CYCLIC PEPTIDE AS ABSORPTION ACCELERATOR

PURPOSE: To accelerate absorption of a peptide and a protein by using a specific cyclic peptide as an auxiliary in administrating the peptide and the protein to a mucous membrane. CONSTITUTION: This medical composition contains a compound expressed by the formula (B is a basic amino acid; A/B is an acidic or a basic amino acid; X is a neutral and hydrophilic amino acid; L is a lipophilic neutral amino acid; R is H or acyl) as an auxiliary for accelerating absorption of a peptide and a protein in administrating the peptide and the protein to a mucous membrane (e.g. nose, oral cavity or rectum cavity). As the compound of the formula, bacitracins, colistins, circulins, polymyxins, etc., well-known as a peptide antibiotic, are especially suitable. The absorption accelerator does not induce a pain or an ache caused by an inflammation, etc., because of not having an irritation to a mucous membrane.