Capsules Flashcards
What are capsules?
Solid dosage forms in which the drug substance and/or excipients are enclosed within a soluble container or shell or coated on the capsule shell. The shells may be composed of two pieces (body and cap) or a single piece
What are the shell materials?
Gelatin: traditional polymer for capsules
Hydroxypropyl methylcellulose: plant based material
What are the advantages of hard capsules?
- Mask unpleasant taste and odor of drug
- better bioavailability
- allow powders to be dispensed in an uncompressed form
- versality for multiple filling formulations
- may be easier for some people to follow
What are the cons of hard capsules?
- easily affected by humidity
- might not be easy for some people to swallow
- filling speed of capsule machines is slower than tablets
- can be tampered
- not compatible with certain materials
- cost of capsule shells and manufacturing
What are the properties of gelatin?
- produced by hydrolysis of collagenous materials
- moisture content is 13-16%
- produces strong flexible film
- consistent dissolution
- cross linking can happen and modify dissolution
- mechanical stability depends on water content
Type A - pork skins via acid processing
Type B - bones and animal skins by alkaline processing
What are the gelatin capsule shell ingredients?
Gelatin, water, colouring agents, flavouring agents, processing aids (SLS), preservatives (parabens)
What is the dip molding process?
- Pair of dipping pins put inside a warmed, aqeuous gelatin solution to form a film around the pins
- The pins are withdrawn and rotated around to distribute and cool down the film
- dried film is removed and cut to length
- two parts are joined to the pre locked position
What are the properties of HPMC?
- plant origin, non ionic polymer
- immediate or modified release
- low moisture content (2-9%)
- consistent dissolution with no cross linking
- great physical stability (break less in dry conditions)
- prepared by dip molding process or thermogellation
- rough capsule surface
- harder to produce uniform colouring
What are the hard capsule fillings?
Dry powders, pellets, granules, tablets, semi solids, non aqueous liquids
What are the two filling methods for extemporaneous compounding?
- punch method (hand filling)
- capsule filling machines
What are the packing stats? What is the procedure?
- how much powders fits into the capsule
- capsule body is 100% filled
- capacity is dependent on the density of the powder
- determines capsule size needed
- Tare the weight of an empty capsule shell
- Fill 5 capsules with each ingredient
- Weigh each filled capsule and get an average
- Record the weight for that capsule size to obtain the packing stats for the individual ingredient
What are the filling step requirements for industrial methods?
powder flow, lubricity, compressibility (carr’s index 18-35)
What are the common excipients of dry powder capsules?
Fillers (MCC, Lactose), Disintegrant (Croscarmellose, sodium starch glycolate), Lubricant (Mg stearate)
What are the dependent methods?
Volume of capsule shell controls the dose
Requires it to be 100% filled for correct weight uniformity
Auger or screw method
What are the independent methods?
Dosator, dosing disc and vacuum filling
Dosator - suitable for >/= 20 mg, not suitable for highly cohesive powders
Dosing disc - >30 mg
Vacuum filling - low dose inhalation products
What are the liquid and semi solid fillings?
- sealing step required
- easier tech than softgel capsules
Excipients:
Lipophilic - vegetable oils, esters, fatty acids, fatty alcohols
Hydrophilic: PEG 3000-6000
Amphilic: poloxamers, lecithin, PEG esters
What are soft gels?
A liquid or semi solid matrix inside an one piece plastizicized gelatin shell
What are the pros of soft gels?
- improved drug bioavailability
- increased dose uniformity and reproducibility
- easy to swallow, lack of odour and taste
- avoid formation of dust
- oils and low mp drugs that cannot be compressed
- enhanced drug stability
what are the cons of softgels?
- subject to effects of humidity (8-16%)
- difficult for some people to swallow
- more expensive, specialized equipment, formulation optimization requires more expertise
- drugs can migrate from oily vehicle into shell
- unsuitable for aqueous liquids
What are the softgel shell ingredients?
gelatin (type B), water, plasticizers (glycerin, propylene glycol, sorbitol), preservative, colour and opacifier
What are the properties of fill formulations?
- capacity to dissolve the drug dose in small volume
- fast and uniform rate of dispersion in the GI tract
- compatibility with softgel (pH shoild be 2.5 to 7.5)
- prevent precipitation of solubilized drug
- withstand high temp during sealing step (60-70)
what are the types of fill formulations?
solutions, suspensions, emulsions, microemulsions, self emulsifying drug delivery system, self microemulsifying
What are the hydrophilic liquids?
PEG 400 and 600, propylene glycol, glycerin
Ethanol and water below 5-10%
Problem with drug precipitation when it contact with water in GI tract
Examples: Ibuprofen, Naproxen sodium, Nifedipine
What are the lipophilic liquids?
tryglyceride oils
solution fills: calcitriol, valproic acid
suspension fills: progesterone, ranitidine
