5 - Drug formulation Flashcards
Factors affection pharmaceutical availability (4)
Tablet compression
Excipient - interaction w aqueous GI juices
Form of drug - crystalline or salt
Particle size
What is bioequivalence
2 drugs with similar bioavailability (AUC, Cmax and Tmax)
What is therapeutic equivalence
2 drugs with similar efficacy and safety at same concentration
2 types of insulin injection
Insulin BP
Ultralente insulin
Which insulin is short term
Insulin BP
- soluble
- for easier gl levels post prandial
Which insulin is long term
Ultralente insulin
- large crystals
- high zinc content
- suspended in solution of sodium acetate
- 36h duration
Example of a vehicle in which drug is suspended to affect duration
Thick oil for slow diffusion
Vasopressin tannate in oil for diabetes insipidus
What is diabetes insipidus
Lack of ADH (vasopressin)
Excess urine production
Why do some local anaesthetics contain adrenaline
To cause vasoconstriction at the site so drug cannot be carried away by circulation
Example of controlled release drug
Enteric coating on aspirin
Release delayed until small intestine
Criteria for combination products in oral therapy
Frequency of administration of 2 drugs must be same
Fixed doses are optimally effective
Adv of combination products (4)
Improved compliance
Ease of administration
Synergistic effects
Decreased adverse effects
Example of combination products
Amoxicillin - broken down by beta-lactamase
Clavulonic acid - beta-l inhibitor
