Transcript week07.1.capsules 2004

CAPSULES
solid dosage form
 the drug is enclosed within either a hard or soft
shell


shell is typically made of gelatin
primarily intended for oral delivery
 provide a rapid release of contents

CHEE 440
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Gelatin

protein, prepared from hydrolysis of collagen (animal
bones and skin)
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possesses 4 essential properties

stable when dry
subject to microbial degradation when moist
digested and absorbed
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CHEE 440
type A : pI = 7-9, pig skin
type B : pI = 5, animal bones
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Hard Gelatin Capsules
contain 12 - 16 % moisture
 typically filled with dry solids

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contain
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CHEE 440
powders
granules
pellets
tablets
colorant
preservatives
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Hard Gelatin Capsules
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come in 2 sections - body and cap
may be colored
may have a tamper-proof band
can be self-locking (ex. Coni-Snap)
come in varying sizes
SIZE
000
00
0
1
2
3
4
5
CHEE 440
VOLUME (cm3)
1.37
0.95
0.68
0.50
0.37
0.30
0.21
0.13
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Manufacture
CHEE 440
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Filling

operations involved
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3 basic methods for powder filling
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CHEE 440
rectification of empty capsules
separation of caps from bodies
filling capsule bodies
replacing caps and ejecting filled capsules
auger or screw
dosator
dosing disc
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Capsule Filling


CHEE 440
auger
» semi-automatic operation
» filling based on volume
» need good powder flow
dosator
» fill based on weight
» continuous operation
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Capsule Filling

CHEE 440
dosing disc
» filled based on weight
» continuous operation
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Bioavailability

factors which influence bioavailability
 disintegration rate
» at body T, gelatin dissolves
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CHEE 440
drug particle size
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Factors Influencing Bioavailability

concentration of lubricants and glidants
packing density of
powder

CHEE 440
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Hard Gelatin Capsules
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Advantages
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Disadvantages
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CHEE 440
tasteless and odorless
swallowing is easy
flexibility in formulating
uniquely suitable for blinded clinical trials
useful for extemporaneous compounding by pharmacist
tend to be more expensive to produce than tablets
not suitable for highly soluble salts
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SOFT GELATIN CAPSULES

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

CHEE 440
consist of a continuous gelatin shell surrounding a liquid
core
formed, filled, and sealed in one operation
shells are softened by addition of glycerin or polyhydric
alcohol (ex. sorbitol)
oblong, spherical, elliptical in shape
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Soft Capsules

fill material

liquids are limited to those which do not affect capsule shell
» water-immiscible
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vegetable oils, mineral oil, triglycerides
» water-miscible, nonvolatile
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CHEE 440
PEG 400 and 600
must flow under gravity at 35 C or less
shell provides a good barrier to oxygen and contains little
residual water (7-10%)
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Manufacture
CHEE 440
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Bioavailability
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CHEE 440
rapid absorption, typically as good as liquids
better than tablets
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Soft Capsules
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ADVANTAGES
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DISADVANTAGES
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CHEE 440
may contain liquids, suspensions, pastes
rapid release of contents
useful for drugs prone to oxidation
have a greater tendency to adhere to each other
more expensive
increased possibility of interactions between drug and shell
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