The invention relates to a stable medicament for oral administration which comprises (a) a core which contains an active ingredient selected from Omeprazole, Lansoprazole and Pantoprazole, together with customary pharmaceutical adjuvants, (b) an intermediate layer applied onto the core, and (c) a gastric juice-resistant outer layer. The intermediate layer in (b) is formed as a reactive layer in which a gastric juice-resistant polymer layer material partially neutralized with alkali with cation exchange capacity is present.Further, a method for the production of the stable medicament is disclosed.