In the April edition of Tablets and Capsules, Mr. Nick Slater, Freund-Vector’s Senior Process Development Scientist, discusses the qualitative relationships between key parameters when using a perforated pan film coater.  Tablet coating isn’t an overly complex process, but proper coating setup and operating parameters ensure that your tablets are coated evenly and adequately without defects.

What are the key parameters for using a perforated pan film coater?

1. Batch size: Most fundamental coating parameter. Batch size affects pan speed, spray gun setup, spray rate, bed temperature and process airflow.
2. Coating-pan speed: The goal is to achieve a uniform, cascading motion as the tablets travel through the spray zone.
3. Spray-gun setup: Simplest way to test a spray gun’s atomization and spray pattern is to remove the spray bar and spray some solution onto a piece of paper while matching the distance between the spray nozzle and the tablet bed in your coater.
4. Spray rate and bed temperature: Spray rates can range anywhere from 50 to 220 grams per minute for aqueous coatings and bed temperatures can range from 22° to 60°C.
5. Process airflow and dew point: The process airflow carries heat, which encourages evaporation and dries the coated tablets. The process air dew point maintains optimal spray rates in your coating system.

Starting with the development of the world’s first successful automated film coating machine in 1964, the Freund group has established itself as a global leader in tablet coating systems and technologies.  Since the worldwide launch of the Freund-Vector HI-COATER® in 1974, our perforated coating pans have featured slotted perforations.  When compared to round-hole perforations used by other suppliers, these slotted perforations provide reduced tablet attrition and even allow the coating of mini-tablets as small as 1.5mm.

To learn more about tablet coating, you can attend one of Freund-Vector’s Granulation and Coating Seminars.  These seminars are offered in Villasanta (Milan Area) and Marion, Iowa. These seminars give industry professionals an overall understanding of the processes and operation of solid dosage equipment.  Attendees can see and understand what happens when changes are made to process parameters and the results. Without a doubt, the demonstration gives an understanding of what “To Do” and what “NOT To Do” when it comes to granulation and coating technologies!