Suppository preparation having excellent absorption property

A suppository having excellent absorption property, comprising (1) a water-soluble medicine, (2) a water-soluble substance selected from the group consisting of water-soluble salts and water-soluble saccharides at a concentration exhibiting 1.5-6.0 fold of osmotic pressure of isotonic sodium chloride solution, and (3) at least 0.01 W/W % of an absorption promoter which is at least one N-acyl amino acid derivative or N-acyl peptide derivative represented by the formula:

• R--CO--A,
• wherein R is an aliphatic hydrocarbon group, a substituted aliphatic hydrocarbon group, an aromatic hydrocarbon group, a substituted aromatic hydrocarbon group, an aryl-substituted lower hydrocarbon group or a substituted aryl-substituted lower hydrocarbon group;
• wherein said substituted aliphatic hydrocarbon group, said substituted aromatic hydrocarbon group or said substituted aryl-substituted lower hydrocarbon group is substituted with a member selected from the group consisting of a lower alkyl group, a hydroxyI group, a carboxylic acid group, an alkoxy group, a phosphoric acid group, an amino group, an imino group and a halogen;
• and A is an amino acid residue or a peptide residue.