L54 - Processing of Capsules

• Name 2 types of capsules.

  Regular - hard or soft gelatin.

  
  

  Controlled Release Systems - coated granules/course dispersion.

  
• List some uses of hard shell capsules.

  - Alternative dosage form to tablets.

  
  

  - DPIs.

  
  

  - Filled with beads/pellets/semi-solilf fills.

  
  

  - Good for drugs not suitable for compression

  
• What is gelatin?

  protein derived from collagen in tendons/ligaments/tissues of animals.

  
• How is gelatin produced?

  
  

  Type A/B?

  By partial hydrolysis eg boiling of connective tissue,bones, animal skins.

  
  

  Type A - acid hydrolysis.

  
  

  Type B - base hydrolysis.

  
• Why is gelatin used?


  - Forms strong, transparent gels/flexible films.

  
  

  - Soluble at body temp/in hot water.

  
  

  - Preservatives/jellies.

  
• What's a disadvantage in using gelatin for capsules? (what can occur?)

  Cross-linking- gelatin structure changes and interacts with the drug.

  - Gives more variability in dissolution times of capsules.

  
• How are gelatin capsules prepared?

  - Stainless steel pins dipped into gelatin solution at controlled temps.

  
  

  - Pins withdrawn, rotates and dried.

  
• How are hard vs soft gel capsules made?

  -Hard caps:cap and body fit inside each other.

  -Soft caps:made and filled in one operation eg vit D (not water soluble).
• What does a dosator do?

  
  

  How do they control fill weight?

  
  

  Dose range?

  - Fills gelatin capsules w/ contunuous machines.

  
  

  - Controls fill weight by adjusting powder bed height and dosator pin position.

  
  

  Range = 15-2000mg.

  
• Describe what's added in hard gelatin capsule formation.

  - Uniform capsule filling depends on powder flow.

  -Diluentsbulk up low dose drugs eg lactose, starch, microcsrystalline cellulose.

  -Glidantsegcolloidal silicaandlubricantsegMg stearateadded to decrease friction and improve flow.

  
• What could non-powder fillings include?

  Granules, pellets, tablets, multi-particulates, semisolids, non aq liquids.

  
• What are vegetarian capsules formulated from?

  Two piece capsules formulated from HPMC, starch or PVA.
• List some advantages of soft gelatin capsules.

  - Good for compoundssoluble/dispersiblein oil.

  - Good forcontrolleddelivery/sustained release.

  - Formed, filled + sealed in1 operation.

  -No need to compress; can be used for drugs that can't be compressed.

  - Goodchemical stabilityas oily vehicle protects drugs from oxidation/hydrolysis.

  -No uniformity/powder flow issues.

  
• Give some disadvantages of soft gelatin capsules.

  - Can't incorporate drugs with [high] water conc as this changes phase volume ratio.

  
  

  - Not recommended for O/W or W/O emulsions which become unstable as water is lost.

  
  

  - Surfactants affect capsule seal.

  
  

  - Must avoid pH values <2.5 and >7.5

  
• What does HPMC stand for?

  HydroxyPropyl MethylCellulose