Wobble

The USP limit for wobble is ±2mm. If there is significant wobble it can increase the dissolution rate by about 8% for paddles and 5% for baskets (2mm wobble). The wobble can be caused by a bent or loose shaft or a misshapen basket. The easiest way to check for wobble is by eye (2mm will be easily seen) but it should be quantified by a suitable tool. To check shaft straightness simply roll the shaft over a bench top — it should roll smoothly and not stick up at the end. Wobble can be kept to a minimum by handling the baskets and shafts with care — they should be kept in proper holders rather than just collectively in a drawer.