intravenous delivery Flashcards
What is drug targeting in therapeutics?
Drug targeting aims for site-specific drug delivery to improve safety, efficacy, and patient compliance by directing drugs to a specific site in the body, reducing side effects.
What are the three levels of drug targeting? and which is the most complicated to perform?
1) Organ level (e.g., liver), 2) Tissue level within the organ (e.g., tumor), and 3) Cellular level (e.g., diseased cells like specific tumor cells).
- cellular level is most complicated
What is the difference between passive and active targeting?
Passive targeting relies on physicochemical properties (e.g., size) and the Enhanced Permeability and Retention (EPR) effect, while active targeting uses receptor-ligand interactions, such as ligands or antibodies, to achieve precise drug delivery.
What is the EPR effect?
The EPR effect allows large particles to accumulate in tumor tissue due to leaky blood vessels, making it useful for passive drug targeting.
what is active targeting?
where receptor interactions are involved in targeting ie ligand or antibody directed drug targeting.
(eg using over expression of folate receptors on tumour cells to facilitate specific uptake.)
What is a key advantage of Drug Targeting Systems (DTS)?
DTS increases the molecular weight of drugs, reducing clearance by the kidneys and liver, resulting in longer circulation times and potentially more effective treatments.
What is a major limitation of DTS?
DTS may struggle to cross endothelial barriers, making it difficult to reach target sites, and can be recognized and eliminated by the immune system.
What are liposomes, and how do they work in drug delivery?
Liposomes are vesicles with one or more lipid bilayers, encapsulating hydrophilic drugs in the aqueous core and lipophilic drugs within the bilayer, used to deliver drugs like anticancer agents.
why are liposomes considered versatile drug carriers?
they have a lipid bilayer and aqueous core. can encapsulate both hydrophilic and hydrophobic drugs.
what are the advantages of conventional liposomes vs tradition i/v treatments?
- low toxicity
- high specificity
- slow release allows recovery of non-lethally damaged non-target cells.
what are the disadvantages of conventional liposomes vs tradition i/v treatments?
- higher cost
- anaphylactic reactions towards liposomes
- can release drug outside target site.
How do stealth liposomes differ from conventional liposomes?
Stealth liposomes have PEG coating to avoid immune detection, allowing longer circulation and more effective passive targeting via the EPR effect.
What are polymeric micelles, and why are they used in drug delivery?
Polymeric micelles are nano-sized particles formed by amphiphilic block copolymers, with a hydrophobic core for drug loading, used mainly for passive targeting due to their stability and high drug loading capacity.
What is an advantage of using polymeric micelles in drug delivery?
They provide high stability and drug loading capacity, protect drugs from aqueous degradation, and avoid immune detection.
What is a limitation of polymeric micelles in drug delivery?
- They have complex synthesis
- limited commercial availability
- unclear drug release mechanisms.
