Delamination has existed as a fundamental glass challenge for pharmaceutical manufacturers for decades.
While boron, a volatile element, is the root cause for delamination – the converting process also impacts a container’s chemical durability. During the converting process, specifically the step where the glass cane is parted (or separated) into two containers, the flame releases the boron from the glass network. Boron-containing compounds move around and evaporate as gas out of the glass network largely in the heel region of the vial.Like a charged helium balloon sticks to a wall or object, the boron particles adhere to cool regions in the side-walls and heel (bottom) of the vial. A composition already rich in boron is now converted into its final format, with deposits that are richer in boron and sodium than the intended composition. This alters the glass chemistry of the container’s drug-contact surface. These areas rich in sodium borate, are vulnerable to delamination and ultimately pose risk to pharmaceutical product quality.
There are four steps from the formation of a heterogeneity to delamination. Corning notes those steps include, 1) Formation of heterogeneity, 2) Leaching, 3) Swelling and 4) Spalling off a delaminated flake.
Because Valor Glass has uniform surface chemistry and does not form boron-rich heterogeneities during converting, it will not delaminate.
A Step-Change in Innovation
Corning Valor® Glass is a boron-free glass packaged designed specifically for pharmaceutical use to eliminate delamination. Corning was able to maintain a glass network comprised of elements used in borosilicate vials, including silica and alumina while eliminating delamination. Valor Glass is converted using traditional processes.In addition, Valor Glass offers improved overall extractable and leachable performance for parenteral packaging applications relative to comparable borosilicate containers. This means manufacturers see lower overall concentrations or quantities of elements extracting out of Valor Glass’ composition relative to borosilicate containers, reducing the risk of potential interactions between the container and the drug product, even for low-fill conditions.