Encapsulation & Capsules

Question 1

What is encapsulation?

Answer 1

Process by which tiny particles/droplets are surrounded by a coating

Question 2

Properties of nanoencapsulation

Answer 2

• Low payload
• Limited protection/stability
• Highly permeable

Question 3

Why the need for encapsulation?

Answer 3

• Protection against moisture, O2 & light
• Provide controlled release of sensitive/reactive material from surrounding/environment
• Mask undesirable taste/odour
• Prolong shelf life
• Improve safety & handling

Question 4

What is macroencapsulation & its use?

Answer 4

Use: Multi-particulate drug delivery system

• Modification of drug release
• Protection of drug (moisture, unpleasant taste, UV)

Advantages:

• High payload possible
• Consistent production quality

Question 5

What is macroencapsulation & its use?

Answer 5

Use: Multi-particulate drug delivery system

• Modification of drug release
• Protection of drug (moisture, unpleasant taste, UV)

Advantages:

• High payload possible
• Consistent production quality

Question 6

Advantages of controlled release drug system

Answer 6

• Extended daytime & nighttime activity
• Potential for reduced incidence of side effects
• Reduced dosage frequency
• Increase pt compliance
• Potential lower daily cost

Question 7

List the available coating process for pharmaceuticals

Answer 7

1) Compression
2) Pan coating
3) Air suspension
4) Spray coating
5) Melt coating

Question 8

How to make sustained release drug pellet

Answer 8

1) Drug-loaded pellet (Drug layer + Nonpareil bead) aka the core layer is prepared by extrusion-spheronization
2) Coat diffusion barrier polymer layer after

Question 9

Steps of extrusion-spheronization for production of core layer

Answer 9

1) Dry blending
2) Wet massing
3) Extrusion
4) Spheronization
5) Drying
6) Coating

Question 10

How to coat pellets with “envelope” air?

Answer 10

Popular: Envelope air spray nozzle

• Shoot air from bottom (Huttlin coating system)
• Shoot air from side (FlexStream coating system)

Question 11

What’s the purpose of Spray Drying?

Answer 11

To convert solutions/suspensions/emulsions to dry powders

Question 12

Advantages of Spray Drying

Answer 12

• Highly efficient & versatile
• Reduce volume, liquid to dry form
• Ease dosing, handling & transport
• Improve chemical & biological stability
• Can be established on large industrial scale

Question 13

Use of Spray Pilling (Congealing)

Answer 13

• Prepare meltable powders (lubricants)
• Taste masking
• Controlled release products
• For food industry usually

Question 14

Issues with capsules

Answer 14

• Animal protein
• -> Religious sensitivities
• -> May be assoc with animal rights, green-house gas
• Moisture-sensitive
• Properties may change with adsorbed constituents

Question 15

Fill capacity of capsules

Answer 15

Common: Size 1 (0.48) & 0 (0.67)

• Can have self-locking mechanism
• Capsule filled wt = [Tapped density] x [Capsule vol]
• Good fill depends on good flow properties of feed

Question 16

Tests for capsule quality

Answer 16

• Assay
• Uniformity of dosage units
• Disintegration
• Dissolution

Question 17

Advantages of soft gelatin capsules

Answer 17

1) No compression stage (can contain poorly compressible drug)
2) Liquid fill avoids powder flow & mixing problems
3) Avoid O2/moisture degradation of drug
4) Good for poorly water-soluble drugs

Question 18

What should NOT be in fill content of softgel capsules

Answer 18

1) Emulsions (may crack)
2) [High] surfactants, affect gelatin integrity
3) pH < 2.5: Hydrolysis of gelatin
4) pH > 7.5: Tanning effect on gelatin, insolubility
5) Aldehydes, cross-linking, tanning effect

Question 19

Bioavailability from capsules

Answer 19

• Dissolution of gelatin shell quickly disperses content into GIT
• Discharge of capsule content depends on the flow of materials
• -> Problematic for hydrophobic materials
• -> Can add surface active agent to aid wetting, discharge