Glass delamination, which involves flakes of glass peeling off of the inner surface of a vial as a result of interaction with a pharmaceutical formula, is a significant concern. SCHOTT has introduced a new line of vials, SCHOTT Vials DC, made with an improved manufacturing method, the company announced in a press release at the American Association of Pharmaceutical Scientists (AAPS) Annual Meeting and Exposition. The vials are produced with an optimized process to have a more homogeneous surface and high chemical stability and tested with SCHOTT Delamination Quicktest, a patented test method that documents a container’s tendency toward delamination. SCHOTT Vials DC will be available as 2R to 10R ISO vials at the beginning of 2014.
“When the bottom of the vial is formed, volatile components like boron and sodium evaporate,” said Gerry Wilkins, director of sales for SCHOTT North America, in the press release. “They then go on to form inhomogeneous spots on the glass surface near the bottom of the vial that show a higher tendency to delaminate. With our new SCHOTT Vials DC, we have advanced the production process to ensure that the glass surface is more homogeneous and thus less susceptible to delamination.”
To confirm this effect, SCHOTT conducted storage studies with systems that showed a high tendency toward delamination while using standard Type I vials. The results showed that SCHOTT Vials DC remained stable even after six weeks of storage involving a 15% potassium chloride solution and a 10% sodium thiosulfate solution at a temperature of 60 °C, although conventionally manufactured vials showed clear initial signs of delamination.
SCHOTT uses its SCHOTT Delamination Quicktest to monitor the manufacturing process to control and minimize the risk of delamination. “In the past, the vials had to be examined carefully with a stereo microscope during testing in order to comment on delamination. For this reason, it was impossible to control the production process in a timely manner,” explained Wilkins. “In the SCHOTT Delamination Quicktest, a certain number of vials are removed from every batch. The random samples are then subjected to stress for four hours inside an autoclave to tease out the delamination critical zone. In a second step, the vials are filled with high purity water (WFI-Water for Injection), and sodium is extracted inside an autoclave. The volume of sodium extracted correlates with the probability that the vials will experience delamination at a later point in time.” By monitoring these values and adhering to certain threshold values, SCHOTT is now able to control the risk of delamination.