Tablet Discoloration

Discoloration is seen either through or on the coating, caused by interactions of ingredients in the core or by heat from the process causing ingredients in the core to migrate through the coating. Problem is commonly seen with nutraceutical products.

Coating Formulation Sprayable coating solids are too low, allowing moisture to penetrate into the core during application of the coating. Learn more.
  • Consult with Ashland to select an Aquarius™ film coating system capable of being sprayed at higher solids.
Coating system requires processing temperatures that promote migration of ingredients from core.
  • Consult with Ashland to select an Aquarius film coating system capable of being applied at lower processing temperatures.
Product is not receiving enough protection from moisture during storage.
  • Consult with Ashland to select a suitable Aquarius film coating formulation capable of environmental moisture protection.
Coating Process Discoloration caused primarily by moisture from the coating process promoting interaction between ingredients in the core.
  • Decrease spray rate and/or increase processing temperatures.
  • Increase pan speed to reduce dwell time in the spray zone.
  • Ensure that spray gun setup has been optimized so that there is no mis-spraying, that all spray guns are spraying at the same rate, and each is providing the same area of coverage over the tablet bed surface.
  • Increase solids content of coating liquid.
Discoloration is caused by melting and migration of ingredients in the core.
  • Increase spray rate and/or reduce processing temperatures.