Tablet manufacturing is a complex process completed in various steps in pharmaceutical industries.The process of tablet manufacturing starts from the powders and ends to the coated or uncoated tablets.
The journey of tablet manufacturing from powders till coated tablets is divided into following three main parts.
- Granulation
- Compression
- Coating
Granulation
The first step involved in the manufacturing of tablets is the granulation where fine powders are converted into the granules and the process of granulation is further divided into various steps.
There are two main types of granulation one is known as wet granulation and other one is known as dry granulation.
Which method of granulation is suitable for tablet manufacturing depends upon the sensitivity of the products to the moisture and heat.
Wet granulation method is
effective for those products which are stable in heat and moisture.
Dry granulation method is used for those products which are not stable in presence of heat and moisture.
Most of the products are manufactured through wet granulation method and the first step is to weigh all the excipients and APIs.
In the next step materials are mixed together and after mixing we get a uniform blend of the powders.
The next step is to convert these fine powders into the wet mass by a process known as kneading where we add solution or solvent to the powders.
Then the wet mass is passed through the wet mill to reduce the particle size and supplied to the dryer for drying.
After drying, the sieving of granules is done and in the last step we mix all the remaining excipients with granules in the final blending step.
So the powders are converted into granules by all the above mentioned steps.
In dry granulation we use a slugging or roller compaction method instead of kneading and drying.
Apart from using wet and dry granulation another method used for tablet manufacturing is the direct compression.In this method we simply sieve the powders, mix the powders and blend is ready for compression.
Blend prepared by wet granulation,dry granulation or direct compression is now delivered to the tablet compression area.
Compression
The blend prepared is converted into the solid unit mass by application of pressure using the tablet compression process.
The tablet compression process is completed by using a tablet compression press or tablet compression machine .
The process of converting the powders or granules into solid unit mass or tablets is completed into various stages.
The tablet compression starts by addition of a product to the hopper and the powder or granules from the hopper are supplied to the federer of the compression machine.
From feeder these powders or granules are filled into the cavity and this process is known as filling or feeding stage of the compression.After filling or feeding the weight is adjusted as per requirement and after weight adjustment the third stage is the compaction where we apply the pressure over the filled product to form the tablet.In the last step of the tablet compression the tablet is removed out of the die cavity and in this way our powders or granules are converted into the tablets.
Coating
When the tablets are compressed these are ready for the coating. Coating is applied depending upon the requirement. Sometimes we do not apply the coating over the tablets so these tablets where we do not apply coating are known as core tablets or uncoated tablets.
For uncoated tablets the manufacturing process is completed after compression and these tablets are now ready for the packaging meaning these are delivered to the blistering area.
Those tablets which require coating are delivered to the tablet coating area.
Coating over tablets is applied due to a number of reasons mainly is to mask the taste,environmental protection or to alter the drug release pattern.
Types of tablet coating are,
- Film Coating
- Sugar Coating
- Enteric Coating
- Drug Coating
Tablet coating process is completed by using tablet coaters where we add our compressed tablets into the tablet coating pan and suspension of polymer and other excipients is prepared as per tablet coating formulation.
The coating suspension is applied to the rotating bed of the tablets after atomization, the hot air is applied which results in evaporation of the solvent and solid material starts to accommodate over the tablet surface.
This process continues until the required weight gain is achieved.
In this way our tablet coating process is completed and these tablets are ready to deliver for packaging meaning they are sent to the blistering department.
Conclusion
The tablet manufacturing process starts from the powders and undergoes various steps of granulation, compression and coating.In granulation we convert powders into the granules & then these granules are compressed to manufacture tablets.
Compressed tablets are now ready for the coating where we apply a thing there of the polymer over the tablet surface and the coating process is completed.So the manufacturing of tablets in the pharma industry is completed in three main steps of granulation, compression and coating.