There is no doubt that drug dissolution evaluation is a very important and critical step for the development and assessment of products and will remain so in the future. However, dissolution testing itself will change significantly and dramatically.
The simplification will be reflected by the availability of a very small number of methods, if not only one or two, even for QC purposes. It is important to note that the currently described methods, which are in the hundreds, if not in thousands, will be discontinued as they will not be considered as dissolution methods. These will, in fact, be considered as sets of experimental conditions to show presumed or pre-set dissolution results which will be of limited use. For an appropriate dissolution characterisation of a product the test must be product independent, which is currently not the case.
The test procedures and the apparatuses mostly used, in particular, paddle and basket, are not validated and qualified for their intended use. It is surprising that these apparatuses have been in use for such a long time, however, this practice cannot continue further in a modern and highly regulated and standardized industry such as pharmaceutical, in particular for QC purposes.
It is to be noted that these apparatuses (paddle/basket) cannot be qualified and validated: (1) these apparatuses are inherently flawed because of the poor hydrodynamics within the dissolution vessels hence cannot provide the required repeatability and reproducibility for testing; (2) the stirring/mixing environment within the vessels is such that they cannot simulate the required GI tract physiology appropriately, thus they will never provide physiologically relevant results. Therefore, the use of these apparatuses will be discontinued.
In addition, it should be noted that as the results and conclusions drawn from many years of work are based on the use of these flawed apparatuses, all the observations and claims will require reconsideration.
Considering the above described facts, it should be prudent that one should start preparing for this eventuality of discontinuation of paddle/basket apparatuses.
The good news, however, is that the dissolution characteristics, including the prediction of the plasma drug levels, can easily be determined using a modified approach of Assay and CU determination. For further discussion in this regard, please see the selected links below:
http://www.drug-dissolution-testing.com/?p=1349
http://www.drug-dissolution-testing.com/?p=1328
http://www.drug-dissolution-testing.com/?p=1214
http://www.drug-dissolution-testing.com/?p=1183
