The US Food and Drug Administration (FDA) has published a final guidance regarding bioavailability data that drug sponsors should include with their premarket applications.
BA is defined as the rate and extent to which the active ingredient or active moiety is absorbed from a drug product and becomes available at the site of action. BA data provide an estimate of the amount of the drug absorbed as well as information related to the pharmacokinetics of the drug, the effects of food on the absorption of the drug, and dose proportionality or linearity in the pharmacokinetics of the active moieties.
Bioavailability Studies in NDAs or INDs--General Considerations is a guidance document published by the FDA on 14 April, which outlines the agency's position on the bioavailability data that sponsors should include in investigational new drug (IND) applications and new drug applications (NDA) and NDA supplements.
This guidance provides recommendations to sponsors and applicants submitting bioavailability (BA) information for drug products in investigational new drug applications (INDs), new drug applications (NDAs), and NDA supplements. Also contains recommendations on how to meet the BA requirements set forth in 21 CFR part 320 as they apply to dosage forms intended for oral administration.
The guidance is also applicable to non-orally administered drug products when it is appropriate to rely on systemic exposure measures to determine the BA of a drug (e.g., transdermal delivery systems and certain vaginal, rectal, and nasal drug products).
The guidance provides recommendations on conducting BA studies during the investigational period for a drug intended to be submitted for approval in an NDA and bioequivalence (BE) studies during the postapproval period for certain changes to drug products with an approved NDA.
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