WILCO - Leak Testing and Headspace Analysis Machines

WILCO provides in-line, off-line and laboratory machines with non-destructive testing methods for monitoring the oxygen content and container closure integrity either separately or combined. Our patented leak detection methods based on process analytical technologies (PAT) also offer the opportunity to monitor finishing processes.

We work closely with organisations such as the PDA and FDA, and our customers, in order to develop new leak detection technologies for the pharmaceutical sector, as well as machines operating at speeds matching today’s high-speed manufacturing environments.

Head space analyser (HSA)

By guiding a wavelength-modulated low-power laser beam (class one) through the headspace of a parenteral product, gas concentrations such as oxygen or moisture can be reliably detected using a laser absorption spectroscopy. Our rotary machines use an individual laser beam for each testing station, achieving test speeds of up to 600 vials/min.

This technology allows the smallest oxygen levels to be accurately measured and provides information as to the remaining absolute pressure in the headspace. It can also be used for monitoring container closure integrity. By allowing the vials a certain time period to change the headspace conditions, leak sizes as small as 1µm and smaller can be reliably detected.

By monitoring the moisture or oxygen in the headspace, the performance of the drying process and oxygen removal process during the lyophilisation process are indirectly monitored, allowing process improvement in order to avoid any impact on product stability.

Near infrared inspection system

The near infrared (NIR) inspection system is a quantitative method using a near infrared technology for the determination of the water content in freeze-dried products. The NIR system is capable of handling up to 3,000 vials/min.

The method used is near infrared diffuse reflection spectroscopy. The vial, which contains the pharmaceutical product, a residual material of a lyophilisation process, is exposed to a broadband light source in the range from 1,000nm to 2,200nm. The light interacts with the lyophilised product itself and reflects this portion of light, which has not been absorbed from the material.

The missing energy along the NIR wavelength range provides a specific spectral response where individual chemical and physical properties can be identified. One of the properties that can be extracted is a signal around 1,920nm, which clearly relates to a specific absorption of water molecules. Therefore, this signal scales directly to the relative water content in the lyo cake.

In terms of the freeze-drying process, which is well known for sometimes producing unidentified, out-of-spec products regarding the moisture content even under strict parameter control, this method provides a perfect tool for a final quality check.

Liquid-filled container leak detection

Our patented liquid-filled container (LFC) leak detection method measures the loss of vacuum inside a test chamber as a result of either headspace gas leakage or liquid vapourisation from a leak.

Once the containers are placed in the testing chamber, an absolute pressure below the flash point of the liquid will be created. Since the vapourisation of even a very small amount of liquid will cause a large increase in pressure in the small test chamber, the sensitivity of the LFC method is significantly greater than for standard pressure decay methods.

Our LFC technology is a suitable leak detection method for containers filled with liquid, like pre-filled syringes, liquid-filled vials or ampoules, BFS strips and BFS ampoules.

Pressure / vacuum decay leak detection methods

Pressure or vacuum decay leak detection methods, which measure the increase or decrease of a differential pressure, are selected based on the characteristics of the containers as well as on the characteristics of the product.

For hazardous products we recommend the use of a pressure decay method for leak detection purposes, so any contamination will be reduced and/or kept under control.

To achieve the high performance that our customers expect, we design the testing chambers for each type of container to optimise the air volume around the samples. These methods are suitable for vials, ampoules and pouches.

Combined leak detection methods

The versatility of our methods is demonstrated by the fact that they can be offered in a combination approach; i.e., two or more leak detection methods, HSA and/or NIR, can be installed using a single machine platform.

This flexibility allows different types of containers to be tested by selecting the corresponding change parts with only one machine.

In-line leak detection machine with force sensor technology

For flexible packaging type IV bags, our force sensor technology measures the change of the applied pressure on the bags in case of a leak. We differentiate between leak sensitivities in the head space and the liquid part.

Thanks to our experience and know-how in machine manufacturing, in 2010 we will deliver the first in-line leak detection machine using force sensor technology, which will achieve a speed of 11,000 IV bags per hour.

In combination with our vacuum decay method, we use force sensor technology for detecting leaks in blisters and pouches.