The “Paddle over Disk” is a modified version of Method 2 (Paddle Method) and is used for the determination of the drug release rate of transdermal patches. It is described in the United States Pharmacopoeia (USP) under Chapter <724> as Method 5 and in the European Pharmacopoeia (Ph.Eur.) under Chapter 2.9.4. Method 1 as ‘Disk Assembly Method’.