Drug dissolution testing is an important and critical technique for developing and evaluating the quality of a drug product based on its release characteristics in vivo i.e., in the human GI tract, in particular the small intestine.
Often dissolution studies are conducted using paddle and basket apparatuses. However, testing using these apparatuses has shown significant frustrations in obtaining relevant results with acceptable variability (reproducibility).
Significant literature is available describing the flaws of these two apparatuses. One such flaws is that, although generally assumed, these apparatuses have never been validated for their intended purpose i.e., obtaining relevant and reproducible results.
Even though these flaws are generally recognized, these apparatuses are in use as a “tradition” because these are the ones most commonly suggested and employed in the past. Another reason of their continued use is an apparent and unfortunate twist in the objective of the dissolution testing. That is, rather than evaluating dissolution characteristics of a product, it is often suggested to establish the experimental conditions that show the desired dissolution characteristics. Thus, there is a large waste of human and financial recourses in developing drug and product dependent procedures.
The practice of obtaining or showing the desired and product dependent dissolution results has no purpose other than rationalizing the continued use of paddle and basket apparatuses.
To conduct appropriate dissolution studies, one needs to focus on the true objective of the testing i.e., to observe drug dissolution/release characteristics of a product in vivo. With this objective things will start to fall in place. This will allow the analyst to use more efficient apparatuses and simple experimental conditions to obtain useful results.
