Advice and information on all aspects of tablet dissolution testing

Shaft RPM

The USP limit for stirring is ±4% of the set speed of the test. This level of shaft control was set during the early days of equipment manufacturing where surging motors (this temporarily increased or decreased the speed) were difficult to control. All modern equipment can now control the speed to within ±0.5rpm so this problem is rare. However the RPM still needs to be measured periodically with a suitable tachometer.