Patent ID: 6264970
Filing Date: 2001-07-24
Classification: A61K,C08G

Abstract:
A sustained-release preparation which comprises a bioactive substance having an acidic group and a biodegradable polymer selected from the group consisting of biodegradable polymers (Ia)-(Ig) having the following formulae:POLY-CO--A--X (Ia)wherein, in formula (Ia), POLY represents the principal chain of the biodegradable polymer: A represents O, NH or S: and X represents a hydrocarbon group having 1 to 3 amino groups, ##STR5##wherein, in formula (Ib), POLY represents the principal chain of the biodegradable polymer; X represents a hydrocarbon group having 1 to 3 amino groups; and ring A.sup.1 is a 5- to 7-membered ring, ##STR6##wherein, in formula (Ic), POLY represents the principal chain of the biodegradable polymer: Y represents a hydrocarbon group having 1 to 3 amino groups; and ring A.sup.2 is a 5- to 7-membered ring,X--CO--O-POLY-CO--A--X (Id)wherein, in formula (Id), POLY represents the principal chain of the biodegradable polymer; A represents O, NH or S; and X represents a hydrocarbon group having 1 to 3 amino groups, ##STR7##wherein, in formula (Ie), POLY represents the principal chain of the biodegradable polymer: X represents a hydrocarbon group having 1 to 3 amino groups: and ring A.sup.1 is a 5- to 7-membered ring, ##STR8##wherein, in formula (If), POLY represents the principal chain of the biodegradable polymer; X and Y represent a hydrocarbon group having 1 to 3 amino groups: and ring A.sup.2 is a 5- to 7-membered ring, andX--CO--O-POLY-CO--R.sup.0 (Ig)wherein, in formula (Ig), POLY represents the principal chain of the biodegradable polymer; X represents a hydrocarbon group having 1 to 3 amino groups; and R.sup.0 represents a hydrocarbon group.