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- The pins are withdrawn and rotated around to distribute and cool down the film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