PHARMACEUTICAL WET GRANULATION

ORAL SOLID DOSAGE FORMS

PHARMACEUTICAL WET GRANULATION

ORAL SOLID DOSAGE FORMS

Wet Granulation is a process widely used in the pharmaceutical industry consisting of modifying the morphological properties of a powder product, altering its size, density, and fluidity.

The powder product (or products) is mixed while spraying a binder solution. This solution, combined with the mixing motion, causes the powder particles to adhere to each other forming larger particles called granules.

The binder solution can be aqueous or solvent-based, mainly ethanol and isopropanol alone or in combination, it must be volatile so that it can be removed by drying and it must be non-toxic.

The resulting product, the granule, has greater fluidity and better compaction, reducing product loss during transfer and handling, and facilitating the processing for the manufacture of oral solid dosage forms, such as tablets, capsules, or sachets.

Wet Granulation Process for Pharmaceutical Products | STE Tecpharm

MAIN REASONS FOR WET GRANULATION

Dust Reduction: reduces fine particles for better dust control during processing.
Improved flowability: improves the overall flowability of powders, which is more conducive to post-processing requirements.
Control of uniformity and particle size: you can preset the final granule size and create a consistent distribution of ingredients.
Enabling Compaction: helps to hold granules together when compressed into a tablet core.
Controlled solubility characteristics: increases control of dissolution profiles.
Higher bulk density: a control of key process parameters for specific body absorption.

This wet granulation process can be carried out by two different methods: high shear and low shear.

The choice of the granulation method will depend, on the one hand, on the application to be given to the granulate and, on the other, on the physical-chemical properties of the active principle and the excipients of the formulation, in particular on its sensitivity to humidity and heat.

HIGH SHEAR GRANULATION

In high shear granulation, the binder solution is sprayed into a container with the powder product, which is mixed by paddles creating a high-intensity interaction (high shear force).
As the solids get wet and are mixed with the movement, they bond together in an agglomeration process, forming the granules.
These granules are not uniform so they need to be sieved through a calibrating mill, guaranteeing homogeneity of shape and size.

The most common equipment for this process is the High Shear Mixer Granulator.

The resulting granule retains the moisture from the solvent and must be subsequently dried by applying heat within the same container or by means of a dryer, usually the Fluid Bed Dryer.

LOW SHEAR GRANULATION

In the case of low shear granulation, the solid product is mixed with gentle movement and combined with the spraying of the binder solution (low shear force).

The most common equipment for this process is a Fluid Bed Granulator, which also performs the final drying process.

The Fluid Bed Granulator Dryer works on the principle of fluidization. In this fluidization process, hot air is introduced, with defined pressure and flow, through a perforated bed on which the wet solid particles rest. These wet particles are lifted from the bottom and suspended in a stream of air (fluidized state).
The movement of the product in a fluidized state is combined with the spraying of a binder solution. This combination allows increasing the size of the particle, generating the granule.
Heat transfer is carried out by direct contact between the wet solid and the hot gases, which evaporate the solvent.
Finally, the granules are sieved through a calibrating mill to guarantee their uniformity in terms of size and shape.

Granulation

The movement of the product in a fluidized state is combined with the spraying of a binder solution. This combination allows increasing the size of the particle, generating the granule.

Drying

Heat transfer is carried out by direct contact between the wet solid and the hot gases, which evaporate the solvent.

MAIN PIECES OF EQUIPMENT FOR WET GRANULATION

GRANULATION LINES

THE PERFECT GRANULATION

Complete wet granulation lines for development or industrial batches. Integrates into a single frame and control panel all options for solid forms production process:
■ Mixing.
■ Granulation.
■ Drying.
■ Calibration.

High Shear Mixer Granulator for wet granulation | STE Tecpharm

HIGH SHEAR MIXER GRANULATORS

WET GRANULATION PROCESS

Designed to optimize the wet granulation process. Used to turn a fine-powder heterogeneous mixture into a uniform granulation, with increased particle size and higher density, offering proper flow and compactness properties within a short time process and with repeatability.