Tablet Manufacturing Machines Used in the Pharmaceutical Industry

Nowadays, compressed tablets are one of the most popular dosage forms. The size of tablets which is to be taken down (taken into the stomach) varies from millimeters to centimeters. While preparing the tablet, a type of symbol, number, or letter is used to identify them. Different shapes of tablets like capsule shape, oval and round, can be prepared but the need of the patients and the tablet machines are very important factors for tablet making.  In this article, we will talk about different types of tablet manufacturing machines. This article will help you a lot by providing information about tablet manufacturing machines and their operations.

Tablet Manufacturing Machine

What is the Use of Tablet Compression?

The shape and diameter of the tablet dosage form are determined by the tooling used to produce tablets, which means a die and upper and lower punches. This is also known as the station of tooling.

During the compression of the tablet, the tablet compression tooling is in close contact with the tablet so that a smooth production of the tablet can be obtained with the help of tooling.

The selection of tooling is totally depending upon the type of product prepared. The proper care and maintenance of tooling help in getting standard-quality tablets.

What are the Different Parts of a Tablet Machine?

Punch:

The end part of the punch is the punch head which is moved in the cam track. The flat surface of the punch head that is at the time of compression, contact with the compression roller is known as head flat.

The angle of the punch head which is in contact first with the compression roller is known as an outside head angle, and the angle which contacts the upper punch, and lower punch is known as the inside head angle.

The part of the punch between the head and barrel is called Neck.

The vertical distance between the end of the punch tip and tip to stem radius is called Tip length.

The rounded face of the tablet is prepared or formed by the curved part of the punch tip face, known as the Punch cup.

The distance between the punch tip and the edge of the punch cup is known as Land.

If there are different shapes (except round shape) of the tablet required then the key is used to align the punch in a unidirectional vertical way.

Die:

The distance between the two vertical edges of the die is known as Die outer diameter.

The distance between the upper and lower end of the die is known as Die height.

The tablet is formed in a hollow cylindrical part of the die which is called a Die bore.

The Chamfer guides the punch into the die bore, which is the die bore's end part, and the Chamfer's diameter is slightly higher.

The die-locking screw is used to lock the die groove to keep the die in a properly aligned position in the die pocket.

Single-Punch Tablet Machine (Single-Punch Presses):

This is the simplest machine. Different models of the single-punch machine are available.

The compression is performed on a single punch machine in such a way that;

The feed shoe is placed over the die cavity and filled with granulation.

The feed shoe withdraws and collects all the excess granulation away from the die cavity.

Then the upper punch gets down to compress the granulation within the die cavity.

The upper punch (retract) takes back and the lower punch comes up to eject the tablet.

Then the feed shoe returns to fill the die cavity and it pushes (press forward) the compressed tablet from the die platform.

The volume of the die cavity determines the weight of the tablet. It is totally depending upon the lower punch which is adjustable to increase or decrease the granule's volume, and so, increasing or decreasing the weight of the tablets.

After completing the process, remove the dust from the vacuum cleaner, release the punch pressure, remove the feed hopper and shoe, and remove the upper, and lower punch, and the die. Clean all the surfaces of the tablet machine and dry with a clean cloth also apply the grease or oil before storage.

The output of a Single-punch tablet machine: Approximately 200 tablets per minute.

What is a Rotary Tablet Machine?

Rotary Tablet Machines (Rotary Tablet Presses):

Manufacturing tablets through this method is preferred because it promotes a uniform fill of the die cavity and accurate weight of the tablet.

Compression occurs when the upper and the lower punch moves between the pair of rollers.

Due to this motion, a slow squeezing effect (over the material) is created in the die cavity from the top to bottom, and it gives a chance for the entrapped air to get out of the way. Then the lower punch moves up and the tablet gets ejected.

While the machine is in operation, without the use of any tools, the adjustment of tablet hardness and weight is constructed. The internal flow of the granulation within the feed hopper is one of the factors that helps in tablet weight variation and hardness.

It compresses the number of granules which is present in the die cavity in between two rollers by using an upper and lower punch. Changing the distance between the rollers, the force can be adjusted which is used to compress the tablets. After setting the distance between the rollers, the compression force will remain the same.

Many factors like granule size, variation in punch length, and size distribution can affect the number of granules present in the die cavity.

How does a Tablet Press Machine Work?

Operation of Rotary Tablet Press:

Before starting the operation, the pressure wheel pressure should be released. The die-to-seat and die holes should be thoroughly cleaned.

Take a look at the dies and loosely insert them into the die holes, then put each die into the place, the upper punch holes. Tighten each die Very securely with the locks crew.

Now, by removing the punch head, insert the lower punch in its place and also insert the upper punch by dropping it into the head.

Before insertion into the machine, both the upper and lower punch should be coated with mineral oil.

Adjust the ejection Cam in such a way that the lower punch is flush with the die table at the ejection point.

Then, adjust the machine for tablet weight and harness.

The feed frame and feed hopper should be attached to the machine.

Now, add the small number of granules through the hopper and turn the machine on.

By rotating the pressure wheel increase the pressure until a tablet is formed.

Now, check the weight of the tablet and adjust through the fill to provide the desired tablet weight. Many adjustments are required before obtaining the desired weight.

If the fill is decreased, the pressure should also be decreased to get the same hardness of the tablet. Reciprocally, if the fill increased, the pressure should also be increased to obtain the same hardness.

Check tablet weight and hardness immediately after the operation starts and make necessary adjustments if required. Check these regularly after 15 to 30 minutes intervals.

After completing the batch, remove the hopper and feed frame from the machine also remove the dust through the vacuum, and remove all pressure from the wheel.

Then, remove the upper punch than the lower punch, and finally remove the dies. Wash each punch and die in alcohol, and remove any sticking materials with the help of a soft brush. Dry them with a clean cloth and cover them with a thin coating of oil or grease before storage.

The output of the Rotary tablet press: More than 5000 to 10000 tablets per minute.

Causes of Tooling Problems:

In tablet compression tooling some problems may arise due to the compression of the tablet. These problems can be either mechanical or formulation problems.

The formulation problems like humidity, moisture content, and material roughness.

Mechanical problems like uneven wear and tear and corrosion of punch faces, higher compression forces, improper polishing, etc. This may cause the failure of the tablets to meet the quality standards.

I hope you like my article on Tablet Manufacturing Machines Used in the Pharmaceutical Industry. I give information about different types of tablet manufacturing machines and their operations. If you have any questions or queries related to the article then feel free to ask in the comment section.

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