Applications of Electromagnetic Vibratory Feeders in the Pharmaceutical Industry
Industry Background
Powder raw materials used in the pharmaceutical industry—ranging from active pharmaceutical ingredients (APIs) to various excipients such as starch, lactose, microcrystalline cellulose, and magnesium stearate—exhibit widely varying bulk densities, with flow properties spanning from “as free‑flowing as water” to “completely non‑flowing.” Moreover, the same equipment often processes Product A one day and Product B the next; if residues are not thoroughly removed during changeovers, cross‑contamination can directly jeopardize patient safety.
The core requirements of GMP for this type of equipment can be summarized in three points: Cleanable (The equipment must be capable of thorough cleaning, and the cleaning process must be verifiable.) No blind spots (No blind spots where materials can accumulate), Traceable (All aspects, including equipment materials, surface treatments, and contact areas, must be supported by documented records for verification.) In the early stages, many domestic manufacturers relied on standard carbon‑steel feeders; under these three criteria, virtually all of them failed. Transitioning to compliant equipment is only a matter of time.
In addition, the API manufacturing workshop and certain traditional Chinese medicine extraction workshops use organic solvents such as ethanol and ethyl acetate, or process plant powders containing oils; these environments pose an explosion risk, requiring equipment to meet stringent explosion-proof standards. The ATBR FZL-EX explosion-proof series was specifically developed for such applications, retaining all the GMP‑compliant design features of the FZL series while achieving explosion protection ratings of Ex mb ⅡC T6 Gb and Ex mb ⅢC T85℃ Db.
The ATBR electromagnetic vibratory feeder’s primary applications in the pharmaceutical industry include: weighing and batching active pharmaceutical ingredients and excipients; pre‑blending feed for tablet and capsule production; continuous feeding during granulation and coating processes; and weighing and packaging of finished products or intermediates.
Process Stages and Solutions
1. Weighing and blending of active pharmaceutical ingredients and excipients—GMP compliance is a prerequisite.
The production of solid dosage forms begins with weighing and batching. In a batch of tablets, the active ingredient, diluents, binders, disintegrants, and lubricants are accurately weighed according to the formulation and then transferred to the blending unit. The active ingredient is present in small quantities but requires high precision, while the lubricant (magnesium stearate) is used in very low amounts, yet its blending performance significantly affects tablet hardness.
Traditional manual weighing and batching poses three risks: accuracy depends on the operator’s experience; the thoroughness of cleaning between batches cannot be objectively verified; and every step in the process requires manual record-keeping, which can lead to transcription errors.
Solution for the ATBR FZL series pharmaceutical-grade feeders:
316L stainless steel contact surface, Ra < 0.2 μm All components in contact with the material—namely, the vessel, side panels, and discharge end—are fabricated from 316L stainless steel, with the internal surfaces mirror‑polished to a surface roughness of Ra < 0.2 μm. All welds on the vessel are subjected to high‑standard polishing and pickling, effectively eliminating the risk of material retention in weld depressions. This level of surface finish far exceeds the typical requirements of the FDA and China’s GMP for equipment contacting oral solid dosage forms; material‑contact surfaces virtually prevent powder adhesion, and post‑CIP cleaning residue levels can be consistently maintained below 10 ppm.
Rapid cleaning of conveyance pipelines Thanks to the inherent advantages of the vibratory feeder, materials move spontaneously within the chute, eliminating the need for blades to propel them as in a screw conveyor. The front and rear sealing baffles of the vibratory feeder are secured with quick‑release clamps, allowing for rapid cleaning using simple tools.
Equipment awaiting shipment for the pharmaceutical industry
2. Granulation of Tablets/Capsules—Continuous and Uniform Feeding
Granulation is a critical step in the production of solid dosage forms. In wet granulation, the powder is first mixed with a binder solution to form a soft mass, whereas dry granulation relies on roller compaction to directly compress the powder into thin sheets, which are then crushed. Regardless of the method, the consistency of the feed rate and the accuracy of the dosage input directly affect the particle size distribution and the dissolution performance of the final tablets.
Application of FZL-series feeders in this stage:
The blended powder (already weighed) is discharged from the hopper into the feeder trough, and the feeder delivers it to the granulator at a set rate, ensuring uniform feeding and preventing sudden large‑volume surges that could result in the soft material being either too dry or too wet.
For materials with poor flowability, such as starch and microcrystalline cellulose, a specially designed trough geometry is employed, combined with high-frequency, small-amplitude vibrations to prevent bridging and ensure continuous feeding without interruptions.
It is interlocked with the granulator’s feed‑in signal: when the granulator requests material, the feeder automatically starts; once the hopper is full, it stops automatically, with no manual intervention required throughout the entire process.
3. Feeding the coating machine—small quantities, precise dosing, and contamination prevention
In the film-coating process, coating material (pre‑mixed coating powder) must be fed continuously into the rotating coating pan. The feed rate is typically a few kilograms per batch, but the material should be added evenly—never dumped in all at once—otherwise the coating thickness will be uneven and the appearance will fail to meet specifications.
The FZL series small feeders (small‑size models with trough widths of 100–200 mm) are suitable for this application:
The hopper has a small capacity and is designed to work in tandem with the coating machine, preventing moisture absorption caused by an excessive amount of material awaiting processing.
Amplitude fine-tuning enables micro‑dosing, with the dosing rate controllable down to the gram‑per‑minute level.
Made entirely of 304/316L stainless steel; the coating powder does not contaminate the tank, and cleaning is quick.
A dust‑extraction system can be installed at the material‑feeding end to prevent coating powder from becoming airborne during feeding, thereby safeguarding the cleanliness of the cleanroom environment.
4. Traditional Chinese Medicine Extraction and Intermediate Processing—Catering to Both Extract Powders and Plant Powders
The production of solid Chinese medicinal preparations—such as granules and tablets—requires first grinding the raw herbs, extracting their active constituents, concentrating the extract, and then spray-drying it to obtain an extract powder. This powder is subsequently blended with excipients to form granules and compressed into tablets. Due to its strong hygroscopicity, high viscosity, and tendency to cake, the extract powder is notoriously difficult to handle during feeding.
The metal blades of conventional screw feeders stir up caked extract powder, causing it to adhere all over the chamber walls, and a single cleaning can take half a day.
The electromagnetic vibrating feeder boasts the advantage of a trough design with no rotating parts; under vibration, the material advances in a “micro‑throwing” motion, while viscous extract powders slide along the polished inner wall with a surface roughness of Ra < 0.2 μm, resulting in significantly less adhesion compared to screw conveyors. During cleaning, a single bucket of hot water is sufficient to achieve thorough rinsing, reducing the cleaning time from half a day or more to under 20 minutes.
For plant powders—coarse powders obtained by grinding medicinal materials, typically ranging from 100 to 200 mesh—vibratory feeding is equally suitable; it can be used in conjunction with a dust‑extraction hood to prevent powder from becoming airborne. In certain traditional Chinese medicine extraction workshops that employ organic solvents, the FZL‑EX explosion‑proof series should be selected, with all electrical components fully compliant with explosion‑proof certification requirements to ensure workplace safety.
Application of the FZL Series in Raw Material Packaging and Metering
Technical Features
GMP-grade material and surface treatment. All material-contact surfaces are made of 316L stainless steel and mirror-polished to a surface roughness of Ra < 0.2 μm. All welds undergo high‑standard polishing followed by acid pickling to eliminate weld scars, pits, and microscopic crevices, thereby fundamentally preventing material residues and microbial growth. This design meets the highest FDA and Chinese GMP requirements for equipment in contact with oral solid dosage forms. Electromagnets are installed in a manner that isolates them from the process material, ensuring that electrical components do not come into contact with the product.
Online cleaning is highly efficient, and the validation data are complete. The mirror‑finish chamber interior, combined with a fully enclosed design, enables thorough removal of residues through CIP in‑line cleaning. A corresponding standard operating procedure (SOP) is provided, and worst‑case cleaning validation data—obtained using the swab method with residues below 10 ppm—supports customers in completing equipment qualification.
Precise batching, system integration. Dual-speed feeding with closed-loop weighing ensures batching accuracy within ±0.3%. It supports PLC/DCS control and can integrate with MES/ERP systems, enabling end-to-end digital recording of the batching process and meeting GMP requirements for electronic batch records.
Applicable to cleanrooms. The equipment’s exterior surface treatment meets the cleanliness requirements of cleanrooms (no sanitary dead zones; smooth surfaces that can be wiped down for disinfection). Application examples are available for Class D and Class C cleanrooms. Electromagnetic coils and wiring can be configured with different protection ratings to suit the specific cleanroom class.
Explosion-proof type available. For API synthesis, organic solvent‑based environments, or workshops containing flammable dusts, the FZL‑EX explosion‑proof electrical components are fully equipped with explosion‑proof certified parts, meeting the relevant explosion‑proof zone requirements while maintaining full GMP‑compliant design and ensuring safety and regulatory compliance.
Handling high‑difficulty materials. For materials with poor flowability and a tendency to adhere to vessel walls—such as extract powders, microcrystalline cellulose, and talc—mature application solutions are available, including specialized hopper designs and optimized vibration parameter settings.
FZL-EX Series Explosion-Proof Electromagnetic Vibratory Feeder (Driver Enclosure Type)
Actual operational data
The following are the operating data for a certain batching and feeding system (using a total of 18 ATBR FZL-series feeders):
Indicator
Data
Active ingredient weighing accuracy
±0.2%
Auxiliary materials (bulk) batching accuracy
±0.3%
CIP cleaning time per unit of equipment
≤15 minutes
Residue Limits for Cleaning Validation
<10 ppm (swab method)
Risk of cross-contamination during changeover
Meets GMP requirements (supported by validation data)
Annual equipment operating time
>7,500 hours
Average annual maintenance man-hours per unit
<2 hours
Conclusion
In the pharmaceutical industry, equipment selection—whether in terms of precision or throughput—is merely a prerequisite; GMP compliance is the true threshold. A reliable feeder must pass equipment qualification, support cleaning validation, generate complete electronic records, and ensure that residual contamination remains consistently below specified limits during changeover and cleaning. Once these requirements are met, factors such as precision and durability become far less challenging.
ATBR’s equipment design for the pharmaceutical industry, the process is driven backward from GMP requirements—rather than simply adapting off‑the‑shelf industrial equipment. If you are selecting ingredient‑handling equipment for a new cleanroom or need to replace existing equipment that has failed validation, please contact us. We can provide initial equipment‑selection recommendations and schematic diagrams.
