Pharmaceutical Cryo Milling
Cryogenic Size Reduction Down to -196 C. Frewitt PMC Cryo and CryoFeeder.
Overview
Some materials cannot be milled at room temperature. Elastic compounds deform instead of fracturing. Waxy materials smear. Heat-sensitive APIs degrade from friction. Cryogenic milling solves this by cooling the material below its glass transition temperature with liquid nitrogen, making it brittle enough to fracture cleanly under impact.
Frewitt offers two approaches to cryo milling. Dedicated cryo pin mills (PMC-160 Cryo and PMC-260 Cryo) have direct LN₂ injection built into the milling chamber. The PMC-160 Cryo reaches -80 °C with throughput up to 30 kg/h. The PMC-260 Cryo is the production platform, reaching -196 °C with throughput up to 150 l/h and interchangeable milling heads.
For facilities that only need cryo occasionally, the CryoFeeder CF-25 is a standalone cooling module that pairs with any existing Frewitt mill. It pre-cools material down to -195 °C using automatic LN₂ regulation before feeding it into the mill. At 250 kg, it adds cryo capability to an existing line without replacing the mill.
Both approaches achieve D90 under 8 microns. The dedicated cryo mills are the right choice for continuous cryo production. The CryoFeeder is the retrofit option when cryo milling is needed for specific products but not the primary use case.
Key Specifications
| Particle Size | D90 < 8 µm |
| Temperature (PMC-160 Cryo) | Down to -80 °C |
| Temperature (PMC-260 Cryo) | Down to -196 °C |
| Temperature (CryoFeeder CF-25) | Down to -195 °C |
| Throughput (PMC-160 Cryo) | Up to 30 kg/h |
| Throughput (PMC-260 Cryo) | 2 to 150 l/h |
| Throughput (CryoFeeder CF-25) | 1 to 35 kg/h |
| LN₂ Regulation | Automatic on all models |
| Construction | AISI 316/316L interior, GMP/FDA compliant |
| Insulation | Double-walled stainless steel superinsulation + polymer |
Key Features
Direct LN₂ Injection
The PMC Cryo mills inject liquid nitrogen directly into the milling chamber, not just the feed zone. This ensures the product stays below its glass transition temperature throughout the entire milling process.
Automatic LN₂ Regulation
All cryo models automatically regulate liquid nitrogen flow to maintain consistent process temperature. No manual adjustment needed. The system guarantees product immersion at -195 °C.
Retrofit Capability
The CryoFeeder CF-25 is a standalone 250 kg module that adds cryo to any existing Frewitt mill. No need to replace the mill or change the line layout. Connects via standard interfaces.
Double Insulation System
Double-walled stainless steel superinsulation plus polymer thermal insulation prevents nitrogen evaporation, minimizes LN₂ consumption, and ensures operator safety.
Interchangeable Heads (PMC-260 Cryo)
The production cryo platform accepts both PMC-160 and PMC-260 milling heads. Run different throughput ranges on the same machine, cryo or ambient, with one validation package.
Same Footprint as Standard
The PMC-260 Cryo has the same dimensions and weight as the standard PMC-260. Cryo infrastructure is integrated, not bolted on. Drop-in replacement for existing installations.
Models
| PMC-160 Cryo | Compact cryo pin mill. D90 < 8 µm. Down to -80 °C. Up to 30 kg/h. Direct LN₂ injection. 600 kg. |
| PMC-260 Cryo | Production cryo pin mill. D90 < 8 µm. Down to -196 °C. 2 to 150 l/h. Interchangeable heads, double screw feeder, cyclone filter. 1,100 kg. |
| CryoFeeder CF-25 | Standalone cryo cooling module. Down to -195 °C. 1 to 35 kg/h. Pairs with any Frewitt mill. 250 kg. The retrofit option. |
Applications
- Milling elastic and fibrous materials that deform at room temperature (polymers, rubber, waxes)
- Processing heat-sensitive APIs that degrade under friction
- Cryogenic micronization of hard and crystalline compounds
- Materials with low glass transition temperature requiring embrittlement
- Production-scale cryo milling up to 150 l/h
- Retrofitting cryo capability onto existing Frewitt milling lines
Options
- ATEX certification
- WIP (wash-in-place)
- Controlled milling under inerted atmosphere
- 21 CFR Part 11 / GAMP 5 compliance
- SFS-33 screw feeder (retrofittable on PMC-160 Cryo)
- CIP for screw feeder (PMC-260 Cryo)
MHS Pharma. Northeast US Representative for Frewitt.
MHS Pharma provides direct technical representation for Frewitt across the Northeast United States. Contact us to discuss cryogenic milling for your application.
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