Tablet Pro — Part 1

Improving manufacturing skills within a company is critical to the success and key to continuous quality improvement.

Tablet Pro is exactly what our industry is about today; The methodology, documentation and mindset required to meet the needs of our changing industry.

This means that everyone connected to the manufacturing environment must comprehend the basics of Tablet Making. Managers and Supervisors must now understand the fundamentals of making tablets, because if they do not know the basics they cannot properly support the demands of the new production environment.

Every company has a simple objective…to make a quality product and to strive to maintain and improve that quality. To improve tablet quality we need to completely understand how powder performs, how a tablet press works and be able to understand and control both to make a quality product.

Trouble shooting and root cause analysis require a systematic approach, focusing on the key elements of tablet making. The only way to properly fix a problem is to know “how things work.”

The best manufacturing facilities are the ones that have open avenues to training and also exchange issues between departments. Realize that tablet quality is the report card for all unit operations before the tablet has been compressed.

This booklet is designed to help define the relationship of each department and help to define the basics and essence of making quality tablets.

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Implementation

Providing employee training is a key element in achieving continuous quality improvement. Sending employees off or bringing someone into your facility is only one part of making training effective. To assure your company that training will pay-off you must have a way to implement what is learned.

Be prepared to evaluate what has been learned and apply it in small amounts to your current manufacturing methods. One of the best way to implement training is to establish a list of changes and improvements and evaluate the value and ROI (return on investment) for each change before moving on.

Also, be ready to answer questions. A good trainer will generate enthusiasm and this should generate questions. This is the sign of continuous improvement. Keep in touch with the trainer and get them to help answer the questions. Remember that the objective is to improve quality through knowledge.

Tablet Manufacturing Process

The tablet manufacturing process is the step by step, individual operations required to make powders into a tablet. This is known as individual units of operation; or commonly referred to as Unit Operations. Weighing, Blending and Tabletting are unit operations in the tablet manufacturing process.

When a powder is first developed it may or may not naturally work well on a tablet press. Powders must Flow and Compress in order to make a good tablet. We may need to add many unit operations to make the powders perform.

Each different formula may have a different number of unit operations, which is based completely on the powders ability to Flow and Compress and then eject from the tablet press. We also need the tablet to dissolve and then we need the dissolved particles to disintegrate. These are the factors that determine the number of unit operations required.

Unit Operations

There are three basic ways to process powders for tablet making. Direct Blending, Wet Granulating and Dry Granulating. Direct Blending: Weigh the powders, Blend the Powders and make tablets. Very few tablets can be made by this process.

Wet Granulating: a liquid is added and mixed into the powders, forming bonds between particles…much like gluing particles together. Once a bond is formed the excess liquid is removed through a drying step. This wet granulating technique is the most common way powders are processed for tablet making.

Dry Granulating; is compacting powders and then grinding them back up. Each time a powder is compressed it be comes more densely compacted. A more dense powder will flow better and compress more consistently. This process is used for products too light and fine to compress by Direct Blending and too sensitive for Wet Granulating.

Powder Flow

One of the most important concepts to understand in the tablet making process is powder flow. Powders must flow evenly and consistently. Good powder flow is much like granulated sugar and bad powder flow is much like powdered sugar. They are the same ingredient but yet the flow differently. Granulated sugar flows very evenly and consistently. Powdered sugar flows poorly in comparison.

The basis of achieving tablet weight on a tablet press is through volumetric filling. This implies the need for excellent flow and it also requires that the product have uniform density. Changes in volume or density will result in tablet weight changes.

Powder Characteristics

Different powders have very different characteristics. Some powders are very fine and dry, some are large and brittle, some soft and wet …one thing for certain is they all compress differently from one another. Comparing compression of powders to making a snowball is a good analogy. When snow flakes are large and wet they will compress into a snowball easily. However, when the snow is very fine, light and fluffy the snow ball maker must hold the snow under pressure for an extended period time…relative to the dryness…until a snowball is formed.

Be careful not to over compress the snowball or it will fall back apart. Making a tablet is much like making a snowball. The particle size, shape moisture content lend themselves to the quality of the tablet. Particles must be the same in relation to the other particles or compression of the particles will not be uniform.

Companies that make only one product learn quickly that there are variations batch to batch. These changes are due to the natures of the powders characteristics.

Formula

The ingredients in a formula have a purpose. The main ingredient is known as the Active Ingredient. In pharmaceuticals it is known as the API (Active Pharmaceutical Ingredient). Nutritional Supplements refer to it as ANI (Active Nutritional Ingredient).

The other items in the formula are called Excipients as a category. There are many reasons for putting items other then the API into a formula. We may want to enhance the hardness, increase or decrease disintegration, improve flow, reduce ejection pressure and a host of other reasons.

The formula has an important relationship with the type of tablet press or encapsulator it will be used on. Many companies have purchased high speed presses to find out their own formula will not run as fast as the press can run. This is a common issue, why buy a faster press if the formula will not run as fast as your existing machine. This is not a press issue it is a formulation issue.

Michael D Tousey, Technical Director/CEO