Drug delivery systems Flashcards
Name the different types of drug delivery systems
Buccal- dissolves under tongue Sublingual- absorbed through cheek Rectal Intravenous Intramuscular Subcutaneous Tablet/capsule Suspension/solution Enteric coated capsule Transdermal Prodrugs Prolonged/ delayed release Inhalation
What are prodrugs?
Inactive forms of the drug, which has to be metabolically activated once administered
What are the advantages of prodrugs?
Avoid degradation in the gut
prolongation of duration of action
What are the advantages of prolonged or delayed release?
maintains drug levels within therapeutic range
reduces need for frequent dosing, which improves compliances of patients and medical staff.
What are the advantages of solutions/suspensions?
Good for patients with swallowing difficulties
Absorbed rapidly
May be given by naso-gastric of PEG tubes
What type of drugs are used in suspensions?
Insoluble or unpalatable drugs
What are the advantages of tablets/capsules?
Easily mass produced
Convenient administration
Accurate doses
Easily reproducible
Why are drugs enteric coated?
To protect the stomach from the toxic drug (e.g. aspirin)
To protect the drug from being dissolved by the stomach acid (omeprazole)
What are the advantages of buccal or sublingual administration?
Avoids first pass metabolism
What are the benefits of rectal administration?
Useful in patients that are unable to swallow
Bypasses pre-systemic metabolism
What are the benefits of intravenous administration?
Rapidly acting
Good for drugs with short half life
Continuous infusion ensures accurate control of blood levels when drug has narrow therapeutic window.
What is the advantage of intramuscular injections?
The allow more sustained duration of action (up to months)
What are the advantages of transdermal?
bypasses first-pass hepatic inactivation
sustained release is possible
What are the advantages of inhaled drugs?
Delivered directly to site of action
Rapid effect
little systemic absorption
