FDA published as a final guidance Annex 7 to the ICH Q4B Evaluation and Recommendation of Pharmacopoeial Texts for Use in the ICH Regions guideline. As a second revision, Annex 7 focuses on dissolution testing. This annex is one of several pharmacopeial Q4B tests that has been harmonized by the ICH bodies in the US, Europe, and Japan in recent years. In terms of analytical procedures, the annex and FDA guidance say that the European Pharmacopeia 2.9.3. Dissolution Test for Solid Dosage Forms, the Japanese Pharmacopeia 6.10 Dissolution Test, and the US Pharmaceopeia <711> Dissolution, can be used interchangeably in the ICH regions. Some conditions apply according to the guidance. These include: the declaration of interchangeability applies to the Basket Apparatus, the Paddle Apparatus, and the Flow-Through Cell; the dissolution test is not considered to be interchangeable in the ICH regions when enzymes are used in the media; the dissolution apparatus should be appropriately calibrated to ensure compliance with regional GMPs; the test is not considered to be interchangeable in the three ICH regions for dosage forms referred to in the regional compendia as delayed-release, gastro-resistant, or enteric-coated; and finally, validation studies should be conducted to demonstrate that the test results are not adversely affected if the thermometer is to remain in the dissolution vessel per regional GMPs.