutically acceptable salt (preferably, sildenafil citrate) as the second active ingredient, wherein stability of clomipramine is improved, and a method for manufacturing this pharmaceutical formulation. In particular, the present invention provides a pharmaceutical formulation comprising the above two active ingredients and manufactured by using a wet granulation method, wherein stability of clomipramine is improved, and a method for manufacturing this pharmaceutical formulation.
