L103- Capsules Flashcards
what are the two main parts of a capsule?
the cap and the body
how many different sizes are capsules available in?
8
what are the different types of capsules?
hard and soft
why do we use HGC over tablets?
- water sensitive
- degrade on compression
where does gelatin come from?
prepared from the hydrolysis of collagen from animals
how are the size of capsules organised?
the smaller the number the larger the capsule
what are gelatine capsules good?
they are non toxic and have a good film and are readily dispersed in body fluids
what is gelatine made from?
84%-90% protein
-3 chains form left hand spiral
what is the difference between hard and soft gelatine
hard gelatine has high bloom.
how are capsules coloured?
using insoluble pigments
-soluble dyes
what are the pigments made from?
titanium dioxide- white
iron oxides- black, red or yellow
how do you fill capsules in a small industrial scale and in hospitals?
use the bench scale
how do you fill capsules in a large industrial places?
industrial scale method, it is all automated
what temperature are gelatine capsules readily soluble at?
37 degrees
what temperature is the HGC insoluble at?
30 degrees
what is the Notes Whitney equation?
dm/dt = DA(Cs-C)/h
what does the Notes Whitney equation show?
dissolution of the powder
why might a drug be relaesed slowly?
- strong compaction
- hydrophobicity of powder contents – lubricants and glidants tend to reduce wetting
what are unconventional capsules?
used mostly for controlled release. they may also have pellets
can liquids be used to fill capsules?
yes, molten liquids which then sets (polymer or lipid ) called solid dispersion, sealed using banding
why should soft gelatine capsules have a moisture level of 13%+?
-otherwise they will be flaking off
what do SGC look like?
commonly seen as ovals and in different colours
why would you use soft capsules?
Avoids handling and compression properties associated with tablets
Improved drug oral bioavailability
Dose uniformity of low-dose drugs
Safety for potent and cytotoxic drugs
Means of formulating liquids, such as oils and low melting- point drugs
why wouldn’t you use soft capsules?
- Specialist equipment required
- increasing cost compared to conventional capsules and tablets
what bloom value are soft gelatine capsules?
low
what should a SGC shell consist of?
- gelatin 40-50%,
- plasticizer (20-30%)
- water (30-40% initially, less than 7% after drying)
how are capsules manufactured?
using rotary die process
what is the rotary die process?
the continuous formation of a heat seal between two ribbons of gelatin, simultaneous with dosing of the fill liquid into each capsule
what types of liquids might not be suitable for SGC?
- liquids that easily migrate through gelatine shell
- anything thing that changes the pH
what materials are used to fill soft capsules?
Water-immiscible (lipophilic) liquids/oils, such as triglyceride oils
Water-miscible (hydrophilic) liquids, such as polyethylene glycol (PEG) 400
Self-emulsifying oils, such as oil+Polysorbate 80
Microemulsion and nanoemulsion systems
Suspensions (Need to consider use of suspending agents)
When are most drugs absorbed best?
after a fatty meal
when will acid soluble drugs dissolve in the body?
in the stomach and will be well distributed through the GI tract
when will acid insoluble drugs dissolve in the body?
they will precipitate in the stomach
what is water immiscible vehicles such as oils?
formulation for Poorly water-soluble drugs often can be dissolved in oil or a mixture of oil and surfactants therefore the drug absorption is enhanced also through lymphatic system.
