Provided are a method for producing a solid pharmaceutical preparation substrate and a solid pharmaceutical preparation substrate formed by said method which can easily improve durability of a printed image formed by an ink jet method on a surface of a solid pharmaceutical preparation even when a dye pigment is used as a color material of a water soluble ink for ink jet printing. The method for producing a solid pharmaceutical preparation substrate according to the present invention uses a water soluble ink that includes a water soluble solvent with a high boiling point to print an image by an ink jet printing method on a surface of a solid pharmaceutical preparation base material (1) and carries out a thermal preservation process after the printing. According to the method, the thermal preservation process is carried out immediately after printing while a printed image (9) is not completely dry and ink fluidity is improved, and thus the ink attached to the surface of the solid pharmaceutical preparation base material (1) penetrates inside the solid pharmaceutical preparation base material (1) during the thermal preservation process and does not tend to be directly affected by light or humidity from outside. Therefore, durability of the printed image (9) can be improved.Linvention concerne un procédé de production dun substrat de préparation pharmaceutique solide et un substrat de préparation pharmaceutique solide formé par ledit procédé qui peut facilement améliorer la durabilité dune image imprimée formée par un procédé de jet dencre sur une surface dune préparation pharmaceutique solide même lorsquun pigment coloré est utilisé comme matériau coloré dune encre soluble dans leau pour limpression par jet dencre. Le procédé de production dun substrat de préparation pharmaceutique solide selon la présente invention utilise une encre soluble dans leau qui comprend un solvant soluble dans leau ayant un point débullition élevé pour imprimer une image grâce à un procédé d
