为了考察新型可吸收锌合金药物洗脱冠脉支架系统（简称支架）中聚合物涂层的体外降解性能，进行了题示项目的研究。将支架悬吊于50 mL离心管中，用已预热至37℃的10 mL磷酸盐缓冲液浸没，并于37℃振荡。分别在0，7，14，21，28 d时取降解液，用磷酸调节pH至2.8±0.2，经0.20 μm滤膜过滤后采用高效液相色谱法测定，并对降解过程中支架的表观形貌进行观察，进而评估药物涂层的降解情况。结果表明，降解产物乙醇酸和L-乳酸的质量浓度在一定范围内与其峰面积呈线性关系，检出限（3S/N）分别为0.50，0.70 mg·L^-1。对空白加标水样进行精密度试验，相对标准偏差（n=6）为0.12%~2.7%。对空白样品进行加标回收试验，回收率为91.6%~118%。由降解产物的累积量可知，28 d支架中的聚合物涂层基本完全降解。

In order to investigate the in vitro degradation of polymer coating in a new absorbable zinc alloy drug-eluting coronary stent system (stent), the work as mentioned by the title was done. The stent was suspended in a 50 mL centrifuge tube, and 10 mL of phosphate buffer solution preheated to 37℃ was added to immerse the stent, which was shaking at 37℃. On 0, 7, 14, 21, 28 d, the degradation solution was collected, adjusted to pH 2.8±0.2 with phosphoric acid, filtered through 0.20 μm membrane, and determined by high performance liquid chromatography. The morphology was observed to evaluate the degradation of the drug coating. As shown by the results, linear relationships between values of peak area and mass concentration of glycolic acid and L-lacticacid were found in definite ranges, with detection limits (3S/N) of 0.50 mg·L^-1 and 0.70 mg·L^-1, respectively. Test for precision was carried out on blank spiked water samples, with RSDs (n=6) in the range of 0.12%-2.7%. Test for recovery was made on the blank samples by standard addition method, giving results in the range of 91.6%-118%. According to the cumulative amounts of degradation products, the polymer coating in the stent was basically completely degraded in 28 d.