Tablet Coating Flashcards
Sugar coating
Glossy and convex tablets with a 50-100% increase in weight and size
- Polymers, sugar, wax
- Protect against degradation, mask bitter taste, prevent unwanted contact, enhance appearence
Disadvantages of sugar coating
Candy-like taste Excellent media for microbial growth Tends to crack Hygroscopic Weigh increase
Sugar coating Steps
Seal coating Subcoating Smoothing Coloring Polishing Imprinting
Seal coating agents
Shellac and CAP
Subcoating
3-5 layers of sucrose
No visible edges
- Sucrose bases syrups, gelatin, acacia, PVPD
Film coating
Coated with a thin film of polymer
Minimal change in weight, shape and size
Why film coat?
Protection
Mask bitter taste
Alter dissolution profiles
Enhance appearance
Film coating vs sugar coating
Less time Less weight increase Pills or granules No waterproofing More durable, flexible and chip resistant Monogramming is feasible
Aqueous film coating
Film forming polymer
HPMC
Non-aqueous film coating
CAP
Plasticizer
Make polymer flexible and durable by reducing glass transition temperature
PEG Castor oil
Aqueous vs non-aqueous
Aqueous is preferred bc volatile solvents in non
Steps of film formation
Spraying > Wetting > Recrystallization > Coated
Enteric coating
Protect the drug against acidic attack in the stomach
Protect the stoamch from irritants
Facilitate preferential absorption of drug in intestines
Sustain the release
Polymers in enteric coating
CAP
PAP
Diethyl phthalate
