关键词：PHA；药物输送；物理化学性质
摘 要：Controlled-release systems have shown several additional advantages over conventional dosage forms, since they are able to improve the temporal and spatial distribution of drugs in the body, reducing the drug degradation under specific physiological conditions and also to improve patient compliance. Due to the high degree of polymerization, biodegradability and biocompatibility characteristics, highly crystalline structure and water insolubility, polyhydroxyalkanoates (PHAs) have received special attention as biomaterials for the preparation of controlled release systems. Depending on the application requirements, different PHAs can be either blended, or have their surfaces modified or combined with other polymers, enzymes or even inorganic materials in order to further improve their mechanical properties or biocompatibility. In this sense, this chapter emphasizes the main physico-chemical processes influencing the drug release rate form controlled release systems so that formulations can be more easily optimized to the intended application, and chemical modifications from polymers may be purposed efficiently.