Encapsulation & Capsules Flashcards
What is encapsulation?
Process by which tiny particles/droplets are surrounded by a coating
Properties of nanoencapsulation
- Low payload
- Limited protection/stability
- Highly permeable
Why the need for encapsulation?
- 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
What is macroencapsulation & its use?
Use: Multi-particulate drug delivery system
- Modification of drug release
- Protection of drug (moisture, unpleasant taste, UV)
Advantages:
- High payload possible
- Consistent production quality
What is macroencapsulation & its use?
Use: Multi-particulate drug delivery system
- Modification of drug release
- Protection of drug (moisture, unpleasant taste, UV)
Advantages:
- High payload possible
- Consistent production quality
Advantages of controlled release drug system
- Extended daytime & nighttime activity
- Potential for reduced incidence of side effects
- Reduced dosage frequency
- Increase pt compliance
- Potential lower daily cost
List the available coating process for pharmaceuticals
1) Compression
2) Pan coating
3) Air suspension
4) Spray coating
5) Melt coating
How to make sustained release drug pellet
1) Drug-loaded pellet (Drug layer + Nonpareil bead) aka the core layer is prepared by extrusion-spheronization
2) Coat diffusion barrier polymer layer after
Steps of extrusion-spheronization for production of core layer
1) Dry blending
2) Wet massing
3) Extrusion
4) Spheronization
5) Drying
6) Coating
How to coat pellets with “envelope” air?
Popular: Envelope air spray nozzle
- Shoot air from bottom (Huttlin coating system)
- Shoot air from side (FlexStream coating system)
What’s the purpose of Spray Drying?
To convert solutions/suspensions/emulsions to dry powders
Advantages of Spray Drying
- Highly efficient & versatile
- Reduce volume, liquid to dry form
- Ease dosing, handling & transport
- Improve chemical & biological stability
- Can be established on large industrial scale
Use of Spray Pilling (Congealing)
- Prepare meltable powders (lubricants)
- Taste masking
- Controlled release products
- For food industry usually
Issues with capsules
- Animal protein
- -> Religious sensitivities
- -> May be assoc with animal rights, green-house gas
- Moisture-sensitive
- Properties may change with adsorbed constituents
Fill capacity of capsules
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
Tests for capsule quality
- Assay
- Uniformity of dosage units
- Disintegration
- Dissolution
Advantages of soft gelatin capsules
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
What should NOT be in fill content of softgel capsules
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
Bioavailability from capsules
- 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
