Formulations for Analgesia - Extended Release and Dosage Forms

Question 1

What are the two types of extended release and why are they used?

Answer 1

1. Prompt achievement of plasma concentration of drug remains constant value within therapeutic range for a satisfactory amount of time
2. Prompt achievement of plasma concentration of drug and declines at a slow rate within the therapaeutic range

Question 2

What are sublingual tablets?

Answer 2

Transmucosal delivery in oral cavity

Small/porous fast disintegrating tablet placed under tongue

Question 3

What are dispersible tablets and why are they used?

Answer 3

Useful in patients with difficulty swallowing
Dropped into a glass of water, CO2 liberated
-reaction of carbonate/bicarbonate with a weak acid such as citric acid

Fast disintegration and dissolution of the drug
Buffered water increases the pH of the stomach so faster emptying /shorter residence so reaches the small intestine quicker (main site of absorption)

Question 4

What are suspensions?

Answer 4

Drug in solid phase (powder) suspending in a liquid formulation
A solid in liquid colloid us called a suspension

Question 5

When are suspensions used?

Answer 5

Often in children

Antacids, antibiotics, antifungals, analgesics

Question 6

How can suspensions become unstable?

Answer 6

Flocculation, aggregation (reversible)

Sedimentation and Ostwald ripening

Question 7

What are fast dissolving oral delivery systems?

Answer 7

Solid dosage forms that dissolve rapidly in the oral cavity that results in solution or suspension (no need for water)
Dissolves and disperses in saliva
Potential for increased absorption as portion of drug may be absorbed in mouth, pharynx or oesophagus