soft capsules

Question 1

how are soft capsules made up?

Answer 1

Principal materials: gelatin(Softgels), thermoplastic potato starch (VegaGels)
•Continuous shell surrounding a liquid fill

Question 2

what kind of administration are soft capsules suitable for?

Answer 2

oral- swallow bitten sucked
or inhilation- from cloth/ steam
rectal

Question 3

what does the shape of the soft capsule tell you about it?

Answer 3

the route of admin
round/oval/oblong-oral
torpedo- rectal or vaginal use
tube like- topical

Question 4

what are the advantages of soft capsules compared to tablets?

Answer 4

no compression
optimum uniformity content
longer shelf life for drugs prone to oxidation

Question 5

what is the composition of soft gelatin capsules?

Answer 5

• Higher elasticity than hard capsules and defined viscosity
• Plasticizer (glycerol 15-30 %, often combined with sorbitol or PEG)
• Water (water to dry gelatin1:1)
• Colourants, pigments
• Film coating (enteric coating: 4% cellulose acetate phthalate)•Storage and packaging related to composition of capsule shell

Question 6

what is the composition of Thermoplastic potato starch soft capsules?

Answer 6

• Plasticizer (glycerol, sorbitol, maltitol)
• Anti-caking agent (glycerylmonostearate)
• Water (final equilibrium concentration 30 – 50 %)
• Final protective coating (vegetable wax)

Question 7

what are the two ways you can manufacture soft capsules?

Answer 7

globex method

rotatory die method

Question 8

describe the globex method?

Answer 8

• Lipophilic fill & shell formulation stored in separate containers – both warm (in liquid state)
• Fill and shell material pumped through a double capillary (fill is the inner one)
• Pulsing action to give predetermined fill volumes, separating individual dose units
• The high surface tension gives rise to droplets (reduce surface area) –seamless round capsules
• Capsules fall through immiscible cooling bath (often liquid paraffin, 4 oC)•Capsules collected, washed and dried

Question 9

what do you consider when filling soft capsules?

Answer 9

• When filling - temperature, viscosity, surface activity
• Suspensions
• Pastes
• Oily liquids: vegetable oils, liquid paraffin
• Self-emulsifying systems (poorly water soluble drugs, self emulsify in contact with aqueous media to form fine dispersion e.g. mix of oil, surfactant and co-surfactant
• Liquids miscible with water:PEGs 400-600 (liquid when low mwt)GlycerolIso-propanolTriethylacetateliquid triglycerides

Question 10

what would you consider when filling Solid and semi-solid materials?

Answer 10

Waxes
Triglycerides
Higher molecular wtPEGs
Hydrogenated fatty oils

Question 11

what are the general advantages of filling soft capsules?

Answer 11

• Increased bioavailability of poorly soluble drugs
• Prevention of partial dissolution and re-crystallisation of drugs
• Masking bad taste, odour
• Safe and simple manufacture

Question 12

what are the limitations for filling materials?

Answer 12

• Drugs or excipients containing water or other substances that dissolve gelatinor starch, or change their properties
• Emulsions (o/w or w/o, unstable and will crack during manufacture due to loss of water)
• Surfactants – affect sealing of capsule
• pH limits for gelatin soft capsules

Question 13

what are the ph limits for soft gelatin capsules?

Answer 13

< 2.5, hydrolysis of gelatin– capsules could leak

> 7.5, brown discolouration and reduced solubility of gelatin

Question 14

what is your choice of filling affected by?

Answer 14

for drugs soluble in acidconditions (i.e. stomach):Water miscible filling, drug dissolved or suspended
For drugs practically insoluble in acidconditions: Drug must be dissolved in filling e.g. Improved bioavailability of 20 mg temazepamdose (drug dissolved in PEG)