Wet Granulation

Secondary manufacturing processes are those processes responsible for turning the active pharmaceutical ingredient (API) into a dosage form. These processes include sizing, milling, blending, compression and coating operations. The end result of these processes is to produce a drug which is

• Safe: physically and chemically stable

• Elegant: Well-shaped and free from defects

• Pure: Free from contaminants

• Efficacious: has the ability to release the active ingredients in a predictable and reproducible fashion.

Granulation is a secondary manufacturing process employed in tablet manufacture. Benneth and Cole 2003 describes granulation as the blending of the drug ingredient with binders, fillers and colouring agents as well as a series of process designed to improve the bulk density, size, uniformity and stability of the drug mixture. Examples of these are direct compression, wet granulation, dry granulation, spray granulation and combined granulation processes. This report describes the wet granulation process of tablet manufacture.

2.0 STAGES IN THE WET GRANULATION PROCESS:

2.1. Bulk Container: this is an Intermediate storage vessel for holding the materials before the next operation.

2.2. Solution Mixer: This stage involves thoroughly mixing the diluents, solvents, binder solutions and wetting agents to achieve a uniform solution composition before addition to the drug powders. This prevents segregation of the constituents in the mixer-granulator.

2.3. Dry Mill: The dry mill thoroughly blends the dry active ingredient powders, (Hickey and Ganderton, 2010). This decreases the environmental hazards for the working personnel due to dust formation from toxic materials and reduces the bulk volume