Woman doing visual quality checks on pharmaceutical vials

Glass delamination under full control


SCHOTT Pharma: Your reliable solution provider for delamination control

Borosilicate Glass has proven to be the most reliable material for storing injectable drugs. However very rare, glass delamination poses a risk for patient safety, having caused recalls of injectable drug products over the past several years.

There is no single factor that causes glass delamination in a pharmaceutical setting, and it can be a difficult problem to address because it typically doesn’t show up until the product has been stored in the container for several months. Nevertheless, there are concrete steps that pharma companies can take to minimize the risk of delamination.

The Challenge

Glass delamination - a rare phenomenon hard to predict

The standard glass converting process can lead to an altered surface area, the “heel zone”:

This area might be less chemically durable and therefore in general more susceptible to delamination. Delamination means the appearance of visible glass-like flakes in the drug solution after storage for a certain time period. Two different mechanisms are behind.

Delamination is not easy to predict and a phenomenon due to very rare outliers during the vial production process. Many different factors exist that influence delamination, e.g. kind of post-treatments, the drug substance and –formulation, pH, storage conditions and many more. It is key to perform predictive screening studies in advance. With their expertise in that field, SCHOTT Pharma Services can be of great help.

Glass delamination is a significant problem for the pharmaceutical industry
The Solution

Glass delamination under full control with SCHOTT EVERIC® pure vials

If predictive screening studies indicate a risk for delamination, EVERIC® pure is SCHOTT’s answer. Thanks to a leachable-improved glass tubing (FIOLAX® CHR: glass composition unchanged) and a patented hot-forming technology, SCHOTT Pharma manages to eliminate the production outliers with this changed heel zone. Without an additional coating or treatment, SCHOTT Pharma tackles the origin of the phenomenon by producing a vial with a homogenous inner surface.

The SCHOTT Quicktest (a dedicated, statistical in-production release test with defined limit values) controls that EVERIC® pure vials meet their specifications with regard to low leachables and delamination under full control. The continuously increasing demand and the trust of our customers are proof that EVERIC® pure vials are established as the gold standard against delamination.

Everic pure glass vial to get glass delamination under control
Safer Pharmaceutical Packaging with SCHOTT’s Glass Delamination Technology

Frequently asked questions about glass delamination

Delamination is defined as the peeling of inorganic flakes from the inner glass surface of a pharmaceutical vial as a result of interaction with its contents.
Many factors influence delamination, for example the kind of post-treatments, the drug substance and formulation, storage conditions and the vial manufacturing process. For the standard manufacturing process during the bottom forming of the vial volatile components diffuse back into the wall near bottom area (heel zone) generating a microzone with reduced chemical durability. This microzone is the starting point for glass delamination. A more tightly controlled bottom forming together with a special release criteria (Quicktest) as done for EVERIC® pure is able to avoid the formation of microzones in the wall near bottom area fully. Today, EVERIC® pure is well established for formulations which are terminally sterilized as diluents and water for injection and for phosphate buffer based formulations. EVERIC® pure is more and more considered as alternative for ammonium sulfate treated containers.
  • Glass delamination in vials is a rare phenomenon and not easy to predict as there is no single factor that causes glass delamination. SCHOTT Pharma therefore offers predictive glass delamination screening studies based on USP <1660> to be performed prior to commercialization.
  • The test procedure combines different analytical techniques as SEM cross-section analysis, stereomicroscopy, optical inspection of particles, ICP-MS, EDS and SIMS.

Glass Flakes: Pre-Testing stops a big problem before it even starts

This article outlines why glass delamination occurs and, more importantly, how pharma companies can use accelerated testing to pick the right containers for their drug products and avoid costly recalls.

Glass Flakes Pre-Testing stops a big problem before it even starts

Get in touch

Diana Löber

Diana Löber

Global Product Manager Vials

*Field is required

SCHOTT Pharma will use your data only for reacting to your inquiry. Find more information about processing your personal data in SCHOTT Pharma’s data privacy policy


I agree that SCHOTT Pharma AG & Co. KGaA may send me e-mails with information on products and services of SCHOTT Pharma. My data will not be passed on to third parties. After registration, I can revoke my consent at any time at the SCHOTT Subscription Center following the link in each email footer.