Poor Flow
Causes: Remedies
- Too many fines in wet Granulation: Reduce fines
- In direct compression, the particle size of drug or excipients too small and/or of shape that will not flow:
- Select larger particle size; use Avicel PH-102 or PH-200 in place of PH-101 or other excipients.
- Add glidant (0.1% to 0.5%) (e.g., Cab-O-Sil®, Aerosil)
- Use induced or force-feed mechanism on press
- Change particle shape of active ingredient to one that is more likely to flow.
- Poor inherent flow:
- Add 0.1% to 0.5% glidant
- Dry granulate (by slugging or roller compacting) with a mixture of Avicel PH-101, Cab-O-Sil, and magnesium stearate.
- Atmospheric moisture adsorption:
- Process in low humidity atmosphere
- Add moisture absorber (e.g., 0.1% to 0.5% calcium silicate, Cab-O-Sil, Syloid)
Flooding
Causes: Remedies
- Excessive flow properties (fluidization) of one or more components (could be from an excess of glidant or lubricant):
- Identify causative components and exclude or modify particle size.
- Select a narrow range of particle sizes; avoid excess fines.
- Flow is erratic and the feed frame is flooded at times: Use an induced or force-feed mechanism on the press, which may control flow.
Particle Segregation
Causes: Remedies
- Particle size range of mix too wide: Use a narrower particle size range of ingredients.
- Too wide a density difference in mixed particles: Control differences in density of Particles.
- Mixer too vigorous; produces fines: Use a mixer with a gentler mixing action.
- Use of vibrators (to promote flow from hopper): Use force-flow feed mechanisms rather than hopper vibrators
- Excessive machine vibration: Isolate hopper from tablet machine
Tags
Production
