static-free and flat

Refer to WHO GMP guidance for label legibility and permanence standards.

Explore the full topic: Equipment Troubleshooting

3. Barcode Misalignment and Vision Rejection

Modern pharmaceutical labels use 2D barcodes and serialized QR codes. Even slight misalignment leads to scanner failures.

Root Causes:

• Improper alignment of label rolls or cartons on conveyor
• Worn-out label applicator gears or feeder rollers
• Vision camera lens covered with dust or ink mist
• Inconsistent conveyor belt speed

Solutions:

• Install mechanical guides to hold label path constant
• Regularly inspect and replace worn applicator parts
• Clean lens of OCR/OCV systems before every batch
• Sync camera trigger with machine encoder for timing precision

Ensure that serialization compliance aligns with regulatory requirements under USFDA DSCSA or EU FMD.

4. Printer Calibration and Serialization Issues

Serialization printers (TIJ, CIJ, laser) must print scannable, unique codes for each pack, integrated with central databases.

Challenges:

• Wrong date/time settings on printer software
• Non-sync with MES/serialization server
• Disconnection of scanner to repository
• Ghost prints or half codes due to buffer overflow

How to Fix:

• Calibrate printers weekly; validate print quality per batch
• Backup and monitor serialization server connectivity
• Check reject bin capacity and false accept count
• Use pharma-grade printers with print confirmation features

Review serialization validation protocols and CFR Part 11 compliance during printer qualification.

5. Case Study: Barcode Rejection during Carton Printing

During a third-party audit, a batch of tablets failed barcode readability checks. Investigation revealed a deviation due to:

• Vision system misaligned post-preventive maintenance
• Operator skipped OCV verification on batch start
• No SOP for camera position revalidation post-cleaning

CAPA involved updating SOP templates, retraining line operators, and adding startup verification checklist for all vision systems.

6. Preventive Measures and Maintenance Practices

Daily Tasks:

• Clean printheads and verify print sample during line clearance
• Calibrate OCR/OCV systems and perform dummy rejection test
• Check printer ribbon/ink level and supply continuity

Weekly Tasks:

• Check print height, alignment, and drying pattern on various carton SKUs
• Synchronize labeling speed with conveyor throughput
• Lubricate moving label applicator arms

Monthly:

• Audit printer-serialization integration and trail logs
• Review deviations or print complaints logged in BMR/BPR

7. Regulatory Expectations

USFDA and CDSCO require legible, permanent, and accurate labeling under 21 CFR 211.122. Errors must be traceable via audit trails and reconciliation must be documented.

Key requirements:

• Label issuance logbook and reconciliation procedure
• Line clearance and rejection handling SOPs
• Cross-verification between printed code and batch record

8. Conclusion

Labeling and printing machine issues, if unchecked, can lead to compliance failures and product recalls. Root causes include misaligned printheads, poor-quality ribbons, camera vision faults, and misconfigured serialization settings. Pharma facilities must enforce daily checks, preventive maintenance, and real-time printer calibration. Regulatory compliance demands traceability, uniqueness, and legibility across all packaging levels—cartons, blisters, and shippers. Proper training, validated SOPs, and equipment qualification ensure trouble-free operation and accurate packaging throughout the batch lifecycle.