Role Of Granulation In The Pharmaceutical Tablet Manufacture Process

Posted by Michael Griffin on January 7th, 2020

Granulation is an important process used in the pharmaceutical industry and is used to produce solid drugs. It is basically a process in which powdered ingredients adhere together to form homogenous granules. It is of two types - dry granulation and wet granulation. Granulation is basically done with the help of granulators, equipment in which the powdered component is compacted by means of a compressive force, which adhere together on the application of the force.

Granulation has a big role to play in pharmaceutical processing and is an important part of the production. Small scale pharmaceutical industries often use surplus equipment for their production and packaging process. A used granulator can also manage production smoothly and it is also an affordable alternative. This guide will give you complete information about the role of granulation in tablet production.

What is dry granulation?

Dry granulation is the process of granule formation with the use of direct compaction on the powdered ingredients. This process is generally used in the granulation of components that are highly sensitive to heat or moisture. High pressure is imparted on the powdered particles, which in turn aggregates the particles together. High shear granulators or roller compactors produce large sheets of compacted granules and when the sheet is compacted enough it is compressed into tablets with a tablet press.

What is wet granulation?

In this method of granulation, a granulating liquid is added to the mix, which helps in the formation of granules. A volatile, non-toxic liquid is added to the powdered components to mass them together. Water, isopropanol and ethanol are commonly used granulating fluids and they are used individually or sometimes in a combination. Once the powdered ingredient has massed together, they are dried to remove the moisture from them and it is now ready for tablet compression.

Difference between dry and wet granulation

- One major difference between dry and wet granulation is that dry granulation compacts the ingredients without the use of any liquids while wet granulation uses a bonding liquid for the massing of particles.

- Dry granulation imparts direct compression on finely ground powdered particles to compact them while wet granulation involves mixing the powder with the help of a granulating liquid.

- Dry granulation is used when producing tablets out of moisture and heat-sensitive components. Wet granulation, on the other hand, is used to avoid the active ingredients from being destroyed.

Steps involved in wet granulation

Wet granulation technique involves the following steps:

- Sifting

In this step, the API (Active Pharmaceutical Ingredients) and the excipients are sifted with the help of a sieve, which mixes together as the sieving is done.

- Mixing

The next step involves a thorough mixing of the components. Once the components are thoroughly mixed by dry granulation. A used Fitz mill granulator is a cost-effective and efficient option for dry mixing the components. After the ingredients are mixed, a granulating fluid is added to the mix, which then combines with the components adhering them together in a rapid mixture granulator.

- Drying

A fluid bed dryer or a tray dryer is then used to dry the materials and once the components are dried they are set for lubrication.

- Lubrication

This is the last step of wet granulation where the compacted particles are lubricated to further increase the adhesion of the API. Once the components are lubricated, they are ready for tablet compression.

Steps involved in dry granulation

This type of granulation does not use any granulating liquid and is often used to compact ingredients that are sensitive to heat and moisture.

- Dispensing

This is the first step of dry granulation where the API and the excipients are dispensed in a specified amount.

- Mixing or blending

It is the dry mixing or blending of the API and the excipients thoroughly.

- Compaction

The mixed powdered ingredients are then passed through high shear granulators or roller compactors resulting in slug formation. The slugs are then compressed into the shape of tablets.

- Milling or crushing

Once the slugs are formed, it is crushed or milled until it is thoroughly granulated. More extragranular excipients are added at this stage if required.