Checking Seal Integrity

Seal integrity is crucial. A good seal ensures “product efficacy, shelf-life stability, and microbial sterility,” says Jeff Morrow-Lucas, director of Engineering at Leak Detection Associates. Non-destructive leak detection technologies include vacuum decay, airborne ultrasound, helium trace, high voltage, and laser-based headspace analysis. Selecting the right technology depends on the product, package, and sensitivity requirements. Morrow-Lucas notes it’s important to understand what the equipment is protecting against and advises verifying that desired pass/fail limits can be delivered by the model chosen. He also recommends selecting flexible equipment that works across today’s and tomorrow’s packaging formats. 

Recent equipment innovations in seal integrity testing include PTI’s updated VeriPac tester, a vacuum-based unit that combines the ability to locate smaller leaks and shorten test cycle time with several in-demand features, such as non-subjective results, qualitative data analytics, and data trending. FLEX test chambers accommodate multiple flexible package sizes (1).

Another recent introduction from PTI, the semi-automatic Seal-Scan airborne ultrasound tester, delivers an in-depth profile of seal quality and works with any material combination regardless of color, transparency, print, surface finish, or porosity (2). For online applications, the Seal-Sensor airborne ultrasound tester identifies seal defects in less than one second and locates flaws that a human inspector cannot see. The unit passes or fails each pouch and also captures quantitative, traceable data (3). 

Lighthouse Instruments supplies laser-based headspace analysis technology for the KHS Series inspection system from Bosch. It performs 100% container/closure integrity (CCI) inspection on vials, cartridges, and ampules and detects leaks by identifying changes in headspace gas composition or total headspace pressure. The company also offers FMS benchtop test systems as well as the Pulsar Headspace CCI Inspection Lease System for online applications (4).

CMP PHARM.MA combines high-voltage leak detection with visual inspection and labeling in its RS1-LAB/RS2-LAB machines, capable of handling 200 or 400 ampules, vials, or cartridges/min, respectively. Machines are equipped with four leak-test stations and a rotation system to support 360-degree surface inspection. Systems check for particles, correct fill level, leaks, and other flaws (5).

Although X-ray inspection typically checks for product contaminants, the Integrity-Checktoolsbuilt into the Safeline X34 system from Mettler Toledo can identify products trapped in the seal of a blister pack or other format (6). “Historically, vision systems were utilized to perform this inspection,” says Sarrina Crowley, marketing communications manager at Mettler Toledo, North America, Product Inspection. However opaque packaging can be challenging for vision technology. Because opacity doesn’t affect X-ray performance, it “can detect product in seals in most scenarios,” she reports. 

For induction seals on containers, cooled thermal imaging technology can check seal quality through the closed cap. The Countec Coglix InspecSeal TI-200 machine, represented in North America by Key International, inspects for damaged, inverted, incomplete, or missing seals; over- or under-heating; and loose or crooked caps and generates real-time data and statistics. The system is compatible with glass or high-density polyethylene (HDPE) containers from 20–200 mm in diameter and 50–300 mm in height and HDPE, polypropylene, or child-resistant caps (7).

References

1. PTI-Package Technology & Inspection, “Transformative Shifts in Vacuum Decay Leak Testing,” Brochure, October 2018. 

2. PTI-Package Technology & Inspection, “Seal Quality Testing and Seal Analysis,” Brochure, 2019. 

3. PTI-Package Technology & Inspection, “Immediate Seal Check and Seal Verification,” Brochure, 2018. 

4. Lighthouse Instruments, “Bosch KHS for CCI,” www.lighthouseinstruments.com/lighthouse-instruments-bosch-khs-series, accessed May 28, 2019. 

5. CMP Pharm.Ma, “CMP Pharma Inspection,” Brochure, 2018. 

6. Mettler Toledo Product Inspection, “Mettler Toledo’s New Safeline X34 X-ray Inspection System Quickly and Reliably Performs Component Presence Verification and Contamination Inspection in Pharmaceutical Products,” Press Release, March 25, 2019. 

7. Coglix Co., “InspectSeal Sealing Inspection System,” Brochure, undated.