Equipped with decades of experience in tablet manufacturing, the team at Fette Compacting has the knowledge and skills to assist customers in all of their tableting operations. From research and development to production, we supply customers with the necessary products and services throughout the entire tableting process to ensure they achieve the highest product quality attainable.

For industry professionals looking for a fuller understanding of tableting, we’ve outlined a cursory introduction: what it is, the different stages of the process, the basic components of a tablet press, and the types of tablet presses available.

What is tableting?

Tableting is an umbrella term for any of the procedures used to compress a powder formulation into a solid tablet form. In recent years direct compression has become extremely popular in the tableting industry. This is due in part to its low cost and simplicity. It combines the blending and compressing of these ”dry” powders, resulting in much higher processing efficiency. Direct compression, or (DC) as it is known in the industry, is the mixing of raw materials into a uniform blend, which are then compressed into a final tablet.

Overview of the Tableting Process

The first phase of any tableting operation is identifying an appropriate formulation for a given tablet. In this early phase, the customer and raw material supplier will work together to determine the composition of the tablet. No matter the industry, the decision on exact ratios for ingredients is always important, but this importance is greatly increased when making pharmaceutical-grade tablets where active pharmaceutical ingredients (APIs) are present. Excipients, or “fillers” are often also present and include, but are not limited to, binders, diluents, lubricates, disintegrates, etc. The resulting percentage of API found in the final tablet form is often referred to as the “drug load.”

Once the powder material is ready, it may undergo granulation to achieve the proper particle size distribution for optimal tablet formation. The two main approaches to granulation are:

• Wet granulation. The most common of the two primary granulation techniques—wet granulation—involves the addition of a liquid binder to the powder mixture. The binder is controlled via drying in a fluid bed dryer.
• Dry granulation. Dry granulation aims to achieve the same granular texture as wet granulation without the addition of any fluids. This texture can be achieved through slugging or roller compaction. In slugging, a static press is used to turn the powder into formed slugs, which are then milled (sized) into a more granular, uniform This method allows for the formation of stronger bonds between the powder particles. Roller compaction employs a set of rotating rollers to compress smaller particles into a ribbon or sheet, rather than slugs. Generally this method allows for faster processing rates and greater control over compaction pressures.

Once the granulation process is complete, it is now ready to be fed into a tablet press. Granulation is fed into the hopper via hand scooping, overhead gravity feed, or vacuum conveying. Immediately following the hopper is a feeding system (generally an induced feeder, with rotating paddles inside), which helps meter the granulation into the die cavities. The shape of the cavities define the final form of the tablet, and the granulation that has been fed into them is then positioned between the upper and lower punches. The punches are then brought closer together as they follow a series of cams with differing angles, and pass between upper and lower compression rolls. Pressure is then applied to the granulation forming a solid tablet.

Basic Components of a Tablet Press

Although there are many variations on the tablet press, most use some combination of the same components. These components include:

• Hopper. The hopper holds the powder material before it undergoes the tableting process.
• Feeding mechanism. The feeding mechanism attaches the hopper to the cavity, allowing for the movement of powder material into the cavity.
• Die. The cavity of the die determines the shape of the tablets produced.
• Punches. The upper and lower punches apply vertical force to the die, causing the powder contained within to compress and conform to the shape of the cavity.
• Cam track. The cam track regulates the movement of the punches.

Types of Tablet Presses

The basic tablet press components can be combined in different ways to accommodate different tableting volumes. For example:

• Single station tablet presses—also referred to as single punch or eccentric presses—feature only one tooling station with a die, a static lower punch, and a dynamic upper punch. They can be manual or motor operated.
• Multiple station tablet presses—also known as rotary tablet presses—employ a rotating turret (with upper and lower punch rings/punches and a die table), cams, and cam tracks. The press is configured such that the punches corresponding to the dies are positioned above in the upper and lower punch rings and below the die table. When the turret rotates, the variable raising and lowering of the punches via cams forces the punches to compress the powder into tablet form and the lower punch subsequently ejects the tablet from the die. The cam tracks ensure that filling, compression, and ejection operations all operate in a controlled and predictable fashion.

Partner with Fette Compacting for Your Tableting Needs

For decades, Fette Compacting has supplied customers with tableting solutions. Our years in the tablet manufacturing field have culminated in the development of industry-leading technology—both in regard to the design of the press system and support components—that offer faster processing speeds, shorter downtime requirements, and better product quality for customers.

In addition to providing quality tableting presses, we offer the following services:

• Research and development support
• Machine testing
• Employee training
• Machine refurbishing and rebuilding
• Preventative maintenance

For additional information about tableting, download our eBook, A Guide to Optimizing and Enhancing Your Tablet Press Performance or contact our experts today.