Page 10 - Pharmaceutics III_ 02-06-01304_Fall 2025_ Pharm D_Electronic book

Ingredient Role Note

Base Source of $\text{CO}_2$ (e.g., Sodium
Bicarbonate) [cite: 538]

Binding Liquid Binder (e.g., Alcohol, or an Water should be minimized
alcohol/water mixture) to prevent a premature
reaction.

Equipment Mortar and Pestle, Sieves (e.g., 4-12
mesh range ), Drying oven, Balance.

2. The Granulation Procedure

The key to the wet method is controlled mixing to create the correct dampness for forming
granules without triggering a full effervescent reaction.

• Step 1: Powder Preparation and Blending

o Reduce all ingredients to a uniform, fine powder using a process like trituration .

o Geometrically dilute the potent drug (if used) into the bulk excipient powders
(acids and base) using a mortar and pestle to ensure uniform distribution .

o Blend all dry ingredients thoroughly.

• Step 2: Wetting the Powder Mass

o Slowly add the binding liquid (e.g., alcohol) to the dry, blended powder mixture
in the mortar .

o Mix the powders until a damp, plastic mass is formed. The mass should hold its
shape when pressed but should not be excessively wet or sticky.

o Critical Note: Perform this step rapidly to minimize contact time between the
powders and the moisture.

• Step 3: Sizing (Granulation)

o Pass the damp mass through a sieve (typically a coarse-mesh sieve, e.g., 4 or 6
mesh) to break the mass into wet granules .

o Spread the wet granules on a drying tray.

• Step 4: Drying and Final Sizing

o Place the wet granules in a low-temperature drying oven or a fluid-bed dryer to
remove the remaining moisture .

o Ensure complete drying to prevent future moisture-induced effervescence
during storage, which can affect stability .

o Once fully dry, pass the granules through a final sieve (e.g., 10 or 12 mesh) to
achieve the final, uniform granule size .

3. Benefits of the Wet Method

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