Advanced Drug Delivery Flashcards
What are the ‘musts’ for an effective drug? (2)
- Be pharmacologically active
- To arrive at the right target at the right time
What is a conventional dosage form?
Drug release and drug plasma levels depend solely on the physio-chemical properties of the API
What is a non-conventional dosage system?
Drug release and plasma levels are determined by the technological characteristics of the the formulation (e.g. modified release)
Define drug targeting
To localise and concentrate drugs to the desired therapeutic site, avoiding all other tissues in the body i.e. minimise SE
What is 1st order targeting?
To an organ or tissue i.e. liver targeting
Define 2nd order targeting
To a certain type of cell e.g. tumour cells
Define 3rd order targeting
To an intercellular compartment e.g. lysosomes
What is magic bullet targeting?
Give an example
- API is potent AND selective
- Monoclonal antibodies
What is a prodrug?
Inactive form of drug is activated at the site of action
What is a macromolecular carrier?
A carrier transports the drug to the desired site of action
API is not selective, the carrier is
How can prodrugs be activated at the site of action? (3)
Chemical - conversion by reaction e.g. acid pH –> hydrolysis
Physical e.g. by heat
Enzymatic
What is the rationale behind using prodrugs? (6)
1) Improve permeability through membranes e.g. Dopamine –> Levodopa
2) Site-specific activation (targeting)
3) Increases duration of drug action e.g. if drug is inactivated by metabolic process
4) Decrease toxicity and SE
5) Improve formulation
6) Improve organoleptic properties e.g. taste
What are macromolecule carrier typically formed of?
Polymers
How could a drug be combined with a macromolecule carrier? (2)
- Entrapped in carrier (physical bonds)
- Covalently conjugated
What is a liposome?
Vesicular structures based on one or more lipid bilayer(s) encapsulating an aqueous core
