It’s never been enough to deliver tablet coating equipment that simply works well. Thomas Processing has always taken it a step further with process optimization and the tools you need to achieve the desired results in your tablet coating process. The TAAC computer model is another example of how we help your users accomplish those results.
The pharmaceutical tablet coating process can be a daunting task if you don’t have the right tools and techniques. End users and customers depend on the quality of your coating materials and the reliability of your process. You need to have comprehensive quality control across whole batches of tablets.
Those batches could range from bulk productions to small clinical trials, but the challenge remains. It can feel like the ultimate challenge of quality versus quantity, but it doesn’t have to be that way. Thomas Processing has the expertise and mathematical models to make this hill easier to climb.
Thomas Processing has a strong history of innovation and never saying no to a new challenge. To discover everything we have to offer beyond our line of industry-leading tablet coaters, take a look at our services page today.
Today, we’re going to focus on the TAAC computer program. TAAC stands for Thermodynamic Analysis of Aqueous Coating. It relies on the first law of thermodynamics to analyze the film coating process going on inside your tablet coater.
The computer model uses the math behind thermodynamic heat and mass transfer to accurately display the environmental conditions inside a coating pan during a steady-state film coating process. Let’s break down what all of this means and how it helps your coating operations.
The Automatic Film Coating Machine Must Be a Monitored Environment
The process of applying film coating to tablets might seem straightforward from the outside, but in reality, it is a detailed program that needs to be monitored and controlled to achieve the desired results. We can lay out the basic, necessary steps of the process itself from a high level:
- Tablets are placed in a coating drum, which then rotates and mixes the tablets.
- Ambient heated air is forced through the perforations in the drum to warm the tablets.
- This ambient air is vented from the drum.
- A solution of coating materials is sprayed in fine droplets throughout the bed of tablets.
- The distance between the spray gun and the tablets is measured and adjusted to reach the desired uniform coating across the batch of tablets.
- Droplets of the solution hit the tablets and spread into a film across the tablet surface.
- Conditioned air evaporates the water from the solution, leaving behind the tablet film coating.
- The desired thickness of the coating is increased or reached as the tablets pass under the spray by the rotation of the drum.
Behind all of these steps is the complex math of the coating composition, the environmental conditions of the interior of the tablet coater, and the desired thickness of the coating that ensures the sustained release of the drug for the end user. When it all works together, it can seem simple, but that’s only because today’s processes are standing on the shoulders of years of hard work that came before them.
Aqueous Film Coating Has Been Around Many Years
During the late ’80s, aqueous coating was rapidly becoming the preferred method for applying a film coating to pharmaceutical tablets. The technology and methods at the time grew to the point where proper adhesion, toughness, and controlled release could all be achieved without depending on the organic solvent-coating technique. The older organic solvent coating technique was an environmental concern due to its volatile nature.
Cost, safety concerns, and increasingly stringent federal regulations helped push aqueous film coating to the forefront of pharmaceutical tablet coating.
When organic solvents were involved, there had to be strict safety protocols and even alteration to the equipment. There was also more responsibility on the company to properly dispose of the volatile waste solvent after the tablet coating. Aqueous film coating is non-toxic and excess evaporation could be vented into the atmosphere without concern for the environment. The evaporation process with aqueous took longer than solvents, but eliminating so many safety concerns proved to be worth the time.
The new challenge with aqueous film coating was how to account for all the process variables. A process variable is how one element of the tablet coating process affects another. For example, how a change in the spray rate could affect the temperature of the exhaust air.
There needed to be an analytical technique for accurately describing how the variables in the tablet coating process were altered by the use of aqueous-based film coating. With this information, users could then make adjustments and ensure quality control across their lines of production. From this need, the TAAC computer model was born.
The first law of thermodynamics states that energy cannot be created or destroyed; energy can only be transferred or changed from one form to another. There are multiple forms of energy at play in the tablet coating environment, and TAAC helps the operator accurately track their interactions.
The tablet coating process is closed off from the outside environment. As we stated above, the aqueous film coating process uses conditioned air to evaporate water from a coating solution that is sprayed onto the bed of tablets.
Thanks to the first law of thermodynamics, we know that if the temperature, air flow rate, and humidity of the air going in and the delivery of the solution are all held constant, then the temperature and humidity of the air coming out will also remain constant. This means what goes into the pan during the coating process can be directly compared to what comes out.
There are two main purposes behind TAAC.
- It enables a user to investigate the relationships between process variables.
- It also allows the user to measure the drying rate of the aqueous film coating.
It is this second purpose that is often given the most attention. The analysis from TAAC provides the user with the precise film drying rate during a given set of conditions. Once the user has that, they can use it to reproduce the desired quality in a completely different set of conditions. The same drying rate results in the same film coating quality. And it’s all about that film coating quality.
TAAC is used across the world of tablet coating. It is part of film coating processes in thousands of companies in hundreds of countries. It’s reputation and continued use throughout the industry speaks for its effectiveness.
TAAC uses heat and mass transfer equations to identify and characterize the tablet coating environment for the user. The heat is transferred as the heated air going in hits the tablet bed and the mass transfer occurs as the water is evaporated. The number generated by these equations is the Environmental Equivalency Factor or EFF. It is the ratio of heat transfer to mass transfer. The EFF fluctuates based on moisture; a higher EFF is dryer, and a lower is EFF is wetter.
All of this boils down to the fact that if you have a constant EFF number, then you have a constant coating quality. You can alter certain parameters of your process, but as long as the EFF is maintained, then the quality of your tablet coating will be reliable and sustainable. This is how the TAAC computer model helps your operations achieve comprehensive quality control across multiple batches.
At Thomas Processing, we believe every process presents the opportunity for optimization. Ask us today how our experts use process optimization to examine your operations and find opportunities for improvement.
We’ve laid out why the TAAC is useful, and some of the principles behind how it works, but how does all of that play into your day-to-day work? What makes TAAC valuable to your organization? The TAAC computer model can be an essential part of applications including:
Developing new coating recipes
Coating recipes are a vital part of the production process. Our tablet coaters can store hundreds of recipes. TAAC allows you to develop recipes based on your past performance.
Optimizing an existing process
We know all about process optimization. You’ve likely got products that you’ll be producing again and again for years to come. Be confident that your process is performing at its best.
Transferring a process to a new site or differing equipment
Your operation could be moving to a new location, or perhaps you purchased new equipment. You should be equipped to make the transition without a dip in quality.
A cost/benefit analysis of air handling equipment
We all need to weigh the costs of future spending against the benefits of the purchase. This gives you mathematical certainty of the EFF analysis.
Scaling up or down from one size of production to another
You could be moving something out of clinical trials and into large-scale production. You don’t want to risk a drop in quality during this transition.
Investigating the effect of seasonal air humidity
Through winter, spring, summer, and fall, the humidity in the air will change. Your operations run year-round, and it’s vital to be prepared for these changes as they come every year.
The ability to accurately predict the behavior of the tablet coating process under a variety of different circumstances is a valuable tool. It is extremely useful to anyone involved in pharmaceutical production or research and development.
With TAAC, much of the work involved in the above applications can be performed on paper, and not in actual practice. This one change saves substantial time and materials for your business.
The challenge of quality versus quantity is not such a tall hill to climb when you’ve got the right tools. The TAAC software has been around for a long time, but it still proves useful today to the modern pharmaceutical tablet coater. We have a long tradition of innovation, and your organization can be part of it.
For over 60 years, Thomas Processing has been pushing the pharmaceutical tablet coating industry forward with new innovations and a passion for stellar customer service. We’ve developed tablet coating systems that deliver longevity and an ample return on your investment with our Flex line of pharmaceutical machinery. We provide user interfaces and control systems that are simple to run and intuitive to your needs. Our team offers hands-on, onsite training for your users on the equipment they’ll be using and in your facility.
Thomas is there to support your operations in the future with services like spare parts and kits, equipment maintenance, and process optimization. We want to be more than your equipment supplier; we want to be your competitive edge in the industry. Another essential part of the tablet coating process includes wash-in-place (WIP) and clean-in-place (CIP) systems.
WIP and CIP refer to the process of cleaning equipment and machinery without requiring disassembly to save time on production and changeover. To reduce your organization’s expenses and still deliver quality, we offer certified pre-owned equipment professionally refurbished by our team and backed by our limited warranty.
To learn more about our systems and services, reach out to Thomas Processing today.