DDC COMPOUNDS AND METHODS FOR ASSAYING THE SAME

1. A DDS compound which comprises a carboxy(C1-4)alkyldextran polyalcohol modified with a saccharide compound and a residue of drug compound bound to the carboxy(C1-4)alkyldextran polyalcohol. 2. The DDS compound according to claim 1, wherein the carboxy(C1-4)alkyldextran polyalcohol modified with a saccharide compound and the residue of drug compound are bound to each other by means of a spacer. 3. The DDS compound according to claim 2, wherein the spacer comprises one amino acid or 2 to 8 amino acids linked by peptide bond(s). 4. The DDS compound according to any one of claims 1 to 3, wherein the carboxy(C1-4)alkyldextran polyalcohol modified with a saccharide compound is formed by binding a saccharide compound and a carboxy(C1-4)alkyldextran polyalcohol by means of a linker. 5. The DDS compound according to claim 4, wherein the carboxy(C1-4)-alkyldextran polyalcohol modified with a saccharide compound has a cluster modification by saccharide compounds bound by means of a linker. 6. A DDS compound which is obtainable by binding a residue of a drug compound to a carboxy(C1-4)alkyldextran polyalcohol in which a part of carboxyl groups of the carboxy(C1-4)alkyl moiety are modified with a saccharide compound. 7. The DDS compound according to claim 6, which is obtainable by binding the carboxy(C1-4)alkyldextran polyalcohol and the residue of drug compound by means of a spacer. 8. The DDS compound according to claim 6 or 7, which is obtainable by binding the residue of drug compound to the carboxy(C1-4)alkyldextran polyalcohol which is produced by binding the saccharide compound or a linker bound with the saccharide compound to a part of carboxyl groups of the carboxy(C1-4)alkyl moiety of the carboxy(C1-4)alkyldextran polyalcohol. 9. A DDS compound which is obtainable by modifying with a saccharide compound a carboxy(C1-4)alkyldextran polyalcohol in which a residue of a drug compound is bound to a part of carboxyl groups of the carboxy(C1-4)alkyl moiety by means of a spacer. 10. The DDS compound according to claim 9, which is obtainable by binding the carboxy(C1-4)alkyldextran polyalcohol and the saccharide compound by means of a linker. 11. The DDS compound according to claim 9 or 10, which is obtainable by modifying with a saccharide compound a carboxy(C1-4)alkyldextran polyalcohol produced by binding a residue of drug compound to a part of carboxyl groups of the carboxy(C1-4)alkyl moiety of the carboxy(C1-4)alkyldextran polyalcohol by means of a spacer comp