Class III medical devices have a unique combination of criteria and package features that necessitate a comprehensive approach to determining the best inspection procedures. For medical package inspection, there are a variety of methods that require a thorough understanding to assure quality.
Manual visual inspection has been the most common form of inspection for medical device packaging. While an ASTM standard (ASTM F1886) covers this concept, it may not be applicable for all applications and has limitations. Even though a 75-micron channel defect can be detected by manual visual inspection, the ASTM method F1886 indicates that the chance of detection ranges from 60% to 100%. This vast range of uncertainty does not give the level of assurance required for the packaging of high-risk medical devices.
Although certain offline leak detection techniques can offer a quantitative evaluation of seal quality, they miss some of the most prevalent seal problems seen in Class III medical device packaging. Testing peel strength or utilizing other destructive methods will not reveal random seal problems. For class III medical devices, online non-destructive inspection procedures are excellent since they provide quality control with comprehensive manufacturing lot data.
All Class III medical devices must be sterile, however, container materials and design differ widely. A non-porous pouch or tray demands an entirely different technique than a porous pouch or tray. Tyvek® offers a sterile barrier, and the porosity of the material limits the leak test procedures that may be used on the package body. When it comes to porous packaging, the focus of online inspection moves away from leak detection and toward seal quality evaluation.
Vacuum decay and Airborne ultrasound are the two main methods used by PTI/CCIT to inspect medical device packaging. Both methods are aimed at providing quantitative and deterministic test results in order to assess package quality. In terms of function and performance, the two technologies are entirely different. Package integrity and leak path detection are the main objectives of Vacuum decay. Meanwhile, Airborne ultrasound technology focuses on package seal inspection and seal quality. Both approaches aim to meet the basic requirements of being reliable and sensitive inspection procedures for Class III medical device applications.
Vacuum Decay (ASTM F2338)
Vacuum decay is the most practical and sensitive vacuum-based leak test method of CCI. When testing pouches, a versatile adjustable test chamber may be utilized to test pouches of various sizes. The package is then placed into the vacuum-sealed test chamber. The level of vacuum, as well as the change in vacuum during a pre-defined test duration, are both monitored during the short test cycle. The change in vacuum indicates the existence of leaks and defects within the package. Vacuum decay leak testing is a go-to standard for sterile products because of its sensitivity and dependability. The approach is ideal for laboratory offline testing and production applications for quality assurance process control, since test equipment may be developed for manual or automation operation.
The ASTM Vacuum decay leak test technique (F2338), which has been accepted by the FDA as a consensus standard for package integrity testing, was developed using PTI VeriPac technology. As a deterministic test technique for package integrity test solutions, Vacuum decay is mentioned in ISO 11607 and the new USP 1207 guideline document.
Airborne Ultrasound (ASTM F3004)
Airborne Ultrasound is an ASTM Test Method F3004-13 and is one of the most effective methods for non-destructive seal quality inspection of flexible packaging. It is mentioned in ISO 11607 and the new USP 1207 guidance document. Most inspection methods are challenged by the leaking nature of porous packaging, but Airborne ultrasound, with its non-destructive measure of seal quality, effectively overcomes those challenges.
The non-contact Airborne ultrasonic testing technique is used in both Seal-Scan (Offline) and Seal-Sensor (Online). Ultrasonic waves propagate through the material as a package seal passes through the sensor head, producing sound waves to be reflected. When defects are encountered, the signal intensity is reduced or eliminated. The larger the acoustic gap between mediums, the more sound is reflected and less sound is transferred through the seal.
The variety of package forms and materials makes inspecting the integrity of class III medical device packaging a challenge. CCIT's scientists and engineers have vast industry experience and can prove a complete solution, including test method development and equipment validation for Class III medical device packaging.