May 9th, 2011 | Author: Saeed Qureshi
Bio-relevant dissolution tests are highly desirable and are often referred to. It appears that such tests are commonly understood as intuitive expectations rather than a clearly defined scientific objective. This creates confusion, misunderstandings and leads to a lack of progress in this regard. To avoid such confusion, the following may be considered as an appropriate definition:
“A bio-relevant dissolution test is a test which is conducted using experimental conditions representing GI tract environment, in particular intestinal, and capable of predicting in vivo response comparable to the actual blood concentration-time profiles obtained from the bioavailability/bioequivalence studies.”
It is essential to understand that a bio-relevant test must be conducted using appropriate and bio-relevant experimental conditions. Use of non-physiological test conditions such as de-aeration of dissolution medium, product dependent experimental conditions, inefficient or lack of stirring/mixing within dissolution vessels, etc., are to be avoided. Furthermore, the test conducted with appropriate test conditions must also be able to predict in vivo (blood) drug concentration-time profiles. For example, the predicted profiles should at least be able to differentiate between fast (e.g., IR) and slow-release (ER) products, as these would be from an in vivo study. Such a test should then be used to evaluate the potential drug release characteristics of a test product. For further discussion of the subject and detailed methodology to calculate drug concentration-time profiles from dissolution results, please see the links (1, 2).