Wet milling of API Powders differs from jet milling
Key Differences
- Medium:
- Wet Milling: Uses a liquid medium (solvent) to suspend the API.
- Jet Milling: Uses high-pressure gas (typically air or nitrogen).
- Mechanism:
- Wet Milling: Particle size reduction occurs through shear, impact, and attrition within the liquid.
- Jet Milling: Particle size reduction occurs through high-velocity collisions between particles.
- Environment:
- Wet Milling: Occurs within a liquid environment.
- Jet Milling: Occurs in a dry, gaseous environment.
Comparative Chart
| Feature | Wet Milling | Jet Milling |
| Medium | Liquid | Gas |
| Mechanism | Shear, impact, attrition | Particle-particle collisions |
| Heat Generation | Liquid helps dissipate heat | Potential for heat generation |
| Suitability for Heat-Sensitive APIs | Good | Can be problematic |
| Suitability for Static-Sensitive APIs | Good | Can be problematic |
| Particle Size Control | Good, influenced by processing parameters | Good, influenced by gas pressure and flow |
| Risk of Contamination | Potential from liquid medium | Potential from gas or equipment |
| Yield Loss | Typically lower | Potential for higher yield loss |
| Solvent usage | requires solvents | does not require solvents |
| Containment requirements | Generally less stringent | Can require more stringent containment, especially for potent compounds |
Pharma-compliant design – with Wahal validation concept
The qualification documents DQ, IQ, OQ that are required for validation or the certificates for the process-relevant machine components such as calibration- and materials certificates are available for all Wahal high shear mixer. On request, we can also carry out the Factory Acceptance Test in our factory or the Site
Acceptance Test at your production site
Advantages and Disadvantages
Wet Milling
- Advantages:
- Effective for heat-sensitive and static-sensitive APIs.
- Can provide a narrow particle size distribution.
- Liquid medium aids in heat dissipation.
- Allows for inline processing with crystallization.
- Generally lower yield loss.
- Disadvantages:
- Requires the use of solvents.
- Potential for contamination from the liquid medium.
- Requires a drying step after milling.
- In summary:
The choice between wet milling and jet milling depends on the specific properties of the API and the desired particle size. Wahal's Wet milling is often preferred for heat-sensitive or static-sensitive materials, Wahal can also design rotor stator systems in tandem with bead mills eliminating the need of any kind of other equipment and can bring down the particle size upto 100 nano metres d90. please contact us for more information.
