An enteric coated oral pharmaceutical formulation comprising as active ingredient a compound selected from the group of omeprazole, an alkaline salt of omeprazole, the (-) enantiomer of omeprazole and an alkaline salt of the (-) enantiomer of omeprazole, wherein the formulation comprises a core material of the active ingredient and optionally an alkaline reacting compound, the active ingredient is core material a separating layer and an enteric coating layer. A hydroxypropyl methylcellulose (HPMC) of low viscosity with a specific cloud point is used in the manufacture of pharmaceutical formulations. Furthermore, the application describes the processes for their preparation and use of the claimed formulations in medicine. 0 S-151 85 Sodertalje, Sweden. ASTRA AKTIEBOLAG 1354/DEL/1998 1354/DEL/1998 INDIA 2009-03-25T18:00:34Z 2005-03-04 1998-05-21 411468 1) MAGNUS ERICKSON 2) LARS JOSEFSSON -2 0 3237 2005-03-04 0 3TqABRVt 2009-04-30T18:54:53Z 127969 1) MAGNUS ERICKSON 2) LARS JOSEFSSON 11814 ASTRA AKTIEBOLAG