Mechanical properties and drug loading rate of a polycaprolactone 5-fluorouracil controlled drug delivery system

In the context of precision medicine, controlled drug delivery systems (CDDSs) have become a research focus. The structural integrity of CDDSs is critical for ensuring an acceptable drug release rule; hence, a CDDS must possess appropriate mechanical properties. In this study, a polycaprolactone/5-fluorouracil (PCL/5-Fu) CDDS was fabricated via solvent evaporation, and the effects of the PCL molecular weight and 5-Fu loading rate on the mechanical properties of the CDDS were evaluated. The results of tensile testing, scanning electron microscopy, and substance analysis indicated that when the content of 5-Fu was less than 9.09% in the developed CDDS, 5-Fu was completely compatible with PCL, and no crystal aggregation was induced. In addition, the maximum 5-Fu loading rate required to retain acceptable mechanical properties was 23.08%, and the corresponding tensile strength of the sample was 12.9 MPa. This strength is sufficient to prevent structural failure and instantaneous drug release due to strength reduction during application of the drug delivery system. In-vitro experimental results demonstrated that the PCL/5-Fu CDDS can achieve controlled drug release over 1000 h. These findings provide a basis for establishing a drug release model for the proposed CDDS.