In vitro–in vivo correlation: Shades on some non-conventional dosage forms

Abstract

In vitro–in vivo correlation (IVIVC) is an important biopharmaceutical tool that is essential during the pharmaceutical development, quality control, and pre- and post-approval changes. IVIVC has been well established for conventional solid oral dosage forms whereby in vitro drug release profiles are usually correlated to in vivo pharmacokinetic parameters. However, there is poor guidance regarding other non-conventional dosage forms. For medicated chewing gums, drug release methodologies were developed, and the results thereof were compared with in vivo chewout studies showing good correlation. Since medicated gums are directly accessible, IVIVC is based on true release data with no interference by absorption phenomena as in the case of orals. Orally inhaled products are different, and IVIVC is challenging. No standardized in vitro drug release testing method exists for testing inhaled products. At this point, aerodynamic particle size measurement (APSD) is the only quality attribute linked to the in vivo performance of the drug product. Alternatively, computational fluid dynamics for the prediction of aerosol deposition within the respiratory tract is used.