[Problems] The object is to improve the absorbability of a heterocyclic compound including s-triazine and a pyrimidine derivative in vitro. [Means for Solving Problems] Disclosed is, for example, an amorphous body of a heterocyclic compound as represented by the general formula (I) [wherein each of R's and others is as defined in the description] including s-triazine and a pyrimidine derivative, or a hydrate, a solvate or a pharmaceutically acceptable salt of the heterocyclic compound. Also disclosed is a process for producing the amorphous body. Further disclosed are: a solid dispersion comprising the amorphous body; and a medicinal preparation comprising the solid dispersion.