Filling gelatin capsules with powder remains one of the most widely used dosage forms in the pharmaceutical, nutraceutical, and herbal medicine industries. Whether you're producing dietary supplements, herbal extracts, or prescription medications, capsule filling allows for accurate dosing, easy swallowing, and flexible formulation.
To fill gelatin capsules with powder, you can use either a manual capsule filling tray for small-scale needs or an automatic capsule filling machine like the NJP Series from LTPM CHINA for industrial production. Successful capsule filling requires flowable powder, appropriate capsule size, and precise machinery.
1. Understanding Gelatin Capsules
What Are Gelatin Capsules?
Gelatin capsules are hard-shelled containers made primarily from animal-derived gelatin. They're tasteless, colorless or dyed, and dissolve quickly in the stomach. They’re widely used to encapsulate powdered, granulated, or pellet-based substances.
Gelatin capsules can actually be divided into two categories, hard gelatin capsules and soft gelatin capsules. Soft gelatin capsules are more suitable for liquids, while hard gelatin capsules are more suitable for powders and granules.
Common Capsule Sizes & Filling Capacity
Size Volume (ml) Approx. Fill (mg) Typical Use
000 1.37 800–1000 mg Large dose powders, sports supplements
00 0.95 600–800 mg Most common for herbal formulas
0 0.68 400–600 mg Nutraceuticals, light actives
1 0.50 300–500 mg Compact dose with good swallowing comfort
2 0.37 250–350 mg Pediatric or low-dose supplements
3 0.30 200–300 mg Sensitive actives, animal use
4 0.21 120–180 mg Very low-dose APIs
5 0.13 60–100 mg Micro-dosing, lab applications
2. Preparing the Powder
Use a powder mixer or granulator to blend ingredients evenly. The success of capsule filling begins with proper powder preparation.
Key Factors:
- Particle size should be uniform to ensure consistent filling.
- Flowability is critical. Poor flow leads to inconsistent dosing.
- Dryness must be maintained; moisture causes clumping.
3. Manual Capsule Filling
Manual filling is ideal for small-scale production, clinical trials, or personal formulations.
Required Tools:
- Empty gelatin capsules
- Powder blend
- Manual capsule filling tray (plastic or stainless steel)
- Powder scraper or card
- Tamper tool
- Gloves & face mask (for hygiene)
Filling Steps:
- Separate capsules into caps and bodies.
- Load capsule bodies into the filling tray holes.
- Spread powder across the tray evenly using a scraper.
- Tamp the powder down using the tamper to increase fill weight.
- Repeat powder filling until the capsule is full.
- Place capsule caps and press to close securely.
- Remove filled capsules and inspect for sealing.
Advantages:
- Low cost
- No electricity needed
- Great for startups or R&D
Limitations:
- Labor-intensive
- Low productivity (~500–1000 capsules/hour)
- Difficult to achieve consistent weight
4. Automatic Capsule Filling Machines
For medium to high-volume production, automatic machines are essential for speed, accuracy, and GMP compliance.
Types:
- Semi-automatic machines: Require manual capsule loading/separation
- Fully automatic machines: Complete operation from start to finish
NJP Series by LTPM CHINA
LTPM CHINA offers advanced NJP Series automatic capsule fillers capable of handling a wide range of powder formulations with high precision.
How It Works:
- Capsule separation using vacuum suction
- Powder dosing via tamping mechanism or dosator
- Capsule closing
- Capsule ejection
- Optional: Rejection station for faulty capsules
Top Models:
Model Output Capacity Features
NJP-400 ~24,000 caps/hr Compact, ideal for small batches
NJP-1200 ~72,000 caps/hr High-speed, PLC control
NJP-2600 ~156,000 caps/hr Multi-station, large-scale factories
5. Key Features of Automatic Capsule Fillers
- Precision dosage system with 5-stage tamping for accuracy
- Capsule orientation and vacuum separation
- Dust collection and anti-static devices
- Touchscreen PLC controls with memory recall
- Modular design for quick mold change
- Material contact parts made of 316L stainless steel
6. GMP Compliance and Hygiene Control
- GMP (Good Manufacturing Practice) requires:
- Easy-to-clean surfaces (polished stainless steel)
- Sanitization of all product-contact parts
- HEPA filtration in filling areas
- Logbooks and SOPs for maintenance and calibration
- All LTPM CHINA capsule fillers comply with EU and FDA GMP standards.
7. Common Challenges and Troubleshooting
Capsule Not Separating Properly
- Cause: Weak vacuum suction or deformed capsules
- Solution: Clean vacuum system; inspect capsule size accuracy and quality
Powder Leaking from Capsules
- Cause: Overfilling, poor capsule fit, or static powder
- Solution: Adjust fill volume; use anti-static device or dust collector
Uneven Fill Weights
- Cause: Poor powder flow, inconsistent tamping
- Solution: Use flow enhancers; calibrate tamping pins; check powder density
Capsules Not Locking
- Cause: Improper alignment or machine timing off
- Solution: Re-align cap placement mechanism; inspect springs and mold guide
Frequent Blockage of Capsule Delivery
- Cause: Humid environment, sticky powder, or worn capsule bushings
- Solution: Dehumidify area, change to free-flowing powder, replace worn parts
High Reject Rate
- Cause: Mismatched capsule sizes or improper settings
- Solution: Ensure capsule type matches mold; verify machine parameters
Regular maintenance, using consistent-quality capsules, and precise calibration can prevent 90% of these issues.
8. Maintenance and Machine Care
Daily Maintenance:
- Clean powder hopper, tamping system, and mold plates
- Check air filters and vacuum lines
- Lubricate moving parts
Weekly Checks:
- Inspect cams, guides, and bearings
- Clean electrical cabinet filters
- Test emergency stop function
Spare Parts to Keep On Hand:
- Seals and gaskets
- Vacuum cups
- Tamping pins
- Filling nozzles
- PLC touchscreen (optional)
LTPM CHINA provides full technical support, spare parts supply, and remote diagnostics.
9. Improving Efficiency and Accuracy
Tips:
- Use granulated or pre-processed powders for better fill consistency
- Match capsule size to target dose and powder density
- Choose machines with multi-nozzle tamping stations
- Integrate with:
- Powder mixers
- Vacuum loaders
- Blister packaging lines
A turnkey solution maximizes output and minimizes human error.
10. Choosing the Right Equipment for Your Factory
Checklist:
- Daily capsule output required
- Capsule size compatibility
- Product type (powder, pellets, combo)
- Available floor space
- Compliance requirements (GMP, CE, ISO)
Custom Machine Layouts:
LTPM CHINA offers:
- Factory layout design
- Customized capsule fillers
- End-to-end capsule production lines
Related Questions and Answers (Enhanced)
1. Can gelatin capsules hold pellets or microbeads?
Yes. Hard gelatin capsules are highly versatile and can hold powders, microbeads, or pellets, sometimes even in combination. With the correct dosing system (tamping pin or dosator), machines like the NJP series can handle different materials.
2. How should I store empty capsules?
Store capsules in a temperature-controlled (15–25°C) and low-humidity (<60%) environment in sealed containers. Keep them away from direct light and moisture to avoid deformation or brittleness.
3. What other machines are used in a capsule line?
A complete capsule production line may include:
- Powder mixer/blender (for uniform distribution)
- Vacuum loader (automated feeding)
- Capsule polisher (for removing dust from capsules)
- Capsule counter and bottler
- Blister packaging machine for retail packing
4. Do I need certification for my capsule filling machine?
Yes. Regulatory compliance is essential. Machines from LTPM CHINA come with:
- CE Certification (for European markets)
- GMP-compliant design (EU/FDA standards)
- ISO 9001:2015 manufacturing certification
Summary
Whether you’re just getting started or looking to scale capsule production, understanding the entire capsule filling process—from powder selection to final packaging—is key.
Manual filling works for low-volume needs, while automatic machines like LTPM CHINA’s NJP series offer unmatched speed, accuracy, and GMP compliance.
Need expert advice or a turnkey capsule filling solution?
Contact LTPM CHINA today to get a tailored recommendation and machine quote.
We provide 5-year warranty, CE/GMP-compliant designs, and full customization.