Friability testing involves repeatedly dropping a sample of tablets over a fixed time, using a rotating drum with a baffle. The result is inspected for broken tablets, and the percentage of tablet mass lost through chipping.
The Tablet Friability apparatus is used for testing. This apparatus consists of a drum of transparent synthetic polymer with polished internal surfaces and is subject to minimum static build-up. One side of the drum is removable. It has a curved projection which extends from the middle of the drum to the outer wall, enabling the tumbling of the tablets at each turn of the drum. The drum is attached to the horizontal axis of a device. It rotates at 25 ± 1 rpm.