A Swiss pharmaceutical and fine chemicals company has invested in an automated measurement system from Mettler Toledo to meet its tight specifications when measuring density.
Cilag is part of Johnson and Johnson and has recently expanded its activities.
Among other things, the company produces cartridges for a sterilisation system, which is used by medical professionals for low-temperature instrument and medical material sterilisation.
It uses hydrogen peroxide vapour and low-temperature plasma and is particularly suited to heat-sensitive and moisture-sensitive instruments.
For this process, hydrogen peroxide has to be accurately dispensed from plastic ampoules.
Cilag manufactures these ampoules and, as part of final quality control, has to determine hydrogen peroxide concentration as well as the ampoules' filling volume.
Both processes involve measuring density.
Hydrogen peroxide concentration can be derived from density measurement while density and fill weight serve to calculate fill volume.
Density measurement is therefore key to the quality control of sterilisation ampoules.
'We have very tight specifications and therefore needed a highly accurate density instrument,' says Mr Satzinger, quality control manager at Cilag.
'We previously experienced problems meeting these specifications with a manual, stand-alone instrument as hydrogen peroxide tends to degas and form bubbles when filling the cell with a syringe,' he added.
To overcome these challenges, Cilag chose an automated density measurement system from Mettler Toledo: the DE51- SC30 combination.
Now, it is only necessary to open the plastic ampoule and place it in a sample vial on the sample changer.
The instrument does everything else.
It returns the sample to the ampoule after each test, which is particularly helpful if the sample needs to be remeasured.
'The standardised filling, cleaning and drying sequence helps to avoid errors due to gas bubbles and ensures that every sample is treated exactly the same,' said Satzinger.
'We only analyse six samples per day,' he added, referring to the workload of the system, indicating that reasons other than productivity improvement were important when the automated system was selected for the analysis of hydrogen peroxide concentration in a sterilisation product.
With tight specifications and multiple operators using the equipment, automation ensures that results are always reliable.
Cilag had another reason to opt for an automated system.
The hydrogen peroxide in sterilisation ampoules is very concentrated.
It can be dangerous when in contact with skin and particularly with eyes.
'Thanks to the automated system, manual interaction with the product has stopped almost completely,' said Satzinger.
