Pharmaceutical capsule filling machines in the market are based on either tamping pin or dosator principles of operation. Their designs feature unique capsule filling processes that guarantee optimal production with low rejection rates.

In most cases, people find it difficult to choose the right technology for their capsule filling requirements. Of course, this is due to inadequate information that is available on the internet.

The bottom line is, the tamping pin and dosator technologies are completely different. Therefore, you need to understand the similarities and difference between these machines.
You can see this from the images below:

A section of the tamping pin capsule filling technology. Image source: University of Maryland (Ph.D. Research by – Augsburger ).

A section of capsule filling machines that uses dosator capsule filling principle. Image source: www.SaintyCo.com

Clearly, you can see the difference between these two sections of the automatic capsule filling machines. You’ll learn more about these sections in the next sections.

The Similarities between Tamping Pin and Dosator Capsule Filling Machines

The key similarities between these two technologies include:

1. In Both Dosator and Tamping Pin, Powder is Changed into Slug

In the two capsule filling technologies, the piston exert an amount of force that compacts the powder together. This results in a small slug that the capsule filling machine later delivers into the capsule.

A tamping pin capsule filling machine. Image source – The Manufacturing Chemist

Transforming the powder into a slug improves yield by ensuring a precise the capsule filling machine delivers a precise dose.

2. The Two Dosing Technologies Guarantee High and Accurate Production

The production speed depends on the type of machine. However, in the automatic capsule filling machines that mainly use these two technologies, the production and accuracy is higher than manual capsule filling machines.

Dosator capsule filling machineTamping pin capsule filling machines
Machine seriesProduction output (capsules per hour)Machine seriesProduction output (capsules per hour)
Z2525,000NJP – 2003,000 – 8,500
Z4040,000NJP – 120036,000 – 72,000
Z180180,000NJP – 350048,000 – 210,000

For instance, the NJP – 1200 automatic capsule filling machine that uses a 5 tamping pin technology has a production output of 72,000 capsules per hour. On the other hand the Z 85– Series capsule filling machine that uses dosator technology has a production output of 85,000 capsules per hour.

In short, machines that use either dosator or tamping pin technologies have a high production out. Moreover, there quite a number of features that guarantee accuracy.

3. You Can Use Dosator or Tamping Pin Capsule Fillers for both Powders & Pellets

Whether you opt for a tamping pin capsule filling machine or a dosator capsule filling machine, you can use the machines for both powder and pellets. However, you may require a little modification in both cases.

Capsule with different contents (powder and pellets)

Normally, you’ll find that the production output for powder will vary slightly compared to that of pellets. Filling pellets tend to be slow.

Of course, other machines are modified to fill tablets, mixture of powder and pellets, liquids, etc. Basically, this capsule filling technologies offer unlimited options in the industry.

4. The Machines can Fill Different Capsule Sizes

Both the tamping pin and dosator capsule filling machines can fill most standard capsule sizes. However, there are some exceptions (I’ll discuss in the next section).

Different sizes of capsules

This may include capsules sizes of: 00, 0, 1, 2, 3, 4 or 5. Basically, both the tamping pin and dosator technologies make the machines versatile and adaptable to any manufacturing technology.

The Differences between Tamping Pin and Dosator Capsule Filling Machines

The main difference between these machines is based on the following aspects:

1. Dosator Machines Are Suitable for Micro-dosing Powder Filling Applications

Capsules in the dry powder inhalers (DPIs) are very small – contain about 200 milligrams or less. Even with this small size, the DPIs must contain the right quantity of powder dose.

For such applications, it’s only the dosator type capsule filling machines that are suitable for such tasks. Normally, the capsule filling machine manufacturers reduce the size of the dosator nozzle to fit the diameter of the capsule.

 

Tamping and Powder Dosing

A section of an automatic capsule filling machine

Still, manufacturers are also exploring other technologies such as the vacuum dosing wheel. Remember, most companies in the pharmaceutical industries need machines that can dispense very small quantities of powders (even as little as 1 milligram).

Clearly, tamping pin capsule filling machine is not suitable for any micro-dosing applications.

2. Tamping Pin Technology is Mainly Suitable for Automatic Capsule Filling Machines

In the recent past, a number of capsule filling machine manufacturers mainly use the tamping pin technology for automatic capsule filling machines. This is because the systems guarantee a high level of accuracy.

Moreover, you can use the tamping pin technology for a wide range of production needs such as filling bad fluid powder, food products, medicines, etc.

Powder Feeding-Tamping System Station

3. The Working Principle of Tamping Pin Filling Machine vs. Dosator Type Capsule Filling Machine

This forms one of the key aspects that differentiates these two types of capsule filling machines. Let’s review these two technologies here:

  • Tamping pin capsule filling machines

They have several pins – in most cases 5 pins. It has a dosing disc with several holes on its surfaces.

Tamping pin dosing system of a capsule filler machine

Normally, these holes remain closed with the tamping plate. The process is such that, as the powder flows into the holes (from right to left in the image above), the tamping pin compresses it thereby, compacting its particles together.

As the dosing plate rotates, the holes move to the next tamping pin, powder flows in as it gets compressed. Basically, the powder undergoes successive compression to a controlled depth.

This results in a powder slug that is finally ejected into the capsule shell.

  • Dosator capsule filling machines

These machines have a dosator and a pin. The design is such that the dosator has a small hole/cavity at its tip.

A section of dosator system of a capsule filling machine

Therefore, inserting the dosator into the powder bed ensures that that loosely packed powder fills this cavity. With the powder in the cavity, a small pin in the dosator system exerts a small amount of force that compacts the powder into the dosator cavity.

This forms a slug, which is later ejected into the capsule.

Clearly, you can see that dosator process is quite simple since it does require a successive compression of powder.

Even though the working principle may vary, the machines will still serve the same purpose – filling capsules.

I know there are other aspects that you need to consider such as:

  • Cost of the equipment
  • Complexity in design
  • Portability
  • Reliability
  • Material type
  • Safety measures
  • Automation mechanism

All these do vary depending on the manufacturer of the machine. So, you need to review all series of capsule filling machines your dealer offers.

Conclusion

The tamping pin capsule filling machines and dosator type capsule filling machines may vary when it comes to design, application type, production output, etc. This is why I recommend that you consult widely to ensure you purchase the right equipment.

You need to review the production output of every equipment and the recommended fill materials. Also, don’t forget to review the product catalogue/manual to get a comprehensive information about a particular machine.