药品在制片过程中,由于种种原因,造成单个片剂(包括其它固形制剂)含量的不均匀性。这种不均匀性可能给临床疗效带来不同程度的影响,特别是那些治疗量与中毒量极为接近的药品尤为突出。为保证药品的有效性与安全性,对某些主药含量甚少的片剂,更有必要作含量差异检查。目前,对固形制剂含量的均匀性已引起国际上药学界的普遍关注。各国药典亦先后制订了含量差异限度作为控制质量的方法。但各国药典收载品种有较大差异,例如美国药典认为片重差异不是一个控制质量的理 Drugs in the production process, due to various reasons, resulting in a single tablet (including other solid formulations) content inhomogeneity. This inhomogeneity may have varying degrees of clinical effect, especially those with very similar therapeutic and toxic levels. In order to ensure the effectiveness and safety of medicines, it is even more necessary to check the content difference for some tablets with little main drug. At present, the uniformity of the content of the solid preparation has drawn the general concern of the international pharmaceutical community. Pharmacopoeia of different countries also successively formulated the limit of content variation as a method of quality control. However, the pharmacopoeia of different countries have different varieties, for example, the United States Pharmacopoeia that weight difference is not a quality control theory