It is intended to provide preparations such as capsules containing an acid-unstable medicament (in particular, a benzimidazole compound having an antiulcer effect, etc.) at a high concentration which are prepared by using about 12% by weight or more (based on the total granules) of the acid-unstable chemical and blending a basic inorganic salt therewith to give granules of about 600 mu m or more in the average particle size.