5 - Drug formulation

Question 1

Factors affection pharmaceutical availability (4)

Answer 1

Tablet compression
Excipient - interaction w aqueous GI juices
Form of drug - crystalline or salt
Particle size

Question 2

What is bioequivalence

Answer 2

2 drugs with similar bioavailability (AUC, Cmax and Tmax)

Question 3

What is therapeutic equivalence

Answer 3

2 drugs with similar efficacy and safety at same concentration

Question 4

2 types of insulin injection

Answer 4

Insulin BP
Ultralente insulin

Question 5

Which insulin is short term

Answer 5

Insulin BP
- soluble
- for easier gl levels post prandial

Question 6

Which insulin is long term

Answer 6

Ultralente insulin
- large crystals
- high zinc content
- suspended in solution of sodium acetate
- 36h duration

Question 7

Example of a vehicle in which drug is suspended to affect duration

Answer 7

Thick oil for slow diffusion
Vasopressin tannate in oil for diabetes insipidus

Question 8

What is diabetes insipidus

Answer 8

Lack of ADH (vasopressin)
Excess urine production

Question 9

Why do some local anaesthetics contain adrenaline

Answer 9

To cause vasoconstriction at the site so drug cannot be carried away by circulation

Question 10

Example of controlled release drug

Answer 10

Enteric coating on aspirin
Release delayed until small intestine

Question 11

Criteria for combination products in oral therapy

Answer 11

Frequency of administration of 2 drugs must be same
Fixed doses are optimally effective

Question 12

Adv of combination products (4)

Answer 12

Improved compliance
Ease of administration
Synergistic effects
Decreased adverse effects

Question 13

Example of combination products

Answer 13

Amoxicillin - broken down by beta-lactamase
Clavulonic acid - beta-l inhibitor