The Challenge
A Schedule M-licensed oral liquid formulation plant in Hyderabad runs four labelling lines producing cough syrups, antacid suspensions, and paediatric nutritional supplements — all exported to regulated markets in South-East Asia, Africa, and the Middle East. Labelling compliance is a critical GMP requirement: each SKU must carry the correct label, correctly oriented, without damage — and label records must be reconciled at batch close. The consequences of a mislabelled batch reaching the market range from import detention to product recall and, in the case of paediatric formulations, potential patient harm.
The plant experienced two labelling incidents in a 16-month period. In the first, a partial batch of 1,800 bottles had labels applied upside-down due to a reel loading error — the batch was quarantined and relabelled at a cost of ₹4.2 lakh. In the second — more serious — a wrong label reel was loaded at a line changeover, and 320 bottles of a paediatric product were partially labelled with an adult dosage label before the supervisor caught the error. The batch was destroyed.
The plant's regulatory affairs team flagged both incidents to the quality council as "near-misses with patient safety implications." The plant quality head needed a system that detected 100% of label defects — including wrong labels — at full line speed, with a rejection mechanism reliable enough to prevent any defective bottle reaching the carton-packing station.
The Solution
Optomech installed the LIS (Label Inspection System) on all four labelling lines, rated at 14,000 bottles per hour — above the plant's peak throughput of 11,200 bph. The LIS uses high-speed industrial cameras to capture the full label face on every bottle in motion and inspects for label presence, orientation (upside-down detection), vertical and horizontal alignment, tilt, fold, truncation, and wrong label identity via SKU reference image matching.
The wrong-label detection capability was configured to address the plant's specific changeover risk: the LIS stores reference label images for each of the plant's SKUs in a recipe library. At line changeover, the operator selects the new product recipe on the touchscreen. If a label from a different SKU appears on the line, the bottle is rejected and an alert fires at the supervisor console. Critically, the first wrong label in any run triggers a line hold alarm — requiring supervisor acknowledgement before production can resume. This directly addresses the "run-ahead" scenario that caused the paediatric labelling incident.
Each rejection is logged with image, defect type, timestamp, batch number, and line ID. Batch-level label reconciliation reports are auto-generated at batch close — matching labels issued to labels applied, with full rejection audit trail — directly supporting the batch manufacturing record (BMR) as required by Schedule M and WHO-GMP standards.
Defects Detected by the System
Results Achieved
| Metric | Result |
|---|---|
| Mislabelling incidents | Zero mislabelling events in 18 months since LIS installation |
| Wrong-label events detected | 6 changeover loading errors detected and halted in first year — before any bottles passed |
| Upside-down labels caught | Avg. 38 upside-down / misaligned labels per shift per line — all auto-rejected |
| Throughput | All lines running at full speed — no reduction in labelling output |
| BMR reconciliation | Auto-generated label reconciliation reports accepted in WHO-GMP audit |
| Near-miss events | 0 patient safety near-misses in 18 months (vs. 2 in prior 16 months) |
| Batch destruction cost | ₹4.2L relabelling + batch destruction costs: ₹0 in post-LIS period |
| Regulatory audit outcome | WHO-GMP renewal — labelling control cited as best practice by inspector |
"Before the LIS, our labelling incidents were the quality council's biggest concern. After installation, the system caught six wrong-label reel loads in the first year — all stopped before a single bottle reached packing. The WHO auditor specifically commented on our labelling control system during the GMP renewal. That comment went into our quality manual as a reference standard."— Head of Quality Assurance, Oral Liquid Formulation Plant, Hyderabad
Labelling compliance risk on your packaging line?
Wrong label detection, upside-down rejection, auto-BMR reconciliation — all at full line speed. Share your labelling challenge and we'll propose the right LIS configuration.