Baru Sarn-Ii, Matthews Siobhan, Marchese Eric, Walsh Philip, Coffey Austin
Convergent Technologies Research Group (CTRG), South East Technological University, X91 K0EK Waterford, Ireland.
SCF Processing Ltd., A92 AW74 Drogheda, Ireland.
Polymers (Basel). 2023 Feb 7;15(4):822. doi: 10.3390/polym15040822.
Incorporating thermally labile active pharmaceutical ingredients for manufacturing multifunctional polymeric medical devices is restricted due to their tendency to degrade in the hot melt extrusion process. In this study, the potential of sub- and near-critical carbon dioxide (CO) as a reversible plasticiser was explored by injecting it into a twin-screw hot melt extrusion process of Pellethane thermoplastic polyurethane to decrease its melt process temperature. Its morphological, throughput, thermal, rheological, and mechanical performances were also evaluated. The resultant extrudates were characterised using scanning electron microscopy, parallel plate rotational rheometer, differential scanning calorimetry, thermogravimetric analysis, and tensile testing. The process temperature decreased from 185 to 160 °C. The rheology indicated that the reduction in melt viscosity was from 690 Pa.s to 439 Pa.s (36%) and 414 Pa.s (40%) at 4.14 and 6.89 MPa, respectively. The tensile modulus in the elastomeric region is enhanced from 5.93 MPa, without CO to 7.71 MPa with CO at both 4.14 and 6.89 MPa. The results indicate that the employment of both sub- and near-critical CO as a processing aid is a viable addition to conventional hot melt extrusion and that they offer more opportunities for thermosensitive drugs to be more stable in the molten stream of Pellethane thermoplastic polyurethane.
由于热不稳定的活性药物成分在热熔挤出过程中容易降解，因此将其用于制造多功能聚合物医疗器械受到限制。在本研究中，通过将亚临界和近临界二氧化碳（CO）注入Pellethane热塑性聚氨酯的双螺杆热熔挤出过程中，以降低其熔体加工温度，从而探索了其作为可逆增塑剂的潜力。还评估了其形态、产量、热性能、流变性能和机械性能。使用扫描电子显微镜、平行板旋转流变仪、差示扫描量热法、热重分析和拉伸试验对所得挤出物进行了表征。加工温度从185℃降至160℃。流变学表明，在4. 14 和6. 89 MPa下，熔体粘度分别从690 Pa.s降至439 Pa.s（36%）和414 Pa.s（40%）。在4. 14 和6. 89 MPa下，弹性体区域的拉伸模量从无CO时的5.93 MPa提高到有CO时的7.71 MPa。结果表明，使用亚临界和近临界CO作为加工助剂是对传统热熔挤出的一种可行补充，并且它们为热敏药物在Pellethane热塑性聚氨酯的熔体流中更稳定提供了更多机会。
