Soft-gelatin capsule formulation

A soft gelatin capsule formulation of a 15-keto-prostaglandin compound, which comprises:

• a soft gelatin capsule shell comprising gelatin and a sugar alcohol as a plasticizer, and
• a mixture comprising a 15-keto-prostaglandin compound and a pharmaceutically acceptable vehicle, which is filled in the shell,
• wherein the pharmaceutically acceptable vehicle is a fatty acid ester or a polyol,
• wherein the 15-keto-prostaglandin compound is a compound of the formula (I):
• wherein L, M and N are hydrogen, hydroxy, halogen, lower alkyl, hydroxy(lower)alkyl, lower alkanoyloxy or oxo, wherein at least one of L and M is a group other than hydrogen, and the five-membered ring may have at least one double bond;
• A is —CH3, or —CH2OH, —COCH2OH, —COOH or a functional derivative thereof;
• B is —CH2—CH2—, —CH═CH— or —C═C—;
• R1 is a saturated or unsaturated bivalent lower or medium aliphatic hydrocarbon residue, which is unsubstituted or substituted with halogen, lower alkyl, hydroxy, oxo, aryl or heterocyclic group, and at least one of carbon atom in the aliphatic hydrocarbon is optionally substituted by oxygen, nitrogen or sulfur;
• and
• Ra is a saturated or unsaturated lower or medium aliphatic hydrocarbon residue, which is unsubstituted or substituted with halogen, oxo, hydroxy, lower alkyl, lower alkoxy, lower alkanoyloxy, cyclo(lower)alkyl, cyclo(lower)alkyloxy, aryl, aryloxy, heterocyclic group or heterocyclicoxy group;
• lower alkoxy;
• lower alkanoyloxy;
• cyclo(lower)alkyl;
• cyclo(lower)alkyloxy;
• aryl;
• aryloxy;
• heterocyclic group;
• heterocyclicoxy group.