exam revision Flashcards
Delayed Release
products coated and designed to pass through the stomach and only release within the INTESTINAL tract
Extended Release
Products designed to release medication in a controlled manner at a pre-determined rate, duration and location. Helps achieve and maintain optimum therapeutic blood levels of drug
What are the main advantages of Modified Drug release system?
- Less fluctuation in drug blood levels
- Frequency reduction in dosing
- enhanced convenience and compliance
- Reduction in ADRs
- Reduction in overall health cost
What are the disadvantages of Modified drug release?
- loss of flexibility
- dose dumping
- constraints on the types of drugs that suitable for the candidates
- limits the max period (approx. 12 hrs)
What are the 8 extended release technologies?
- Coated beads, granules, microspheres
- Multitablet system
- Microencapsulated drug
- Hydrophilic matrix systems
- Insoluble polymer matrix
- Complex Formation
- Ion Exchange resins
- Osmotic pumps
Delayed release of drug can be intentional till the intestines as it ensures:
- protection of drug from gastric fluids
- reduces gastric distress caused by the drug
- facilitating GI transit for drugs that are better absorbed from the intestines.
What are the 3 dependeds for enteric coating?
- pH
- time
- enzyme
What is repeat action? (Repeatabs)
Initial dose of drug is released immediately and a second dose follows later
What type of condition is repeat action used for?
- chronic conditions that require repeat doses
- Two layers may have one layer for immediate release with a second layer releasing drug later in an extended manner
How are targeted release drugs absorbed?
- colonic drug delivery which are only digested by colonic bacteria.
What are some clinical considerations to consider for modified drug release?
- should not use modified release products interchangeably with immediate release forms of the SAME drug
- patients who are stabilised on modified release product should not be changed as different extended release drugs can have different characteristics
- not to be crushed or chewed
- nasogastric tubes
What is transdermal drug delivery?
passage of therapeutic quantities of drug through the skin and into general circulation
What are the factors affecting percutaneous absorption?
- increase in drug concentration
- larger area of application
- drugs with a MW 100-800 with aqueous and lipid solubility
- has greater physiochemical attraction to the skin than vehicle
- Drugs generally penetrate better in their unionised nonpolar/lipophilic
- duration
- site
What are the advantages of Transdermal Drug Therapy?
- avoids GI drug absorption
- oral route is unsuitable as with vomiting and diarrhoea
- Avoids first-pass effect
- Non-invasive
- extended therapy with single application
- activity of drugs with shorter half-life
- terminated rapidly
- easily and rapidly identified
What are the main disadvantages of transdermal Drug Therapy?
- Relatively potent drugs are suitable due to natural limits of drug entry imposed via skin’s permeability
- Contact dermatitis