Formulation of cardiovascular drugs Flashcards
What are the cardiovascular conditions that cardiovascular drugs are used for?
- Angina
- Arrhythmias
- Heat failure
- Hypertension
- Lipid regulation
- Myocardial Infarction
- Stroke
What are some of the classes of drugs for hypertension?
- ACE inhibitor
- Angiotensin II receptor antagonists
- Beta receptor blockers
- Calcium channel blockers
- Diuretics
What are the different Glyceryl Trinitrate formulations?
- 300mcg sublingual tablets
- 400mcg metered dose spray
- “5” and “10” patch
GTN is quite volatile, what is done to keep it stabilised and how is it stored?
- Stabilised via Absorbent mannitol and lactose
- Stored:
- Glass bottle (GTN adsorbed via plastic)
- GTN can evaporate from tablets (8 week shelf life)
- Close container, do not transfer containers
- Risk of loss of efficacy if above not followed
What are the advantages of using a GTN spray in terms of shelf life compared to a tablet and patch?
- Tablet (API may evaporate so only 8 week shelf life)
- Spray: lasts years for shelf life
- Patch: lasts 3 years
When using GTN transdermal (prophylaxis), what must you do after applying a new patch?
- Use one per a day and rotate the site of application
2. Due to it making the skin quite sensitive
Describe the structure of a GTN transdermal patch?
- Impermeable tan coloured backing film
- Drug reservoir that contains GTN with lactose
- Semi-permeable release membrane that controls release of GTN to skin
- Layer of silcone adhesive
- White to off white colour protective liner- removed prior to use
What is the rate that a “5” transdermal patch is released at?
Constant rate per cm^2 across the rate limiting membrane- release is proportional to area
What are the different forms of Isosorbide mononitrate you can get?
- Tablets: 10mg, 20mg standard release
- Sprays
- Modified release: lots of different formulations
Describe how a matrix based form of release works?
- Controls rate of access of the environment to the API
- Matrix is solid with pores containing the API
- Hydrophillic
- Hydrophobic- non soluble - Example: Slow K modified release K+Cl- (used to replace lost K+ via diuretics)
- Salt is embedded into wax matrix and leeches out slowly
What form is verapamil available as?
- Injection
- Tablets (f/c)- film coated
- Oral solution
- Sustained release
What is the absorption, bioavailability and half-life of verapamil like?
- 90% good adsorption
- Eliminated by hepatic metabolism
- Leads to relatively low 20% bioavailability
- Half life variable- normally 4 hours (increases in elderly)
What is the dose in Verapamil HCl like?
- 280 to 480mg daily in 2 to 3 divided doses
- Sustained release 240mg daily
- Matrix type sustained release mechanism
