Hard-shell Capsules Flashcards
What are the main two parts of a hard-shell capsule?
The cap-Shortest part of capsule
The body- Longest part of the capsule
How do hard-shell capsules prevent contents from being leaked out?
The contents are generally filled into the body before the cap is snapped into place.
What are the advantages of using capsules?
- They have longer shelf life than liquid dosage forms
- Simpiler formulation compared to tablets
- More convinient
- Tampering can be detected easily
- Good absorption profile
What re the two types of gelatin made for hard-shell capsules, and how are they produced?
- Type A gelatin: the type of gelatin is produced through acid hydrolysis ( pH 1-3). The process can take up to 10 days.
- Type B gelatin: This type of gelatin is produced through basic hydrolysis and the process can take up to 3 months.
After the gelatin is hydrolysed, what is it isolated as?
After hydrolysis, gelatin is isolated as a light amber-faintly yellow vitreous (glass-like), brittle, odourless and tasteless solid.
What are the properties of fish gelatin?
Collagen can be extracted from fish.
Skin.bones and fins which are all by-products of the industry
Both cold adn warm fish can be used
What is bloom strength and what is its range in hard-shell capsule?
- Bloom Strength: Provides info on the rigidity of a gelatin gel and corresponds to “ the force (g) needed to depress the surface of a gelatin gel 6.67% (w/w)) aged for 16-18 minutes at 10oC] by 4mm, using a flat bottomed plunger.
- The gelatin used in the manufacture of hard-shell capsules typically has a Bloom strength ca. 230-275 g.
How is viscoity measured with gelatin solution?
Visocisty is typically measured using a U-tube viscometer, again with a 6.67% (w/w) gelatin solution. Values in the range of 3.3-4.7 mPas are used as shell material for hard capsules.
Give 5 properties of gelatin capules?
- Clear, odourless, tasteless, good mechanical properties, readily dissolve in water at body temperature- but will swell and soften in water at room temperature
- Moisture content 13-16%- water acts as a plasticiser, maintaining film flexibility.
- The moisture content will vary in different environments
- Capsults will absorb water in high-humidity environments- The shell will become softer and more malleable
- Capsules will release water in low-humidity environments- Shell will become brittle and more prone to breakage.
Which powders and APIs are incompatible with Gelatin capsules?
Hygroscopic powders, Deliquescent powders, Hydrolysis-prone APIs- API may absorb water from the shell which will affect both drug and capsule integrity.
What is Cross-linking?
Cross-linking is the formation of strong chemical bonds between individual gelatin chains. The formation of those bonds is generally irreversible and can affect the performance of gelatin capsules in pharmacopoeial tests.
What factors cause cross-linking?
- aldehydes and ketones
- oxidising agents
- metal ions
- sugars
- heat
- high/low humidity
- light
What are the consequences of cross-linking?
- Low or incomplete cross-linking
- Delay in capsule disintegration
How may you go about addressing consequnces to do with cross-linking?
You can add protease to the dissolution medium;
Pepsin- mild to moderate cross-linking
Pancreatin- mild cross-linking
What is a sachet?
In terms of drug formulation, sachets will be used to deliver a small quantity of a medicine.
What can you put in a sachet?
Dry solids
- Powders
- Granules
Liquids