Pharmaceutical Pin Mill
Dry Micronization to D90 Under 8 Microns. Frewitt PMC and PMV Series.
Overview
Frewitt’s pin mills achieve dry micronization to D90 under 8 microns in a single pass, without a separate air classifier. This makes them a mechanical alternative to jet milling for APIs and excipients where tight particle size control directly affects dissolution rate and bioavailability.
The PMC-160 is the compact model, handling batch sizes from 50 g up to 2 kg or continuous throughput up to 50 kg/h. At 350 kg, it fits into lab and pilot environments. The PMC-260 is the production platform at 1,100 kg, with a double screw feeder designed for poor-flowing powders and an integrated cyclone filter with automatic pressure-impulse cleaning. Both models accept interchangeable milling heads, so a facility can run either the PMC-160 or PMC-260 head on the larger platform.
For applications requiring the finest particle size and inherent safety, the PMV-320 is a patent-protected vacuum pin mill achieving D90 under 6 microns at up to 1,000 kg/h. The vacuum process eliminates explosion risk entirely, requires no inerting, and integrates dosing, conveying, cooling, and filtration into a single footprint. Automated wash-in-place is standard.
All pin mill models are available with cryogenic cooling. The CryoFeeder CF-25 module uses direct liquid nitrogen injection to chill material before milling, enabling brittle fracture of heat-sensitive, elastic, or waxy compounds that resist conventional dry milling.
Key Specifications
| Particle Size (PMC) | D90 < 8 µm |
| Particle Size (PMV-320) | D90 < 6 µm |
| Throughput (PMC-160) | 50 g batch to 50 kg/h continuous |
| Throughput (PMC-260) | 2 to 150 l/h |
| Throughput (PMV-320) | 50 to 1,000 kg/h |
| Containment (PMV-320) | OEB 5 capable (< 1 µg/m³) |
| Explosion Risk (PMV-320) | None (vacuum process) |
| Temperature Range | -20 °C to +60 °C (cryo to -80 °C) |
| Construction | AISI 316/316L interior, GMP/FDA compliant |
| Noise (PMV-320) | < 69 dBA |
Key Features
Single-Pass Micronization
Achieves target PSD in one pass with no recirculation or separate classifier. D90 under 8 microns (PMC) or under 6 microns (PMV-320). Consistent particle size distribution from batch to batch.
Vacuum Safety (PMV-320)
The PMV-320 operates under vacuum, eliminating ignition conditions entirely. No explosion risk, no inerting required. Produces less than 69 dBA, remarkably quiet for a production mill.
Interchangeable Heads
The PMC-260 platform accepts both PMC-160 and PMC-260 milling heads. Switch between throughput ranges without a separate machine. One validation package covers both configurations.
Integrated Cooling
All models include integrated cooling as standard to prevent heat degradation of temperature-sensitive APIs during high-speed milling. Optional CryoFeeder CF-25 extends capability down to -80 °C with liquid nitrogen.
Poor-Flow Powder Handling
The PMC-260 features a double screw feeder guided at both ends with no metal contact and an integrated bridge-breaker. Handles cohesive and poorly flowing powders without feed interruption.
All-in-One Design (PMV-320)
Integrated dosing, vacuum pumps, cooling, conveying, and filtration in a single footprint. No separate cyclone or separator needed. Automated WIP is standard, not optional.
Models
| PMC-160 | Compact pin mill. D90 < 8 µm. Batch (50 g to 2 kg) or continuous (50 kg/h). 350 kg. Lab, pilot, and small-scale production. |
| PMC-160 Cryo | PMC-160 with direct LN₂ injection. Milling down to -80 °C for heat-sensitive and elastic compounds. 600 kg. |
| PMC-260 | Production pin mill. D90 < 8 µm. 2 to 150 l/h. Double screw feeder, integrated cyclone filter, FreLift column. 1,100 kg. |
| PMC-260 Cryo | PMC-260 with LN₂ cryo cooling at production scale. Down to -196 °C. |
| PMV-320 | Patent-protected vacuum pin mill. D90 < 6 µm. 50 to 1,000 kg/h. Zero explosion risk. All-in-one with automated WIP. 2,500 kg. |
Applications
- Dry micronization of pharmaceutical APIs to D90 under 8 microns
- Fine grinding of excipients and intermediates for improved dissolution
- Batch processing for clinical trial materials (50 g minimum)
- Continuous production milling up to 1,000 kg/h
- High-potency compound milling with OEB 5 containment
- Cryogenic milling of heat-sensitive, elastic, or waxy compounds
- Inline micronization between process steps
Options
- CryoFeeder CF-25 liquid nitrogen cooling module
- ATEX certification
- WIP (wash-in-place) on PMC models
- Controlled milling under inerted atmosphere
- 21 CFR Part 11 / GAMP 5 compliance
- OEB 5 containment configuration (PMV-320)
- SFS-33 screw feeder (retrofittable on PMC-160)
MHS Pharma. Northeast US Representative for Frewitt.
MHS Pharma provides direct technical representation for Frewitt across the Northeast United States. Contact us to discuss pin milling and micronization for your application.
Get in Touch