The use of polymers as excipients for drug delivery has afforded stable formulations that reliably control the release of active pharmaceutical ingredients (APIs). While many materials are available and used, few polymers exhibit the numerous advantages, including amorphous characteristics, noninflammatory properties, and resorbable degradation products, like those of poly(ester urea)s (PEUs). Furthermore, stability issues that arise in various APIs can make formulation optimization difficult. Herein, a series of PEUs were synthesized that vary by the fraction of l-phenylalanine monomer incorporated into the copolymerization. The various PEUs and entecavir monohydrate were dry-mixed at different weight percentages (15, 30, and 50%). Filaments of the PEU formulations were extruded and analyzed quantitatively for drug loading and content uniformity by using μ-CT and UPLC analysis. Drug dissolution profiles from filament segments were monitored over a 4-week period and ultimately showed that the controlled release of entecavir was influenced by the incorporation of the l-phenylalanine within the polymer.

中文翻译：

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基于氨基酸的聚（酯脲）作为恩替卡韦缓释的基质。

使用聚合物作为药物传递的赋形剂，可提供稳定的制剂，可可靠地控制活性药物成分（API）的释放。尽管有许多材料可供使用，但很少有聚合物表现出许多优点，包括无定形特性，非炎性特性和可吸收降解产物，例如聚（酯脲）（PEU）。此外，各种API中出现的稳定性问题可能会使配方优化变得困难。本文中，合成了一系列PEU，其随并入共聚反应的1-苯基丙氨酸单体的比例而变化。将各种PEU和恩替卡韦一水合物以不同的重量百分比（15％，30％和50％）干混。挤出PEU制剂的长丝，并通过μ-CT和UPLC分析定量分析药物载量和含量均匀性。在4周的时间内监测了来自细丝段的药物溶出曲线，最终表明恩替卡韦的控制释放受1-苯丙氨酸在聚合物中掺入的影响。