Bioavailability of a drug is largely determined by the properties of the dosage form, which depend partly on its design and manufacture. Differences in bioavailability among formulations of a given drug can have clinical significance; thus, knowing whether drug formulations are equivalent is essential.
What are three factors that alter 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 is the effect of food on drug bioavailability determined?
Typically, the food effect on the oral bioavailability of the drug is determined in a clinical study conducted with healthy volunteers and in which plasma concentration-time profiles after fasted and fed administration of the test drug are compared on the basis of pharmacokinetic parameters.
