Lattice® NT Binders

For decades, solid dosage formats in chemical and pharmaceutical formulations have been prevalent as they provide an effortless way to manage, transport, and store highly active ingredients. Though solid formulations like tablets and pills are perceived to be used primarily by the pharmaceutical industry, more industries are also increasingly leveraging these due to their convenient and sustainable nature.

In particular, solid formulations reduce shipping weight and the need for excess packaging. As such, tablets and powders are becoming increasingly popular for industrial applications such as disinfectants, fertilizer products, and water treatment.

Although active ingredients are the most valuable components of solid formulations, it is important for formulators to use the right binders and excipients to ensure the highest product quality and efficiency. Binders and excipients play a crucial role in tablet and granule formulations by providing physical strength and structural form.

Lattice® NT Microcrystalline Cellulose for Solid Formulations

IFF's microcrystalline cellulose products, such as Avicel®, have been used in the pharmaceutical space for many years as excipients for countless tablet medications. Today, IFF has developed Lattice® NT, a microcrystalline cellulose binder designed for creating tablets and granules for industrial applications. Lattice® NT is a naturally derived product made from alpha cellulose content originating from wood pulp. The image below illustrates alpha cellulose, composed of millions of microfibrils that contain paracrystalline and crystalline regions (A and B).

The crystalline regions are rigid, linear cellulose chains, while the paracrystalline regions are amorphous, flexible cellulose chains. Lattice® NT is manufactured by processing and drying the crystalline regions, creating extremely porous microcrystalline cellulose.

In particular, the combination of high porosity and large surface area makes Lattice® NT microcrystalline cellulose highly effective as a binder and processing aid for creating tablets and granules.

Tablet Binders

Typically, the first step of producing tablets or granules is to combine active ingredients with binders and other solid contents. Lattice® NT binders bind formulation components together, providing better shape and homogeneity. Their high porosity makes them highly compactible, giving them the ability to develop tablets with the desired shapes and sizes more easily. In addition, as mentioned, Lattice® NT binders have a high surface area, creating a larger interface that active ingredients and fillers can bind to and achieve hydrogen bonding with the cellulose structure, giving the tablet the required strength.

Due to their high porosity and surface area, Lattice® NT binders also promote rapid, even wetting. This is useful in both tablets and granules to ensure that the active ingredient gets distributed in a homogeneous, controlled manner throughout the liquid phase.

Granulation Processing Aids

Both wet and dry granulation techniques are used to create granules of a desired size for tablet production. They increase the workability of solid ingredients (typically powders), allowing them to flow and be poured more easily into tablets. Granulation also helps to achieve a more even dispersion of active ingredients.

In dry granulation, Lattice® NT primarily functions as a binder. Solid ingredients are mixed, forming them into larger aggregates called slugs. The slugs are then forced through a screen to create granules of the desired size. Here, Lattice® NT provides the anticaking properties necessary to prevent granules from sticking together, reducing the efficiency of compaction.

Wet granulation is the preferred method for active ingredients that are not heat sensitive. This process involves mixing the solid ingredients and placing them into a fluid bed granulator that gradually introduces a liquid to bind powders together and induce granulation. Here, the granules grow larger as more liquid is added to the powder mixture. Fine control over granule size is always desirable. However, it is often difficult to achieve because the association between liquid volume and granule size is not linear. As such, there is always a risk of adding too much liquid, turning granules into a slurry.

Lattice® NT is critical in assisting wet granulation through a high surface area and large absorptive capacity. It enables liquid to be absorbed by powders at a very even rate, correlating strongly with mean granule size. As shown below, this property allows formulators to have better control over the granulation process.

Lattice® NT also widens the processing window for wet granulation by acting as a buffer for water, extending the endpoint at which slurry formation occurs. The chart below compares two formulations, one with Lattice® NT-50 and one without. Torque correlates directly with granule size because of the increased cohesive strength gained when water is added. As indicated by the graph, more water can be absorbed over a longer period, providing a more gradual change in granule size. This affords formulators and operators a larger window of time to adjust granule size to the exact specifications they need.

Lattice® NT Grades

There are several grades of Lattice® NT binders and processing aids available in several different average particle sizes. The ideal Lattice® NT binder has an average particle size roughly equal to the other solid components in the formulation. However, based on specific applications, general recommendations are offered where Lattice® NT is to be used as either a binder or process aid for tablets, extruded products, and granules. The exact use level for each grade will depend on the concentration of other contents in the formulation, such as the dosage of the active ingredient.

Summary

Lattice® NT is a naturally derived binder and process aid essential for creating high-quality, robust solid formulations for a variety of industrial tablet and granule applications. It offers highly effective binding capabilities due to its high porosity and surface area, allowing solid formulation ingredients to coalesce and form tablets with high strength and homogeneity. It is also an excellent processing aid for granulation, allowing for finer granule size control and anticaking properties.

Click below to request a sample of Lattice® NT for your granule or tablet formulation today.