Filling capsules might seem straightforward, but anyone who’s worked in the pharmaceutical or nutraceutical space knows it’s anything but simple. From inconsistent fill weights to handling sticky or sensitive formulations, small issues can quickly turn into major production slowdowns. Whether you’re just getting started or looking to scale up, understanding these challenges, and knowing how to navigate them can make a huge difference in your output, product quality, and bottom line.
Below are five common hurdles manufacturers face during capsule filling, along with practical solutions that can help streamline your process and keep production running smoothly.
- Inconsistent Fill Weights
Maintaining uniform fill weights is one of the most important and most frustrating — parts of capsule production. Whether you’re working with powders, oils, or gels, inconsistent fills can lead to rejected batches, inaccurate dosing, and even compliance issues in regulated industries.
What causes it: Variability often stems from poor flow properties in the product, improperly calibrated equipment, or environmental factors like humidity. In manual and semi-automatic setups, human error can also play a role.
How to fix it: Improving product uniformity is step one, using flow agents or controlling moisture content can go a long way. It’s also essential to regularly calibrate and clean your equipment to avoid drift. If you’re working with liquid fills, automation offers the best control. Systems like ATG Pharma’s RoboCAP use precision volumetric nozzles to achieve consistent fill weights, even with variable product viscosities.
- Dealing with Sticky, Viscous, or Temperature-Sensitive Products
Not every product is free-flowing or easy to work with. Many formulations, especially those in the wellness or cannabinoid spaces are thick, sticky, or sensitive to heat and shear, making them difficult to dose consistently.
What causes it: Products with high viscosity or those that separate over time present dosing challenges, particularly when using basic or manual equipment. Some may also react poorly to heat or exposure to air.
How to fix it: The key here is temperature control and mixing. Heated tanks and nozzles can help maintain a stable fill temperature, improving flow and reducing clogs. Continuous mixing prevents separation and ensures consistency from the first capsule to the last. Even in smaller-scale setups, adding jacketed tanks or inline heaters can dramatically improve results. For automated systems, look for filling machines with integrated temperature and mixing control to manage a wider range of formulations without slowing down production.
- Capsule Misalignment and Product Spillage
Misaligned capsules are more than a minor inconvenience, they lead to wasted product, downtime, and potential contamination. And when you’re working with high-value ingredients, those losses add up fast.
What causes it: Manual filling setups often lack alignment aids, making it easy for capsules to shift or spill during filling. In some cases, static charge can also cause lightweight capsule tops to move unexpectedly.
How to fix it: Trays and jigs that secure both the body and cap during the filling process can help reduce movement. Anti-static materials or ionizing air bars are also useful for keeping everything in place. In high-volume environments, equipment that automates capsule separation and orientation can minimize human error and increase output. ATG’s capsule accessories, like the Pro Filler tray, provide manual stability, but even small process tweaks can reduce misalignment issues.
- Air Bubbles and Product Waste
When filling capsules with liquids or gels, air bubbles are more than just a visual issue, they lead to inaccurate dosing and wasted material. Worse still, they can compromise the product’s integrity or shelf life.
What causes it: Air can get introduced through pumping systems, especially when the product isn’t degassed, or the pressure isn’t properly controlled. Inconsistent flow from gravity-fed systems can also be a culprit.
How to fix it: Degassing the product before filling is the first step. Using closed, pressurized systems helps maintain even flow and reduce turbulence that can trap air. If you’re noticing a pattern of bubbles, check your tubing and nozzles for air leaks or restrictions. Many automated systems, including the RoboCAP, use bottom-out pressure vessels that help ensure consistent flow while minimizing product loss and air entrapment.
- Scaling Production Without Losing Efficiency
When it’s time to increase output, many manufacturers hit a wall. Manual or semi-manual systems can only take you so far before bottlenecks start to impact your delivery timelines and margins.
What causes it: Scaling challenges usually stem from a mismatch between equipment capabilities and production demands. Adding more labour isn’t always the answer, it often leads to diminishing returns and more variability.
How to fix it: The key to scaling is finding equipment that grows with you. Start by optimizing your current process — identify slow points, clean more frequently, and track batch performance. Then, look at modular or upgradeable systems that let you increase capacity without replacing your entire setup. ATG Pharma’s RoboCAP RL-300, for example, offers scalable configurations that evolve with your production needs, making it easier to scale while maintaining accuracy and minimizing downtime.
Capsule filling doesn’t have to be a constant source of frustration. With a clear understanding of where problems arise and how to fix them, you can improve your workflow, reduce waste, and produce a more consistent, higher-quality product.
At ATG Pharma, we’ve seen how thoughtful process design, and the right equipment can transform production. Whether you’re filling 500 capsules an hour or scaling up to thousands, success starts with knowing your product, fine-tuning your setup, and investing in solutions that meet your needs today, and tomorrow.
Want to learn more about capsule filling solutions and how to level up your process? Explore ATG Pharma’s capsule filling equipment here.