Abstract
Combination products have become popular formats for the delivery of parenteral medications. Bake-on siliconization of glass syringes or cartridges allows good piston break-loose and gliding during injection at low silicone levels. Although widely implemented in industry, still little is known and published on the effect of the bake-on process on the silicone level, layer thickness and chemical composition. In this study, cartridges were bake-on siliconized in a heat-tunnel by varying both temperature from 200 to 350 degrees C for 12 min and time from 5 min to 3 h at 316 degrees C. Furthermore, a heat-oven with air-exchange was established as an experimental model. Heat treatment led to a time- and temperature-dependent decrease in the silicone level and layer thickness. After 1 h at 316 degrees C lubrication was insufficient. The silicone levels substantially decreased between 250 and 316 degrees C after 12 min. After bake-on, the peak molecular weight of the silicone remained unchanged while fractions below 5000 g/mol were removed at 316 and 350 degrees C. Cyclic low molecular weight siloxanes below 500 g/mol were volatilized under all conditions. Despite most of the baked-on silicone was solvent-extractable, contact angle analysis indicated a strong binding of a remaining, thin silicone film to the glass surface. (C) 2016 Elsevier B.V. All rights reserved.
Item Type: | Journal article |
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Faculties: | Chemistry and Pharmacy > Department of Pharmacy |
Subjects: | 500 Science > 540 Chemistry |
ISSN: | 0939-6411 |
Language: | English |
Item ID: | 48296 |
Date Deposited: | 27. Apr 2018, 08:15 |
Last Modified: | 04. Nov 2020, 13:25 |