Solid Oral Dosage Forms 3 Flashcards Preview

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Flashcards in Solid Oral Dosage Forms 3 Deck (16):

Why do we use a tablet coating?

Protect API from light and moisture
Mask flavour of bitter API
Mask colour variation of raw materials
Improve patient compliance by producing products with good appearance
Aid product identification
Aid high-speed packaging
Coatings can add functional characteristics to release


Types of coating

Film coating- most used process
Sugar coating- traditional method, widely used in confectionary industry
Press coating- minor method, increasing interest as used to manufacture complex release forms


Tablets for coating

Tablets produced to coating called the core
Robust enough to survive extra handling involved in coating process
Strong cores made, especially for film coating, using excipients producing tough compact e.g. microcrystalline cellulose adds plastic component to formulation


Film coating

Application of thin polymer film to tablet surface, film must be strong enough to withstand mechanical handling
Film coating solution consists of film forming polymer, plasticizer, colorants and solvents
Polymers- non-release modifying, release modifying


Comparison of film and sugar coating

Film coating: c. 2% weight gain, formulation: polymer, plasticizer and colorants, short process, identity marks on tablet surface can be seen through coating
Sugar coating: c. 50% weight gain, formulation: sugar, colorants and others, long process, need to print to identify


Capsule shell composition

Soft (one piece): gelatin, colorants, water, plasticizer
Hard (two piece): gelatin, hypromellose, colorants, water


Capsule identification

Colour- use combinations of approved soluble dyes and insoluble pigments
Printing- use approved pigments and lake form of dyes dispersed in organic solutions of shellac (an edible polymer)
Information- company names and logos, identity code, product name, amount of API etc.


Gelatin capsule filling

What can be filled- powders, granules, pellets, semisolids, liquids (non-aqueous solutions and suspensions)
What cannot be filled- gelatin reactors (formaldehyde), free moisture, large doses, high bulk volume
Hypromellose capsules- do not react with formaldehyde


Capsule filling: powders

Lab scale: manual devices, separate cap from body, powder filled into body with spatula
Industrial scale: dependent- use capsule body to measure dose of powders, fill uniformity requires complete filling
Independent- use separate device to measure powder to produce a plug, capsule body can be part filled


Formulation: influence of API dose

Low dose (<25mg): most of tablet or capsule formulation will be the excipient, challenge content uniformity
High dose (>250mg): most of tablet or capsule will be the API, challenge, compactibility and fluidity
API solubility important for both, governs selection of excipient


Disintegration in vivo

In vivo, signal from radio transmitter in pH meter, inside capsule or attached with string
Capsule filled with sodium bicarbonate


Formulation for release

Capsule disintegration
The rate controlling step is formulation of contents
Active ingredient is the most important component- formulator can modify API by changing particle size
Particle size- change by processing, granulation


Effect of contents on release

Magnesium stearate is hydrophobic, in excess prevents wetting of powder fill and slows down shell rupture


Soft gelatin capsules manufacture and properties

Shell made and sealed in one operation
Sealed at 37c
Capsule wall composition- gelatin, plasticiser (glycerin), moisture content 7-9%, wall c. 400 micrometres thick


Soft capsule formulation

Single liquids, mixtures of miscible liquids, API dissolved or suspended in a liquid vehicle
Difference from hard capsules, shell composition changed according to properties of fill


Types of formulation in soft capsules

Lipophilic liquids/oils
Hydrophilic liquids
Self-emulsifying oils
Micro-emulsion and nano-emulsion systems