Coating Defects*** Flashcards
*Local DETACHMENT of film from the substrate forming blister
*Cause: too high temp
Blistering
*Appearance of VOLCANIC-like craters exposing the tablet surface
*Cause: inefficient drying, high rate of coating solution application
*Remedy: optimum drying conditions, increase viscosity of the coating solution
Cratering
*Isolated areas of film are PULLED AWAY from the surface when the tablet STICKS together and then PART
*small amount of material from a tablet is sticking to and being removed off from the tablet surface by a punch face
*Occurs when the granules STICK to the DESIGN embedded in the PUNCH TIP such as in the lettering or logo
*Causes: similar to cratering
*Sticking: Problem in die
Picking
Keyword: Punch
*PITS in the surface of the TABLET CORE without any visible disruption of the film coating
* Cause: inappropriate drying temperature
Pitting
*Coating becomes DULL immediately or prolong storage at high temp
*Cause: Plasticizer problem (high conc or low MW)
Blooming
*Whitish/White specks or haziness in the film
*Reason: precipitate polymer exacerbated using high temp
Blushing
- Filling of INTAGLIATIONS (engrave) (logo, monogram) → indistinct and illegible
- Same end effect as bridging
- Cause: accumulation of bubbles or foam within the intagliations rather than dispersion over the whole tablet
- Remedy: add alcohol to the polymer solution to improve dispersion
Infilling
*Coating solution fills in the lettering or logo on the tablet.
*Cause: poor design of tablet embosses, high viscosity/solid particles
Bridging
*Tablet surface becomes ROUGH and NON-SHINY (non-glossy)
* Causes: High solution viscosity resulting in inadequate spreading of the coating solution; rapid drying
Orange-peel
*Films CRACKS across the CROWN of the tablet, or SPLITS around the EDGE of the tablet
* Reason: internal stress in the film
Cracking/Splitting
Variation in colors in the film
Color variation
*Partial or complete separation of the TOP or BOTTOM of tablet
*FRACTURE at the TOP of the tablet and separating itself from the tablet body.
Capping
*Separation of tablets in LAyers
*Occur as a SPLIT in the tablet anywhere except the top; it often happens due to over compression of the tablet
LAmination
BREAKING of tablet edges
Chipping
UNEQUAL distribution of COLOR in the tablet
Mottling
Due to free ROTATION of the PUNCHES during ejection
Double impression
Upper and lower central SURFACE CRACK
Cracking
*Tablet material ADHERING to the die wall
*Occurs when the granules of a formulation become STUCK to the face of the PRESS PUNCH
Sticking
Process Related
'’prAcess’’
cApping
lAmination
crAcking
Excipient Related
'’excIpient’’ - unang I
chIpping
stIcking
pIcking
bInding
Machine Related
'’MacDo’’
DOuble impression
MOre than 1 factor
MOttling
Partial spray drying or OVERWETTING causing soft coating to rub
Rough coating
Coating cracks due to thermal expansion of tablet cores caused by OVER-DRYING
1nit
Film-cracking (Type I)
