我目前的文章中引用率(57次， July 2010) 最高的是这一篇早期的论文。此文阐述了同一个分子但不同晶型可展示完全不同的机械性能。这个工作显示了在发展新药的过程中控制晶型的重要性。

一个较熟悉的类比是碳元素的两个晶型：石墨和钻石。 石墨很软可做很好的润滑剂。 钻石却是自然界中我们所知道的最硬的物质。同样的，若晶型不对，药品的物理性能可能会大大不同，甚至如同两个不同的药物分子一样。一般讲， 若晶体里有滑层 (slip planes) ， 晶体会较软更有可塑性，易变形， 易压片。

目前，我的研究小组正继续测试和发展这个概念。这是我晶体工程学研究的一部分。盼望和有兴趣的学者共同探讨。

Influence of crystal structure on the tableting properties of sulfamerazine polymorphs

C. C. Sun and D. J.W. Grant

Purpose. To understand the influence of polymorphic structure on the tableting properties of sulfamerazine.
Methods. Bulk powders of sulfamerazine polymorph I and of two batches, II(A) and II(B) of different particle size, of polymorph II were crystallized. The powders were compressed to form tablets whose porosity and tensile strength were measured. The relationships between tensile strength, porosity and compaction pressure were analyzed by the method developed by Joiris, E., et al. Pharm. Res. 15:1122–1130 (1998).
Results. The sensitivity of tensile strength to compaction pressure, known as the tabletability, follows the order, I >> II(A) > II(B) and the porosity at the same compaction pressure, which measures the compressibility, follows the order, I << II(A) < II(B). Therefore, the superior tabletability of I over II(A) or II(B) is attributed to its
greater compressibility. Molecular simulation reveals slip planes in crystals of I but not in II. Slip planes provide I crystals greater plasticity and therefore greater compressibility and tabletability. Larger crystal size of II(B) than of II(A) leads to fewer contact points between crystals in the tablets and results in a slightly lower tabletability.
Conclusions. Slip planes confer greater plasticity to crystals of I than II and therefore greater tabletability.