Today, the FDA published the final guidance titled “Bioavailability Studies Submitted in NDAs or INDs — General Considerations” (here).  The final guidance comes after the FDA incorporated comments that it received on the draft of the same name issued on February 26, 2019.  That 2019 draft guidance replaced the March 2014 guidance titled “Bioavailability and Bioequivalence Studies Submitted in NDAs or INDs –General Considerations.”  The Agency also included comments that it received on the 2014 document into the 2019 draft guidance.

The FDA says that the final guidance included the following changes from the 2019 draft:

(1)    specifying that individual pharmacokinetic profiles will be considered for products with complex release characteristics

(2)    clarifying that, if the drug labeling specifies that the drug is to be taken with food but does not elaborate on the fed conditions, the sponsor should use a high‑fat meal as the fed condition

(3)    adding statistical approaches for dissolution

(4)    clarifying that enzymes can be added to the dissolution medium to better understand the effect of over‑encapsulation on drug release; and

(5)    removing the ten‑percent alcohol level for dose-dumping studies.

In addition, editorial changes were made to improve clarity.

The 33-page document provides current FDA thinking on the studies that will be expected in investigational and new drug filings to support bioavailability of products.