Application
Gravimetric Feeding in Pharmaceutical Production
Answer in brief
In continuous pharmaceutical manufacturing the feeders are the process.
Blend uniformity is produced by the feed rates rather than by a mixer, so a feeder that drifts produces an out-of-specification product rather than a flow problem.
- Match the feeder size to the rate; oversized feeders lose accuracy.
- Control vibration, because load cells measure it too.
- Treat refill behavior as part of the validated process.
Reviewed October 21, 2026 · Updated October 21, 2026
The problem
Active ingredients are dosed at low rates with tight tolerances, and the weighing signal is sensitive to structural vibration, air movement and refill disturbances.
During refill the feeder runs blind, and a density change in that window becomes a dosing error.
Desired outcome
A feeder that holds the set rate across the required turndown, with an inlet condition it can cope with and an installation that does not corrupt the weight signal.
Process approach
Loss-in-weight feeders with the discharge device matched to the powder, twin screws for cohesive materials and vibratory trays for fragile ones, give the required control.
The installation decides whether the catalogue accuracy is achieved: isolated supports, flexible connections and refill that does not shock the hopper.
In a contained line the feeder is also a containment component, which affects the hopper design, the refill connection and the cleaning method.
- Feeder size chosen for the rate, with the right turndown rather than the largest range.
- Vibration isolation and flexible connections designed, not improvised.
- Refill strategy that limits blind time and avoids density shifts.
Selection factors
- Rate range and the accuracy the product specification requires.
- Powder flow behavior, including aeration and bridging.
- Vibration at the installation position.
- Containment band and the cleaning method.
- Refill source and its effect on the weight signal.
Common failure modes
- Feeder oversized for the rate, losing accuracy at the low end
- Structural vibration corrupting the weight signal
- Density change during refill blind time
- Refill valve shocking the hopper and disturbing the control
Partner with powderbulkvideos.com
Put a relevant technical solution in this decision path.
Connect your company and video evidence with clearly labelled visibility where engineers evaluate this material, application, industry or product.
Related content
Continue exploring
Move from this page to the companies, videos and technical topics that add useful context.
Companies
Videos
Gericke AG
Continuous Mixer Gericke GCM
Gericke shows the GCM continuous mixer, which combines radial and axial mixing for throughputs that range from 10 l to 150,000 l/h.
Total reach: 4,517
Gericke AG
Gericke: GFS Formulation Skid and Tablet Press
This video presents the Gericke Formulation Skid (GFS) combined with a tablet press, showing how pharmaceutical formulations move from blending through downstream processing in one controlled, scalable setup. The system runs semi-continuously or fully continuously and targets development, scale-up, and technology transfer.
Total reach: 3,769
Glatt
MODCOS Direct Compression
Glatt shows the MODCOS line for continuous direct compression, which can integrate up to three mixers and ten feeders on the way from powder to tablet.
Total reach: 2,646