Zusammenfassung der Ressource
Drug Delivery and Absorption
- Modes of Drug Delivery
Anmerkungen:
- Oral
Pulmonary
Per Rectal
Intravenous
Intramuscular
Trnasfermal
Opthamalic
Subcutaneous
- Relationships
Anmerkungen:
- 1. Most Drugs are weak acid/bases
2. Most drugs are lipophilic
- Cell Membrane
Anmerkungen:
- As usual, made up of phosphobilipid layer
- Factors affecting drug access
Anmerkungen:
- Molecular size and shape
Degree of ionisation
Relative lipid solubility of the ionised and non-ionised forms
Bind affinity to receptor (membrane transport) proteins
Normally, uncharged ones are the ones that are usable due to the affinity to the lipophilic layer.
Extracellular concentration.
- Methods of Traversal
Anmerkungen:
- Pinocytosis
Passive Diffusion
Filtration
Active Transport
- Passive Membrane Transport
Anmerkungen:
- Ionization will affect and influence solublility and hence it is dependent on Ka and local pH
- pH in body
Anmerkungen:
- Urine : 5
Small intestine : 7.8
Duodenum: 6
Saliva: 6
Stomach 1.3
Serum/blood: 7.4
CSF: 7.35
- Henderson-hasselbalch
- Bioavailability
Anmerkungen:
- Degree of a drug becomes available to target tissue after administration
Proportion of the administered dose that reaches the systemic circulation intact