title: Distribution of silicone oil in prefilled glass syringes probed with optical and spectroscopic methods.
abstract: Prefilled glass syringes (PFSs) have become the most commonly used device for the delivery of recombinant protein therapeutics in parenteral formulations. In particular, auto-injectors preloaded with PFSs greatly facilitate the convenient and efficient self-administration of protein therapeutics by patients. Silicone oil is used as a lubricant in PFSs to facilitate the smooth motion of the plunger during injection. However, there have been few sophisticated analytical techniques that can qualitatively and quantitatively characterize in-situ the morphology, thickness, and distribution of silicone oil in PFSs. In this paper, we demonstrate the application of three optical techniques including confocal Raman microscopy, Schlieren optics, and thin film interference reflectometry to visualize and characterize silicone oil distribution in PFS. The results showed that a container coating process could produce unevenly distributed silicone oil on the glass barrel of PFSs. An insufficiency of the amount of silicone oil on the glass barrel of a PFS can cause stalling when the device is preloaded into an auto-injector. These analytical techniques can be applied to monitor the silicone oil distribution in PFSs.
authors.affiliation: Department of Formulation and Analytical Resources, Amgen Inc., Thousand Oaks, CA 91320, USA. zwen@amgen.com
authors.forename: Zai-Qing
authors.initials: ZQ
authors.lastname: Wen
authors.forename: Aylin
authors.initials: A
authors.lastname: Vance
authors.forename: Fabian
authors.initials: F
authors.lastname: Vega
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Cao
authors.forename: Bruce
authors.initials: B
authors.lastname: Eu
authors.forename: Robert
authors.initials: R
authors.lastname: Schulthesis
mesh_terms: D008857:Microscopy, Interference; D011994:Recombinant Proteins / Q000008:administration & dosage; D012827:Silicone Oils / Q000008:administration & dosage* / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013594:Syringes
chemical_list: D011994:Recombinant Proteins; D012827:Silicone Oils