It is often described that one of the purposes, or perhaps the only purpose, of drug dissolution testing is to monitor batch-to-batch consistency in manufacturing processes. I believe that this view is described to maintain the use of dissolution testing based on paddle and basket apparatuses. This view appears to have been out of frustration due to a lack of success with dissolution testing regarding its relevance to a product’s in vivo performance.
The question remains, can the testing be used for the consistency check? The answer appears to be a NO. The testing cannot be used for consistency checks in particular using paddle and basket apparatuses. The reason being that for monitoring the consistency of a product or process, the consistency (reproducibility) of the test itself must be established and known first. Unfortunately, consistency (reproducibility) of the testing based on paddle and basket apparatuses has never been established or available. There are literature reports available that provide a measure of expected variability in dissolution testing. The reported variability values in terms of RSD can be as high as 37% using these apparatuses, with the apparatuses working as expected and meeting the USP specifications. Such high variability in testing instruments is not usually acceptable, as the test would not be capable of providing stringent quality control standards for pharmaceutical products where generally desired variability (RSD) of 10% or less is expected or desired.
Thus, dissolution testing based on paddle and basket apparatuses may not be used for batch-to-batch consistency checks.