Baxter Jennifer L, Kukura Joseph, Muzzio Fernando J
Department of Chemical and Biochemical Engineering, Rutgers University, 98 Brett Road, Piscataway, NJ 08854-8058, USA.
Int J Pharm. 2005 Mar 23;292(1-2):17-28. doi: 10.1016/j.ijpharm.2004.08.003.
The USP tablet dissolution test is an analytical tool used for the verification of drug release processes and formulation selection within the pharmaceutical industry. Given the strong impact of this test, it is surprising that operating conditions and testing devices have been selected empirically. In fact, the flow phenomena in the USP test have received little attention in the past. An examination of the hydrodynamics in the USP apparatus II shows that the device is highly vulnerable to mixing problems that can affect testing performance and consistency. Experimental and computational techniques reveal that the flow field within the device is not uniform, and dissolution results can vary dramatically with the position of the tablet within the vessel. Specifically, computations predict sharp variations in the shear along the bottom of the vessel where the tablet is most likely to settle. Experiments in which the tablet location was carefully controlled reveal that the variation of shear within the testing device can affect the measured dissolution rate.
美国药典（USP）片剂溶出度试验是制药行业用于验证药物释放过程和制剂筛选的一种分析工具。鉴于该试验的重大影响，令人惊讶的是，其操作条件和测试装置一直是凭经验选择的。事实上，过去USP试验中的流动现象很少受到关注。对USP装置II中的流体动力学进行检查发现，该装置极易出现混合问题，而这可能会影响测试性能和一致性。实验和计算技术表明，装置内的流场不均匀，溶出结果会因片剂在容器内的位置不同而有很大差异。具体而言，计算预测沿容器底部（片剂最可能沉降的地方）的剪切力会有急剧变化。在片剂位置得到仔细控制的实验表明，测试装置内剪切力的变化会影响所测得的溶出速率。
