Common problems with capsule filling machines

How to troubleshoot and avoid costly downtime in pharmaceutical production

Capsule filling machines are the backbone of solid dosage production, handling thousands of capsules per hour with precision. Yet industry data shows that 78% of pharmaceutical manufacturers face unplanned downtime due to equipment issues annually, with Europe and U.S. firms losing millions of dollars yearly to machine failures and product rejects . Understanding common problems and their solutions is critical for maintaining compliance and efficiency. Below are the most prevalent issues and expert troubleshooting tips.

1. Capsule jamming and orientation failures

Symptoms: Capsules get stuck in feeding systems, show improper orientation (over 3% inverted), or fail to align with filling mechanisms .

Root causes:

• Substandard capsule shells with size variations or surface defects

• Misaligned guide rails, loose reed screws, or faulty vibrators

• Overloaded hoppers or excessive environmental dust

Solutions:

• Replace with qualified capsules matching machine specifications

• Tighten loose components and adjust vibration voltage for optimal capsule flow

• Clean feeding systems daily and maintain 40-60% humidity in production areas

2. Inconsistent fill weights and powder bridging

Symptoms: Underfilled/overfilled capsules, empty shells, or weight deviations exceeding pharmaceutical standards .

Root causes:

• Poor powder rheology (flowability, density, or compressibility issues)

• Worn dosing disks or clogged filling rods

• Mismatched capsule and formulation (e.g., hygroscopic powders with gelatin shells)

Solutions:

• Conduct pre-formulation analysis: Measure angle of repose for flowability and add glidants if needed

• Calibrate dosing systems daily and replace worn parts every 5,000 operating hours

• Use HPMC capsules for moisture-sensitive formulations instead of gelatin

3. Improper capsule closure and leakage

Symptoms: Seam gaps, powder leakage, or incomplete locking leading to shelf-life reduction .

Root causes:

• Capsule body-cap mismatch or soft shell material

• Worn (sealing molds) or misaligned tooling

Solutions:

• Source capsules from certified suppliers with consistent dimensional tolerance

• Inspect and replace sealing molds quarterly; realign tooling after maintenance

4. Equipment instability and mechanical errors

Symptoms: Excessive vibration, loud noises, or sudden speed fluctuations .

Root causes:

• Unsecured installation or loose drive belts/gears

• Overheated motors or blocked (heat sinks)

• Stuck pressure springs in mold tracks

Solutions:

• Reanchor machines and tighten (transmission components) monthly

• Clean motor heat sinks weekly and schedule 2-hour cool-down periods after 8 hours of operation

5. Control system malfunctions

Symptoms: Touchscreen unresponsiveness, program crashes, or parameter drift .

Root causes:

• Electromagnetic interference or power fluctuations

• Outdated software or damaged controllers

Solutions:

• Install voltage stabilizers and electromagnetic filters

• Update system software quarterly and backup parameters daily

Proactive prevention strategies

1. Scheduled maintenance: Create a checklist for daily cleaning, weekly part inspections, and quarterly replacement of (wear parts) .

2. Operator training: Ensure staff understand powder properties and machine calibration (e.g., adjusting filling levers for powder variations) .

3. Quality control: Test capsule strength and powder flowability before production runs .

“Most machine failures stem from (ignoring details) like powder characteristics or minor part wear,” says a senior engineer at Richpacking. “A proactive approach can reduce downtime by 60%.”

For personalized troubleshooting, contact our technical team or download our free Capsule Filling Machine Maintenance Checklist.