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
Gelatinprotein, prepared from hydrolysis of collagen (animal
bones and skin) type A : pI = 7-9, pig skin type B : pI = 5, animal bones
possesses 4 essential properties
• stable when dry• subject to microbial degradation when moist• Digested• absorbed
Hard Gelatin Capsulescontain 12 - 16 % moisturetypically filled with dry solids
powders granules pellets tablets
also contain colorant preservatives SIZE VOLUME (cm3)
000 1.3700 0.950 0.681 0.502 0.373 0.304 0.215 0.13
Manufacture
Capsule Filling
Fillingoperations involved
rectification of empty capsules separation of caps from bodies filling capsule bodies replacing caps and ejecting filled capsules
3 basic methods for powder filling auger or screw dosator dosing disc
Capsule Filling auger
• semi-automatic operation• filling based on volume• need good powder flow properties
Dosator• fill based on weight• continuous operation
Capsule Filling dosing disc
• filled based on weight• continuous operation
Bioavailabilityfactors which influence bioavailability
Hard Gelatin CapsulesAdvantages
tasteless and odorless swallowing is easy flexibility in formulating uniquely suitable for blinded clinical trials useful for extemporaneous compounding by pharmacist
Disadvantages tend to be more expensive to produce than tablets not suitable for highly soluble salts
Soft Gelatin Capsules (Softgels)• 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
Manufacture
Bioavailability
Soft CapsulesADVANTAGES
may contain liquids, suspensions, pastes rapid release of contents useful for drugs prone to oxidation
DISADVANTAGES have a greater tendency to adhere to each other more expensive increased possibility of interactions between drug and shell
