Explanation

polymer synthesized from polyols and diketenes, such as polyorthoester POE synthesized by the addition reaction of 1,6-hexanediol and 2,4,8,10-tetracyclospiro [5.5] undecane, can control the drug release rate by adding acid or base. polyorthoester POE can also be synthesized by polymerization of polyols and orthoesters or orthocarbonates through transesterification. The acid generated from the degradation of these polyesters can catalyze the hydrolysis of ester bonds, and has the function of autocatalytic degradation. It can also be obtained by reacting alkyl orthoesters with ternary alcohols in an anhydrous solvent to obtain a semi solid colloidal substance. Polyorthoester is a hydrophobic polymer, which is stable under alkaline conditions, can be hydrolyzed in acid, has good biocompatibility, and does not cause harmful tissue reactions or systemic reactions. After mixing it with sodium carbonate and norethisterone, it is melted and pressing to form a sheet, which can be made into a base material type drug release system. The acid hydrolysis of linear macromolecular main chain releases the drug. As the drug is released by the etching of hydrophobic polymer heterogeneous phase, it can prevent water from entering the inside of polymer carrier.

Classification