Tablet coating might seem like a simple process from the outside, but to consistently achieve equal distribution and uniform coating across the tablet surfaces, you need superior coating equipment.
In the pharmaceutical industry, the tablet coating process is used to cover the surface of tablets with a thin coating of a film or coating solution. This film has multiple purposes depending on the medication, dosage, and treatment plan. There are many reasons why you might apply a coating composition to your tablets.
- Masking the taste or smell of a drug
- Protecting the drug’s ingredients from contamination
- Implementing a delayed release for the drug
- Preventing the drug from being dissolved in stomach acids
- Improving the overall appearance of a drug
You might also add other drugs or materials to the coating to prevent any chemical incompatibilities from reducing the effects of the medication.
Thomas Processing has been in the pharmaceutical machinery business for over 60 years. During that time, we’ve seen technology and processes change time and time again. Throughout these changes and transformations, we have remained committed to achieving the highest quality in tablet production. We also believe in educating our customers so they can make informed decisions about the equipment they use and the machinery they purchase from us.
Many types of tablet coating machines are available in the industry today. Below, we describe three primary types and some of their details.
Standard Coating Pan
A primary component of this process is a circular metal pan that is slightly tilted on a benchtop stand. The pan is typically rotated by an electric motor. During the tablet coating process, a batch of tablets is loaded into the metal pan, and it is set to rotate. This motion causes the tablets to tumble around the interior of the pan.
The coating materials for the tablets are applied by an atomized spray into the pan. The purpose of the spray is to apply and distribute the coating film more evenly. From this point, there are multiple possible options for drying the tablet bed. They all primarily use different methods of drying or heated air through a diffuser or system of tubes.
Fluidized Bed or Air Suspension System
With a fluidized bed coater, the coating involves a vertical cylinder. Fluidization of the tablets is performed by a column of air flow from the bottom forcing the tablets upwards in the cylinder. The tablets flow to the top of the column before falling to the bottom and re-entering the stream of air to go back up.
The sprayed coating is forced through nozzles at the bottom as the tablets travel around the cylinder. Many tablets are frail and prone to chipping or abrasion. This makes the air suspension system a selective solution for tablet coating as the tablets impact each other and the tablet chamber many times during the coating process.
Perforated Pan or Drum
This method is offered by the equipment and coaters we provide at Thomas Processing. The process consists of a fully-perforated drum rotating on a horizontal axis. The whole system is enclosed. The coating solution is applied by a spray bar nozzle or gun positioned within the center of the drum. At Thomas, we offer options like external gun positioning and independent control of pattern and atomizing air.
With our ACCELA COTA system, the drying air flows directly to the drum and passes through the tablet bed before being released through the perforations in the drum. Perforated drums are among the most popular selections in the modern pharmaceutical industry. Many of the tablet coaters from Thomas also come with the convenience of exchangeable drums to reduce the chance of cross contamination and provide faster batch-to-batch changeover times.
There are many factors to consider in the manufacturing process. Does your drug need a delayed-release coating? Should you use enteric coating? With all of these elements to manage, it can be helpful to eliminate some variables and simplify the process as much as possible. When you purchase pharmaceutical machinery from Thomas Processing, our equipment comes with our ongoing support.
Before and after our coaters are delivered to your facility, we perform a series of qualification tests to ensure it will offer the performance we promised. These services give you peace of mind in knowing your new equipment will perform as intended. Our people are also available to deliver onsite, hands-on training for your employees. You can even depend on Thomas for spare parts/kits and equipment maintenance throughout the lifecycle of your equipment. Thomas Processing is committed to driving innovation in tablet coating machinery and providing superior customer support for our clients.
To learn more about tablet coating machinery and the services we offer, contact Thomas Processing today.