Türesin F, Gürsel I, Hasirci V
Health Sciences Centre, Gastrointestinal Sciences, Calgary, AB, Canada.
J Biomater Sci Polym Ed. 2001;12(2):195-207. doi: 10.1163/156856201750180924.
Various random copolyesters of 3-hydroxybutyrate and 3-hydroxyvalerate (PHBV) and 3-hydroxybutyrate and 4-hydroxybutyrate P(3HB-4HB) were used in the construction of biodegradable, implantable rods for the local delivery of antibiotics (Sulperazone and Duocid) in chronic osteomyelitis therapy. Drug loading, type of active agent, and additional coating of the implant surface all have significant contributions to the in vitro release profile. The rate and duration of Sulperazone release from P(3HB-4HB) rods were controlled by the polymer/drug ratio (drug loading). The rate of drug dissolution was substantially higher than that of polymer degradation. Therefore, the release phenomenon was more dependent on drug dissolution rather than on polymer degradation or diffusion. Coating rods with the same type of polymer substantially reduced the initial burst effect observed with the uncoated rods, and significantly decreased the release rate so that the release kinetics became almost zero order. Antibiotic release from coated rods was sustained for over a period of 2 weeks at a constant rate, whereas uncoated rods released their contents in less than a week. Impregnation of Duocid into the hydrophobic polymer matrix yielded a rod with a smoother surface topography. The release from these rods was significantly higher than for rods loaded with Sulperazone and a zero order release could not be obtained with these samples.
3-羟基丁酸酯与3-羟基戊酸酯的各种无规共聚酯（PHBV）以及3-羟基丁酸酯与4-羟基丁酸酯的共聚酯P(3HB-4HB)被用于构建可生物降解的植入棒，用于在慢性骨髓炎治疗中局部递送抗生素（舒普深和杜克洛）。药物负载量、活性剂类型以及植入物表面的额外涂层对体外释放曲线均有显著影响。舒普深从P(3HB-4HB)棒中的释放速率和持续时间由聚合物/药物比例（药物负载量）控制。药物溶解速率显著高于聚合物降解速率。因此，释放现象更多地取决于药物溶解，而非聚合物降解或扩散。用相同类型的聚合物包覆棒材可大幅降低未包覆棒材所观察到的初始突释效应，并显著降低释放速率，使得释放动力学几乎变为零级。包覆棒材中的抗生素以恒定速率持续释放超过2周，而未包覆棒材在不到一周的时间内就释放完了其内容物。将杜克洛浸渍到疏水性聚合物基质中得到了表面形貌更光滑的棒材。这些棒材的释放量显著高于负载舒普深的棒材，并且这些样品无法实现零级释放。
