| 摘要 |
The present invention relates to the preparation of enzymatically degradable polymers, having repeating structural unit as shown hereinbelow:X-is selected from phenolic -OH of tyrosine, -OH of serine and threonine and -SH of cysteineY-is pendant group selected from drug molecules containing carboxyl groups,R-is hydrogen, methyl or mixture of hydrogen and methyl on the individual molecule,n-is an integer from 0 to about 100, andm-is an integer from 0 to 10,the said process comprises the steps of reacting diester of poly (oxyalkylene glycol) and hydrochloride of trifunctional amino acid with a dicarboxylic acid in the presence of a condensing agent in a solvent at a temperature in the range of 0° C. to room temperature for a period ranging between 1 hr to 24 hrs, neutralizing the hydrochloride salt by base, and reacting the free amino groups in the side chain of the polymer with the drug molecule containing carboxyl groups to obtain enzymatically degradable polymer.
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