Tablets and capsules Flashcards
What are the advantages of capsules?
1) Increase oral bioavailability
2) Liquids can be orally delivered as a unit
What are the disadvantages of capsules?
1) Specialist manufacturing processes needed
2) Lack of stability
What are the two types of capsules?
Hard and Soft
What type of capsules have hemispherical ends and what is the benefit?
Hard - Resists deformation
What is the composition of hard gelatin capsules?
1) Gelatin
2) Colourants
3) Wetting agents
4) Preservatives
How is gelatin made?
Hydrolysis of collagen
What are the 2 types of gelatin?
1) Type A - Acid hydrolysis of collagen, Pork skin
2) Type B - Alkali hydrolysis, animal bones
Benefits of gelatin
1) Safe - non-toxic
2) Readily soluble
3) Flexiblity
What is bloom strength?
Load in grams required to push required to push a plunger 4nm into a gel, is a quality control technique used for gelatin
What does bloom strength measure?
Strength of gelatin
Hard = greater value
Soft = smaller value
What are the 2 types of colourant?
1) Water soluble dyes
2) Water insoluble pigments
What is used to make capsules opaque?
Titanium dioxide
What is a wetting agent?
Means moulds are lubricated so get an even gelatin capsule
What is the role of preservatives in hard gelatin capsules?
Prevents microbial contamination
What excipients can be used for powder filling of a hard gelatin capsule?
1) Diluents
2)Lubricants
3) Glidants
4) Wetting agents
5) Disintegrants
6) Stabilisers
What does a diluent do?
Increases volume
What is the purpose of a glidant?
Reduce particle friction and increase flow
What is the purpose of a lubricant?
Increases flow by reducing particle friction.
Improves compressibility
What is the purpose of a disintegrant?
Break down the powder
What is the purpose of a wetting agent?
Used when drug is insoluble, Promote increased solubility
Which equation can be used to calculate the dissolution rate of a drug?
Noyes-Whitney:
dm/dt = DA(Cs-C)/h
What is a soft gelatin capsule shell made of?
1) Gelatin
2) Plasticiser
3) Water
4) Flavours, colourants
What arw the advantages of using a soft gel capsule?
1) Increased bioavailability
2) Increased patient compliance
Dose uniformity
What is the key point of soft gel manufacturing?
Rotary die press - dosage the filling of the capsule
What does water immiscible mean?
They wont mix together
What can you fill a soft gel capsule with?
1) Lipophilic
2) Hydrophilic
3) Suspensions
What isn’t suitable to fill a soft gel capsule with?
1) Aldehydes - harden shell, affect dissolution properties
2) Acidic or alkaline solutions
