Tablets are classically tested according to the USP 2 paddle method. Swelling or floating dosage forms such as capsules are tested according to USP 1 basket method. USP 5 (paddle-over-disk) and USP 6 (rotating cylinder) are used for transdermal dosage forms.

To benefit from complete flexibility on media volumes and to reproducibly position dosage forms, the right method is the USP 4 flow-through cell.