Delamination Propensity of Glass Containers for Pharmaceutical Use: A Round Robin Activity Looking for a Predictive Test

Delamination, which is the formation of flakes in drug products owing to specific and localized corrosion of glass vials, is a rare but serious problems, on which the FDA (U.S. Food and Drug Administration) put a warning to the pharma industry in 2011. The Technical Committee (TC) TC12 of the International Commission on Glass (ICG) was created in 2012 with the aim to study the problems related to pharma packaging. The first task of TC12 was to address the problem of predicting the propensity of glass vials to delamination, leaving the study of the mechanism(s) of flake formation as a possible future activity. This paper reports on the results obtained in a round robin test, which involved all the labs of the companies represented in the TC.Five types of vials with different expected delamination propensities were tested using a protocol that includes autoclaving at 121°C of vials filled with NaCl solution adjusted to pH 8 with NaOH solution, a coloration test, and ICP-OES determination of Si, B, and Al.Although there was no flake formation, the results showed that the combination of strong coloration at the bottom of the vials and high silicon concentration in the solution is correlated to an observable morphological modification/corrosion of the inner surface of vials in the bottom region. The test protocol is therefore useful for checking the quality of the vials with respect to the propensity to corrosion. Regarding delamination, no direct correlation with the testing results could be obtained yet. The method allows catching differences in the corrosion behavior, mainly between sets of vials with comparable surface:volume.LAY ABSTRACT: The U.S. Food and Drug Administration (FDA) warned the pharma industry about glass delamination inside primary packaging containers. Delamination is a type of glass corrosion that produces glass flakes, which could seriously affect patient health.Fortunately, delamination is a very rare event. On the other hand, it is very difficult to predict its occurrence. In 2012, the International Commission on Glass (ICG) created a Technical Committee (TC) on pharma packaging-with the initial goal to study an easy and reliable test for predicting the propensity of vials to delamination-involving the most important glass vial producers and pharma companies. This paper reports on the results obtained in a round robin test on different types of vials with different expected propensities to delamination. A specific testing protocol was adopted. In none of the vials, including those with an expected high propensity, glass flakes were observed, demonstrating that delamination is a rare event. However, the test is able to predict the occurrence of morphological modification/corrosion of the inner surface of vials in the bottom region. Therefore, the testing protocol is proposed as a method to evaluate differences in the corrosion behavior mainly between sets of vials with comparable surface:volume.