Product integrity issues in the global pharma market are a hot topic at the moment and many companies are reviewing and increasing their quality control procedures. Good leak detection procedures are a critical element of cGMP and provide the manufacturer with confidence over the integrity of their packs, as well as ensuring product stability and overall shelf life.

In our experience, leaks in pharmaceutical packaging are relatively uncommon on a well set‑up and maintained pharmaceutical line. Assuming that the material itself is correctly specified, installed and not out of date, when a leak does occur it tends to be the result of problems with packing machine setup or material issues. Common problems include incorrectly set seal temperatures/pressures or when lidding material is incorrectly tensioned; both of these lead to problems in the seal area characterised by poorly defined knurling pattern or capillary channels. Similar problems can also occur if there are issues with the seal station as dies can become misaligned, worn or damaged. Leaks also occur when dust and the packaged product compromise the seal.

Less commonly, leaks may occur when packaging line tooling gets damaged or when foreign bodies, such as cleaning materials, are introduced to the line.

For leak testing, the most common method is the destructive methylene blue test. However, many pharma companies are improving their quality control systems by turning towards a new generation of non‑destructive leak detection systems that generate more accurate results and that integrate with quality systems. Such technologies include lasers, ultrasonics, gas sniffers and load cell technologies to monitor physical changes in packaging under vacuum conditions. All of these are driven by software that enables objective results to be captured without damaging the product. The capture and integration of these detailed and specific results, such as what pocket in a blister pack is leaking, for example, helps production to identify reoccurring problem areas and implement appropriate solutions. Also, by being non‑destructive, new generation testing technologies enable manufacturers to recover product that would otherwise be destroyed, which is a major cost saving. A recent installation of Sepha’s laser test machine (Blisterscan) enabled a leading global manufacturer to save more than $250 000 in product costs within 3 months of replacing blue dye testing on a single line producing a high value drug. In an era where manufacturers are striving to drive costs down, modern non‑destructive technologies are making a dramatic impact on their cost saving programmes.

As mentioned previously, new generation leak detection technologies also tend to generate more accurate results compared with traditional tests. For instance, laser‑based technologies can detect micronic holes with a high accuracy. A recent test study by Sepha showed that in a sample of blister packs laser drilled to create 10 micron holes, blue dye testing detected only 50% of the holes across the sample.¹ A modern laser scanner, however, detected 100% of the holes across the sample.

Non‑destructive technologies also offer environmental benefits, as there are many issues relating to the disposal of drugs, packaging and methylene blue dye. Most modern leak technology systems are non‑destructive, and we have seen a significant rise in enquiries from companies wanting to improve their green credentials and recover, rather than dispose of, leak‑tested product. Additionally, because of the objective data provided, manufacturers can detect faulty packs much quicker and implement production improvements that dramatically reduce packaging waste.

The changing market

The pharmaceutical packaging market is increasingly global, with a dual focus on improving efficiencies and increasing quality levels by improving package integrity, lowering production costs and lowering environmental impact. This trend is applicable to many industry players including traditional pharma manufacturers, generic manufacturers and contract packers. Consequently, manufacturers of leak detection technology are being challenged by the pharma industry to provide:

• products that are flexible across a range of production lines and package types
• products that increase the accuracy and objectivity of testing
• products that enable valuable drugs to be recovered rather than destroyed
• products that have software that will integrate into their quality control systems.