Issue link: https://www.e-digitaleditions.com/i/398011
T 30 October 2014 Tablets & Capsules test & inspection Options for leak-testing blister packages Philip Stevenson Sepha Concerns about waste, human error, and cGMP compliance are leading some packaging facilities to seek alternatives to the standard blue-dye leak test for blister packaging. he blue-dye test—or methylene blue dye ingress leak test—is the most common method for testing the integrity of pharmaceutical blister packages. It's been around for decades and the equipment required—essen- tially a vat, some colored water, a vacuum pump, and a timer—is inexpensive and easy to use. But there are sev- eral newer methods available that have advantages over the simple "dunk-and-bubble" test, including greater qual- ity assurance; accurate, objective, quantifiable test results; compliance with 21 CFR Part 11 and other cGMP stan- dards [1]; and less waste. This article compares the bene- fits and limitations of six of these alternative leak-testing methods (Table 1). The blue-dye blues The blue-dye test has two key disadvantages: It destroys the package and its results are subjective. It's destructive of packages whether they pass or fail the test, and that waste can add up. For example, a packaging line producing $1 blisters, running 24 hours a day would waste $3,360 per week, based on a testing rate of 20 packs per hour. The blue-dye test is subjective because it requires the operator to spot the bubbles that appear on defective blis- ters and to determine if there is dye present in the pack, introducing the potential for human error. To complicate this, the test is wet, messy, and difficult to validate— hardly conducive to cGMP conditions. Further more, there is no definitive, industry-accepted protocol for the test, so the amount of negative pressure (vacuum) and the length of time it's applied vary from site to site. These factors, as well as the difficulty of generating reliable batch data, have led many companies to re-evaluate the test and seek a modern, objective, non-destructive alternative. Gas analyzers Other methods include gas analyzers, often referred to as trace gas tests, known in the vernacular as the "bomb test" and the "sniffer test." These tests, like the blue-dye test, are destructive.