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Foil pouches are commonly used when a product requires multi-layered packaging. They are utilized as the innermost layers of packaging. Since the foil pouches come into direct contact with the packaged product, they must be of the highest quality and extremely hygienic. They are typically composed of aluminum and are used to protect products from high temperatures. Furthermore, foil pouches have a low moisture vapor transfer rate. Foil pouches usually contain three to four layers. The higher the number of layers, the higher the pouch quality. Each extra layer increases the strength of the pouch.

Foil pouch integrity testing offers a unique set of challenges. The occurrence of foil punctures is an issue in most packaging techniques that use foil as the product barrier. These imperfections can occur when the foil is rolled into thin sheets and microscopic particles are rolled into the foil by mistake. Handling of the packages during the assembly of the foil and insertion of the drug product is the most typical source of the defect. Although the human eye can only reliably spot punctures bigger than 100 µm, these faults are difficult to identify. Punctures smaller than this can cause substantial ingress and, as a result, affect the effectiveness of the product.

How to Inspect Foil Pouches for Quality Control Using Helium Leak Test?

A highly sensitive method of detecting leaks in enclosed systems by using helium as a "tracer gas" is known as helium leak testing. Pre-filled syringes, foil pouches, and cold form blister cards are the most common applications of helium leak testing. Each of these package types is meant to keep out harmful environmental pollutants including debris, germs, and even gases while maintaining the sterility of the drug product inside. The leak rate is calculated from the amount of helium that escapes from the package.

The sensitivity of the helium leak detection methods makes it an ideal platform for quality control testing foil-based packaging systems. The test technique is designed to identify helium that has been trapped in the packaging system and has leaked via micro-voids in the pouch. Placing the foil pouch in the custom-designed test fixture and drawing a vacuum is the first step in a test sequence. Helium thus escapes through possible defects in the package as a result of the resultant pressure difference. The flow is directed to the analyzer cell at vacuum pressure, where the escaping helium gas is measured in the cell.

The average test cycle time is between 20 and 60 seconds. The test chamber is evacuated to the environment when the test cycle is completed and the measurement is recorded, and a new sample can be tested. The LDA HSAM helium concentration device is used to detect the helium concentration value of each pouch once all samples in the designated set have been tested. This approach normalizes the helium leak rate to 100%, allowing direct comparison of all test samples as well as the manufacturing line configuration.

Helium leak testing, one of the most commonly used CCI testing methods, is used to accurately determine the tiniest of the leaky opening in the foil pouches. Using this method, leaks can be quantified and detected with a high level of sensitivity and quality control testing. The Food and Drug Administration- FDA has long recognized helium leak detection as a consensus standard for package integrity evaluation.