The harmonized <905> Uniformity of Dosage Units became official on January 1, 2007. Does the harmonized chapter completely replace the current text?
Yes. As of January 1, 2007, only the revised, harmonized chapter text is official. Question: I have heard from European colleagues that existing products may be exempt from the requirements of the harmonized chapter and that it will only apply to new formulations. Will the USP allow such grandfathering? Answer: The harmonized chapter text applies to any monograph, new or existing, that includes a test for Uniformity of Dosage Units. Question: What is the maximum allowable acceptance value for Content Uniformity testing at level 2, where a total of 30 dosage units have been tested? Our confusion is in the use of the L1 and L2 values (15.0 and 25.0, respectively). Answer: Content Uniformity testing can be performed in two stages. The first stage has a total of 10 dosage units tested, and an additional 20 dosage units are tested to complete testing at the second stage. L1 is used as the limit for the acceptance value for both stages of test. L2 is used only in the second stage of testing