Logo bridging
The film lifts out of an embossed logo or break line and spans across it, so the debossing goes shallow or disappears.
Tablet coating defects and what causes them
What each defect looks like and what usually sits behind it. The correction depends on your core, your equipment and your batch, so it is settled at trial rather than prescribed here.
Picking and sticking
Tablets adhere to each other or to the pan, and fragments of film or core pull away, leaving pitted faces.
Orange peel and roughness
A dimpled, matt surface rather than a smooth gloss, most visible under raking light.
Colour variation
Shade differs tablet to tablet within a batch, or between batches that were meant to match.
Loss of gastro resistance
An enteric batch that looks correct fails the acid stage, releasing before it should.
Moisture driven instability
Coated tablets pass release but drift on stability. Colour changes, assay falls, or degradation products rise.
Dissolution failure after coating
An uncoated core that met specification falls outside it once coated, or disintegration time lengthens.
What causes dissolution failure after coating, and what to change
Running into one of these on a batch? Send us the core and the symptom and we will work back from there.
Work the numbers
Most of these come back to a figure.
Bridging and gastro resistance failures are usually a build-up problem. Picking, orange peel and spray marks are usually a spray rate problem. Edge wear is usually a pan speed problem.
What a good film looks like
Metallic gold film coat
Metallic blue DB3012
Aqueous colour film coat
Extra white film coat