Wet Granulation: Recommended Excipients 

Wet Granulation: Recommended Excipients 

Wet granulation is a widely used granulation technique in the pharmaceutical industry, where a liquid binder (e.g., water, ethanol, or a solution) is used to agglomerate powder particles, improving flowability, compressibility, and uniformity. Below are recommended excipients and a technical breakdown.  

Recommended Excipients
1. Fillers (Diluents)
Microcrystalline Cellulose (MCC): e.g., Avicel PH series, offers excellent compressibility and moisture absorption, suitable for direct compression or wet granulation.  
Lactose: Spray-dried lactose (e.g., Fast-Flo) has good flowability; monohydrate lactose is stable but may be moisture-sensitive.  
Mannitol: Suitable for chewable tablets, with good solubility but slight hygroscopicity.  
Pregelatinized Starch: Partially pregelatinized starch (e.g., Starch 1500) acts as both a binder and disintegrant.  

2. Binders
Hydroxypropyl Methylcellulose (HPMC): Low-viscosity grades (e.g., E5, E15) are suitable for wet granulation, producing strong granules.  
Polyvinylpyrrolidone (PVP): PVP K30 is commonly used, soluble in water or ethanol, ideal for moisture-sensitive drugs.  
Starch Paste: Traditional binder (e.g., corn starch paste), cost-effective but with weak binding capacity.  
Sucrose Solution: High concentrations (50-70%) are used in traditional Chinese medicine pills but may prolong drying time.  

3. Disintegrants
Croscarmellose Sodium (CCNa): Superdisintegrant, typically added externally (after granule drying).  
Crospovidone (PVPP): Strong water absorption and swelling, suitable for moisture-sensitive formulations.  
Sodium Starch Glycolate (CMS-Na): Rapid swelling but requires controlled usage (typically 1-5%).  

4. Lubricants/Glidants
Magnesium Stearate: Standard usage 0.5-1%; excessive amounts may hinder disintegration.  
Talc: Acts as both a glidant and lubricant but may affect content uniformity.  
Silicon Dioxide (Colloidal SiO₂)**: e.g., Aerosil 200, improves granule flowability.  

5. Other Excipients
pH Adjusters: e.g., citric acid, sodium bicarbonate (for drug release or stability control).  
Wetting Agents: e.g., sodium lauryl sulfate (SDS), used for hydrophobic drug granulation.