Background: Generic products must be bioequivalent to the innovator brand product. Nevertheless, in addition to meeting bioequivalence standards, attention must be paid to the content of the active substance and contaminants in generic drugs.

Objectives: This study compared the pharmaceutical quality of four generic losartan potassium formulations with the brand-name product: Cozaar®.

Methods: The United States Pharmacopeia (USP) losartan potassium standard was used as reference material. The products tested (all 50 mg formulations) included four generic tablet formulations and the innovator brand product Cozaar®. Active substance content, organic impurities, and elemental impurities were assessed following the USP monograph for losartan potassium tablets and USP Chapter <233> on Elemental Impurities.

Results: The results showed that three of the four generic products had low content of the active ingredient. The values ranged from 86.4 to 93.8%, being acceptable not below 95% of the labeled amount. Organic impurities were not detected in any of the products, and of the 13 elemental impurities tested, only four elements were detected. The elemental impurities Cr, Ni, Cu, and As were, however, in amounts within the limits established by the USP monograph. The only concern on the generic drugs analyzed was the low content of the active ingredient in 75% of the products.

Conclusion: Since losartan is a drug of continuous use, lower content of the active ingredient may go unnoticed by the users of the generic product and entailed clinical consequences during long-term therapy.

背景：通用产品必须与创新品牌产品具有生物等效性。但是，除了要达到生物等效性标准外，还必须注意仿制药中活性物质和污染物的含量。

目的：本研究比较了四种通用氯沙坦钾制剂与品牌产品Cozaar®的药物质量。

方法：以美国药典（USP）氯沙坦钾标准品为参考材料。测试的产品（所有50 mg制剂）包括四种通用片剂和创新品牌产品Cozaar®。活性物质含量，有机杂质和元素杂质的评估遵循美国药典关于氯沙坦钾片的专论和关于元素杂质的美国药典第<233>章。

结果：结果显示四种通用产品中的三种具有较低的活性成分含量。该值在86.4至93.8％的范围内，可接受但不低于标记量的95％。在所有产品中均未检测到有机杂质，在所测试的13种元素杂质中，仅检测到4种元素。但是，元素杂质Cr，Ni，Cu和As的含量在USP专论确定的范围内。所分析的仿制药唯一需要关注的是75％的产品中活性成分含量低。

结论：由于氯沙坦是一种连续使用的药物，因此该仿制药的使用者可能不会注意到有效成分的含量较低，并且在长期治疗期间会产生临床后果。