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 due to specific and localized corrosion of glass vials, is a rare but very serious problems, and the FDA (U.S. Food and Drug Administration) put a warning to the pharma industry in 2011. Technical Committee 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 Technical Committee. Five types of vials with different expected delamination propensity were tested using a protocol which includes autoclaving at 121 °C of vials filled with a NaCl solution adjusted to pH 8 with NaOH solution, a coloration test, and ICP-OES determination of Si, B and Al. Although no flake formation was observed, the results shown that the combination of strong coloration at the bottom of 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 vials with respect to the propensity to corrosion. With respect to 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 ratio.