1. Absorbtion of Bioactive Compounds
Absorbtion from GI tract

2. Certain ionic compounds may go thru as ion-pair
Crossing the membrane
Passive transport / diffusion
Rate  Conc. absortion site (1. order kinetics)
% Drug absorbed  lipophilicity
Size of molecule
Certain ionic compounds may go thru as ion-pair

3. Active transport / Carrier mediated transport
Less common
Structural recemblanse with for instance nutritional compound
Transport against conc. gradient
Mechanism saturated at high conc.
Competition for carrier molecules, compounds with structural resemblance

4. logP - P: Partition coefficient between n-octanol and water
Most drugs: Passive diffusion
Low lipophilicity unionized form - low absorbtion
logP - P: Partition coefficient between n-octanol and water

5. Bad kinetics -- Need for improved structure
Pharmacokinetics
Mathematic descript. of A) Biolog. processes affecting drugs
B) Biolog. processes affected by drugs drugs
Mathematical expressions to describe temporal changes in drug conc.
Determine constrains related to ADME processes
Optimal dossage regime
(how much drug, how often etc.)
Bad kinetics Need for improved structure

6. The terapeutic window Min. tox. conc (MTC) Min. effective conc (MEC)
Therapeutic index = TD50 : ED50
Window size - Disease severity

7. Compartment models Two compartment model One compartment modell
The whole body = central compartment
Drug rapidly distributed thru out the body
Central compartment (plasma etc)
Peripher compartment (certain tissue, organs etc)