Yang L, Venkatesh G, Fassihi R
Department of Pharmaceutical Sciences, School of Pharmacy, Temple University, Philadelphia, PA 19140, USA.
J Pharm Sci. 1996 Oct;85(10):1085-90. doi: 10.1021/js960039v.
Poly(ethylene oxide) polymers (PEO) appear to have great potential for controlled release applications. These polymers are hydrophilic with good water solubility, low toxicity, and high swelling capacity. As part of formulation optimization for a large-scale solid dosage form production, physicomechanical characterization of PEO was undertaken using a compaction simulator. Heckel plots for all PEOs were constructed, and yield pressures (Py) at different punch velocities were calculated from the linear portion of the plots. Low Py values, increase of Py with increasing punch speed, upward curvature of the plot, and strain rate sensitivity values indicate that the densification process and consolidation mechanism for PEOs of various molecular weights (0.2 x 10(6) to 7 x 10(6)) are identical and follow plastic deformation. PEOs have a high degree of crystallinity (57-85%) and show significant axial recovery (15-25%) upon decompression and ejection. The low Py values (58-78 MPa) and low mean compaction pressures demonstrate that volume reduction (compressibility) under pressure is excellent. However, due to viscoelastic behavior and large axial expansion, tablets of relatively low tensile strength are produced. These observations suggest the need to blend PEO with highly compactible excipients in order to produce tables on a high-speed production press.
聚环氧乙烷聚合物（PEO）在控释应用方面似乎具有巨大潜力。这些聚合物具有亲水性，具有良好的水溶性、低毒性和高溶胀能力。作为大规模固体剂型生产配方优化的一部分，使用压实模拟器对PEO进行了物理机械表征。构建了所有PEO的Heckel图，并从图的线性部分计算了不同冲头速度下的屈服压力（Py）。低Py值、Py随冲头速度增加而增加、图的向上曲率以及应变速率敏感性值表明，各种分子量（0.2×10⁶至7×10⁶）的PEO的致密化过程和固结机制是相同的，并且遵循塑性变形。PEO具有高度结晶度（57 - 85%），在减压和弹出时表现出显著的轴向恢复（15 - 25%）。低Py值（58 - 78 MPa）和低平均压实压力表明压力下的体积减小（可压缩性）非常好。然而，由于粘弹性行为和较大的轴向膨胀，会生产出拉伸强度相对较低的片剂。这些观察结果表明，需要将PEO与高度可压实的辅料混合，以便在高速生产压片机上生产片剂。
