Primer on the Science of In Vitro Dissolution Testing of Oral Dosage Forms and Factors Influencing its Biological Relevance

In vitro dissolution testing can serve as an effective and efficient tool for evaluating the influence of formulation and manufacturing variables on drug release characteristics. The targeted purpose will determine the method used and the implications of the test results. Regardless of its intended purpose, it is necessary to understand the factors influencing in vitro dissolution outcomes to avoid the introduction of error into the data interpretation. This will influence the selection of the in vitro test procedure, ensuring that the method can identify changes in the critical formulation and manufacturing variables. There is also a need to understand the rate limiting factors influencing in vivo product bioavailability both from a dissolution and an absorption perspective. Finally, to achieve in vivo biorelevance, it is necessary to understand how the selected in vitro dissolution test method reflects the variables impacting in vivo product dissolution behavior. This primer summarizes and integrates these diverse variables, fostering an appreciation of the strengths and potential pitfalls that may be encountered during the generation and analysis of in vitro dissolution profiles associated with oral dosage forms. This understanding is needed for developing a well-designed dissolution test procedure that is appropriately fit for purpose.