Capsules Flashcards
What are advantages of HARD capsules?
- mask unpleasant taste
- Better bioavailability than tablets
- Allow powders to be dispensed in an uncompressed form
What are disadvantages of HARD capsules
- Easily affected by humidity
- Filling speeds of capsule machines are lower than tablet processing
What are the 2 types of gelatin hard capsules
Type A: from pork skins via acid processing
Type B: from bones & animal skins by alkaline processing
How are hard gelatin shells manufactured?
Dip molding process
What are gelatin capsule shell ingredients ?
- Gelatin (25-30%)
- Water
- Colouring agents
- Flavouring agents
- Processing aids (sodium lauryl sulfate)
- Preservatives
Explain hydroxypropyl methylcellulose
- hard capsule
- Plant-based
- non-ionic polymer
- low moisture content
- harder to produce uniform colouring
What number is considered the largest capsule size vs smallest
largest: 000
Smallest: 5
Explain punch method for hard capsules filling technique
- reduce ingredients to fine uniform powder
- mix by trituration
- place powder on a glass slab about 1/3 length of capsule
- fill body by pressing into powder
- fill body 100%
What are common excipients of dry powder capsules (3)
- Fillers (MCC, lactose)
- Disintegrant (croscarmellose, sodium starch glycolate)
- Lubrication (Mg- stearate)
Explain dependent filling methods for capsules
- volume of capsule shell controls the dose
- require the capsule shell to be 100% filled
-Ex. Auger or Screw method
Explain independent filling methods for capsules
- quantity of powder to be filled is measure away from the body
- independent on filling the body 100%
Ex. Dosater method, dosing disc method, vacuum filling method
What is the dosator method suitable for?
- dosing 20mg+
- not suitable for highly cohesive powders
Explain the dosing disc and tamping pins method
Tamping pins are pushed through a powder bed
- suitable for 30mg+ doses
What is the vacuum filling method used for?
low dose inhalation products
Explain liquids and semi-solids filling
- sealing step is required to prevent leakage
- filling using volumetric methods
- EASIER technology than softgel capsules
- liquid excipients
What class drugs do softgels work with?
Class 2 & 4
- low solubility
- filling w liquid is more accurate than powder
What are advantages of softgels?
- Improved drug bioavailability
- increased dose uniformity and reproducibility
- enhanced drug stability
- avoid formation of dust
- oils and low melting point drugs that cannot be compressed
What are disadvantages of softgels?
- subject to the effects of relative humidity
- More expensive, more equipment
- unsuitable for aqueous liquids
What are properties of fill formulation?
- fast and uniform rate of dispersion in the GI tract after softgel shell ruptures
- compatibility with the softgel (pH should be between 2.5-7.5 to not decompose gelatin)
- prevent precipitation of the solubilized drug
- withstand higher temperature from the sealing step (60-70)
Explain when hydrophilic liquids should be used for fill formations of capsules
Example?
- Ethanol and water can be added in the fill matrix below 5-10%
- Problem with drug precipitation when contact with water in the GI tract
Ex. PEG, propylene glycol, glycerin
Example of solution fills for lipophilic liquids
- calcitriol (coconut oil, BHA, BHT)
- valproic acid (corn oil)
Example of suspension fills for lipophilic liquids
- progesterone - prometrium (peanut oil, lecithin)
- ranitidine (triglycerides)
Explain when self-emulsifying agents should be used for fill formations of capsules
Example?
- oil phase and non-ionic surfactants
- spontaenous emulsion formation in the GI fluid stable for longer time
- High surface area provided by the surfactant micelles containing solubilized oil and drug
Ex.
- Ritonavir –> oleic acid, ethyl alcohol, polyoxyl 35 caster oil, BHT)
- Cyclosporin A –> corn oil, ethyl alcohol, linoleoyl macrogolglycerides
What are softgel manufacture methods?
Rotary die process
- requires gelatin mass and fill material to be formulated prior to encapsulation
Seamless (Bubble) process, concentric nozzle dropping, globex method
- gelatin runs through outer nozzle
- fill dispensed from inner nozzle
- produces droplets of fill material in a molten gelatin envelope
