How do you determine bioavailability of a drug?
1 min read
Asked by: Wendy Alderson
For drugs excreted primarily unchanged in urine, bioavailability can be estimated by measuring the total amount of drug excreted after a single dose. Ideally, urine is collected over a period of 7 to 10 elimination half-lives for complete urinary recovery of the absorbed drug.
What factors below determine bioavailability?
Factors which influence bioavailability
- Drug concentration at site of administration.
- Surface area of the absorptive site.
- Drug pKa.
- Drug molecule size.
- pH of the surrounding fluid.
How do you calculate bioavailability percentage?
From an oral dose exposure oral divided by the exposure for the iv dose.
