Continuous Coating Pan

A continuous coater includes a long, small diameter, cylindrical, rotating pan. Tablets are fed at one end and progress continuously through the machine passing through multiple spray zones to the exit point.

Continuous Coating Advantages

  • Flexible process throughput
  • More uniform distribution of coating material due to:
    • Shallow bed depth
    • More frequent presentation of product to the spray zone
  • Less tablet attrition due to:
    • Shorter process residence time (typically 10 - 20 min.)
    • Reduced depth of the tablet bed

The key difference between a continuous coater and batch coating equipment is in the depth of the tablet bed. The depth of the tablet bed in a continuous coater is shallower. Consequently the tablets are exposed much more frequently to the spray zone, and the time that tablets are isolated from the spray is reduced. The increased number of spray guns and elongated coating chamber contribute to enhanced coating uniformity by improving the consistency of spray distribution across the tablet bed.

Recent advances in continuous coating equipment have virtually eliminated product loss associated with the start-up and shut down of the coating process. These advances also allow coating in a batch mode where tablets are loaded into the drum then either end is blocked off. Tablets are then coated in a batch process. Many of the advantages listed above are still applicable in the batch process.

Recent Developments with Continuous Coaters Include:

Colorcon has conducted trials that demonstrate the suitability of various Colorcon dispersions for use in continuous coating equipment.

  • Software controlled spray gun and process sequencing
  • Coating options, including;
    • Fully continuous coating
    • Batch coating
    • Batch/continuous coating
  • More flexibility for different product volumes
  • Continuous processing with minimal losses

Product Literature