Pharmacokinetics (PK)
Pharmacokinetics studies drug movement through the body, including absorption, distribution, metabolism, and elimination, with applications in drug dosing, schedule optimization, bioavailability assessment, interaction prediction, and drug development.
In vivo PK
- PK in Mice, Rat, Rabbit, Guinea pig
- Oral and Parenteral route
In vitro ADME
- Solubility
- Plasma Protein Binding
- Metabolic Stability
- CYP450 (Inhibition and Induction)
- Permeability
In vivo PK
PK in Mice, Rat, Rabbit, Guinea pig
Pharmacokinetics (PK) studies drug absorption, distribution, metabolism, and excretion in living organisms. It is influenced by physiology in mice, rats, rabbits, and guinea pigs. Factors like administration route, sampling technique, and analytical method are crucial. Allometric scaling is used for extrapolation to humans.
Oral and Parenteral route
Pharmacokinetics studies oral and parenteral drug administration routes, focusing on oral routes for convenience and safety, and parenteral routes for emergencies and professional administration, with oral routes often less than 100% due to first-pass metabolism.
In vitro ADME
Solubility
Solubility is crucial in ADME for oral bioavailability, absorption, and formulation development. Testing methods include kinetic, thermodynamic, shake flask, and pH-solubility profiles. High solubility is preferred, with 0.1 mg/mL being poorly soluble.
Plasma Protein Binding
Plasma Protein Binding is the reversible interaction between drugs and plasma proteins in the bloodstream, affecting drug distribution, efficacy, and clearance, and can be affected by high drug concentrations.
Metabolic Stability
Metabolic stability, measured by liver enzymes and mass balance studies, is a crucial parameter in pharmacokinetics, influencing drug bioavailability, half-life, and dosing frequency.
CYP450 (Inhibition and Induction)
Cytochrome P450 enzymes play a crucial role in drug metabolism, with two regulatory mechanisms: inhibition and induction. Inhibition slows metabolism, increasing plasma concentration and potential toxicity, while induction increases enzyme activity, affecting polypharmacy.
Permeability
Permeability in pharmacokinetics is a drug’s ability to pass through biological membranes, especially the gastrointestinal tract lining, during oral administration, influencing absorption and bioavailability, and requiring specific formulations.
