The other day someone indicated that even products of drugs from BCS class II (low solubility and high permeability) have not shown successful IVIVC. These drugs, at least in theory, provide the best case scenario for successful IVIVCs. The question was then asked what may be the reason for such a general lack of success.
For any successful IVIVC one needs to conduct dissolution tests by mimicking the in vivo environment as closely as possible. This is usually done by conducting a dissolution test using water or aqueous buffers having pH in the range of 5 to 7 maintained at 37C. These conditions represent the GI tract (intestinal) environment.
On the other hand, the tests are conducted mostly using paddle and basket apparatuses to simulate mixing and stirring environment. Unfortunately, the stirring and mixing environment of these apparatuses lack simulation of the in vivo environment. In fact, these apparatuses almost provide no stirring and mixing. Therefore, because of this mismatch, one should not expect successful IVIVC. For successful IVIVC, one requires an efficient (gentle but thorough) stirring environment. One such possibility to address this issue may be the use of crescent-shape spindle. For further discussion on the use of crescent-shaped spindle one may search this site or literature in general.
In short, one should not expect success in developing IVIVC using paddle and basket apparatuses.
