Pharmaceutics

Question 1

List the critical excipients.

Answer 1

Ethanol
Propylene Glycol
Parabens
Benzyl alcohol / Benzoates
Sugar / sweeteners

Question 2

Where are critical excipients often found?

Answer 2

suspension / solutions / injections

Question 3

Importance of powder mixing?

Answer 3

All solid dosage forms require powder mixing for:
Content uniformity.
Therapeutic efficacy.
Patient safety.

Question 4

Challenges of powder mixing?

Answer 4

• Homogeneity difficult to achieve (Especially when mixing small amounts into large bulk)
• Demixing ( Segregation of components overtime.
• Overmixing (Prolonged mixing degrades material properties (e.g. particle size, charge, surface texture).

Question 5

Types of mixtures?

Answer 5

1 -Positive mixture (Mixes spontaneously. )

2 -Negative mixture (Segregates spontaneously.

3 -Neutral mixture (Neither mixes nor segregates spontaneously.)

4 -Perfect mixture (Completely homogeneous. does NOT exist for powder mixtures)

5 -Random mixture (Not completely homogeneous but ‘close enough.’ Very low content variability. Practically indistinguishable from perfect mixtures).

6 -Ordered mixture (Small particles adsorbed onto larger particles. Components move inter-dependently.)

Question 6

What are granules?

Answer 6

• BP 2019 definition: – Preparations consisting of solid, dry aggregates of powder particles sufficiently resistant to withstand handling.
– Intended for oral administration: swallowed, chewed, dissolved or dispersed.
– Types: effervescent, coated, gastro-resistant, modified-release.

simple definition:
• Aggregates of particles. • 200–4000 μm.
• Typical uses:
– 200–500 µm: To make tablets and capsules.
– Over 500 µm: Powder dosage form.

Question 7

pros and cons of granulation?

Answer 7

granulation gives a way for particles in tablet to stay together
Pros • Better handling (e.g. powder flow - bc less SA so less cohesive than separate particles, mixing). • Less likely to segregate. • Better compaction characteristics. • Reduced fines. • Higher bulk density.

Cons • Additional processing steps - more costs.
• Instability during granulation - e.g. wet granulation

Question 8

look at paper flashcards for first powder mixing lectures

Answer 8

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