Verbetering van de biologische beschikbaarheid: bepaling en conceptuele benaderingen bij het overwinnen van problemen met de biologische beschikbaarheid

Bioavailability refers to the amount of unchanged drug reaching the systemic circulation.

Drugs are categorized under the biopharmaceutics classification system into four classes based on their solubility and permeability.

Drug solubility can be determined by pH-solubility profiling and shake-flask or titration methods.

Meanwhile, permeability determination methods include mass-balance pharmacokinetic studies, in vivo intestinal perfusion studies, and permeation experiments with intestinal tissue or epithelial cell monolayers.

Some drugs with low solubility and permeability have poor bioavailability, which can be overcome by pharmaceutical, pharmacokinetic, and biological approaches.

The pharmaceutical approach involves modifying the formulation, manufacturing process, or physicochemical properties without changing the drug's chemical structure.

The pharmacokinetic approach modifies the drug's chemical structure by prodrug designs or developing new chemical entities.

The biological approach involves changing the route of drug administration, such as switching from oral to parenteral routes.