RT Journal Article
SR Electronic
T1 Method Comparison Study—One Step Forward toward Robust Silicone Layer Thickness Measurements
JF PDA Journal of Pharmaceutical Science and Technology
JO PDA J Pharm Sci Technol
FD Parenteral Drug Association (PDA)
SP 474
OP 489
DO 10.5731/pdajpst.2020.012567
VO 75
IS 6
A1 Lotfi, Safia
A1 Montagner, Fabio
A1 Proff, Christian
A1 Dreher, Sascha
A1 Grauschopf, Ulla
A1 Zorzi, Chiara De
A1 Pinato, Odra
A1 Panighello, Serena
A1 Funke, Stefanie
YR 2021
UL http://journal.pda.org/content/75/6/474.abstract
AB In the past decades, the silicone layer thickness and its distribution on the inner glass barrels of prefilled syringes have been characterized in several studies. However, the limited number of adequate methods to characterize thin baked-on silicone layers and the destructive nature of some analytical techniques suggest challenges to the inter-lab reproducibility of some methods. In this study, the measured silicone layer thickness of baked-on siliconized syringes was compared between two laboratories, both equipped with white light reflectometry coupled to laser interferometry instrumentation (Bouncer, LE UT 1.0, LE UT 2.0). The quantity of silicone oil of a subset of those syringes was measured by Fourier transform infrared spectroscopy. Glide force tests were realized as complementary measurements on both syringes analyzed by white light reflectometry coupled to laser interferometry instrumentation and on non-analyzed identical syringes from the same lot. Silicone profiles of all prefilled syringes including the limit of detection results replaced with 20 nm were comparable, but values were slightly lower when measured with the Bouncer instrument. An increase of the layer thickness from the finger flange to the needle side was found for all syringes with all instruments (20 nm to 130–140 nm). Glide force results were similar except for a difference in peak width in the break loose region between the laboratories. The mean quantities of silicone oil found by both laboratories were similar (64 µg/syringe and 69 µg/syringe). Overall, comparable results between laboratories suggest a good reproducibility of the thickness measurement method as a result of thorough method understanding and defining key method parameters. Hence this study presents a robust inter-lab comparison between silicone layer thickness measurements that has been a lack in the literature up to now.