Wet Granulation Processes

Wet granulation is a pharmaceutical unit operation whereby a liquid or binder solution is sprayed onto a powder blend to improve the flow, compressibility, and content uniformity of the blend, prior to tabletting.

Improvement of flow and compressibility can be important in extended/controlled release matrix formulations where polymers with fine particle size are typically utilized to ensure rapid, reproducible polymer hydration.

Contact Colorcon® today for assistance in the wet granulation of METHOCEL™ Premium Cellulose Ethers, POLYOX™ Water Soluble Resins, and ETHOCEL™ FP Premium Ethylcellulose Polymers.

Wet Granulation Aids

METHOCEL™ can be used at low concentrations as a binder in wet granulation processes, which is advantageous for high dose drugs. They produce hard tablets with low friability, without negatively affecting tablet disintegration. METHOCEL™ products allow the reduction of compression force, an important factor in extending the life of tooling and equipment.

Dow Excipients in Binder Granulations

Dow Granulation Literature

Starch 1500® Partially Pregelatinized Maize Starch is an alternative to native corn starch or polymers and is useful as both a binder and a disintegrant in wet granulated formulations. Starch 1500 is well suited for use in fluid bed granulation, as well as low shear and high shear wet granulation.

 
The Use of Starch 1500 as a Binder and Disintegrant in Wet Granulation

Colorcon's unique manufacturing process results in the most effective functional balance for Starch 1500. Due to the low solution viscosity, binding and disintegration properties, Starch 1500 allows for process flexibility. This flexibility includes the ability to dry-blend Starch 1500 with other ingredients before adding water, or dispersing a portion in cold water. The choice of where to add the starch excipient depends greatly on the formulation and the process used, as well as the desired finished dosage characteristics.

Dry Addition
The cold water soluble fraction of Starch 1500 provides unique benefits for the granulation process. The main advantage is that it can be dry blended with other ingredients and granulation can be accomplished by the addition of water. This simplifies the process by eliminating the need to prepare binder slurries. The approach is similar to using fully pregelatinized starches, although Starch 1500 can reduce the risk of over-granulation and at the same time provide the formulation with an effective intragranular disintegrant.

Binder Slurry
A slurry of Starch 1500 in cold water provides effective binding properties at higher solids and lower viscosity than traditional starch pastes, which must be heated and prepared at lower concentrations. Processing costs are reduced by eliminating the time and expense of preparing traditional binder solutions. In addition, granulations using Starch 1500 as a binder give excellent tablet hardness and fast disintegration.

Contact Colorcon to learn how using Starch 1500 can reduce process time and cost while preserving optimal properties in a well constructed formulation.

METHOCEL™, POLYOX™ and ETHOCEL™ are registered trademarks of Dow Wolff Cellulosics