Drug dissolution tests are conducted to determine dissolution/release characteristics of a product. Therefore, one requires a pre-established set of experimental conditions (apparatus, rpm, medium volume or pH etc.) independent of the product so that the actual or true characteristics (i.e. dissolution) can be determined.
Current practices in particular using paddle and basket apparatuses, however, require that the analyst MUST first know, or anticipate, dissolution characteristics of the test product, and then ADJUST experimental conditions to achieve the desired or anticipated results. Selections or adjustments of such experimental conditions are then described or promoted, incorrectly, as dissolution method development practices. Almost every product comes with its own set of experimental conditions and expected dissolution results (commonly referred to as Tolerances). At present, one cannot know or determine the actual or true dissolution characteristics of the products. It is, therefore, very important and critical to note that current practices of dissolution testing are practically a complete waste of time and resources.
The suggestion of dissolution testing using the crescent-shaped spindle, along with a single set of experimental conditions (which are product independent as well) addresses the current issues and provides a simple, practical and scientifically valid approach for dissolution testing. For further detail please see these links (1, 2, 3).
