AVS 58th Annual International Symposium and Exhibition
    Applied Surface Science Division Wednesday Sessions
       Session AS-WeA

Paper AS-WeA8
Characterization of Lubricant Coated Cartridges Using Multiple Surface Analytical Techniques

Wednesday, November 2, 2011, 4:20 pm, Room 102

Session: Correlative Analysis - A Multi-technique Approach for Identification and Structure-Property Relationships
Presenter: Xia Dong, Eli Lilly and Company
Authors: X. Dong, Eli Lilly and Company
Z. Xiao, Eli Lilly and Company
C. Kemp, Eli Lilly and Company
Correspondent: Click to Email
Glide force is a key performance attribute for pharmaceutical injection devices. It is directly impacted by lubricant amount, lubricant distribution, and surface chemistry. However, obtaining accurate information on these lubricant properties has been a challenge within the industry because all of the surfaces are curved. Although ellipsometry has been routinely applied to measure the thickness of individual layers within flat samples, the analysis of multi-layered, curved samples, especially non-destructively, remains difficult. We have modified the sample stage and sample holder of a conventional ellipsometer to make it possible to examine lubricant distribution within drug containers with different geometric configurations and components, including those made of plastic and glass. To overcome the challenge introduced by curved surface, the area of the surface analyzed in any individual experiment is reduced to allow effective focusing of the beam. The mapping of large, curved areas may then be accomplished by assembling multiple individual analyses. The relationship between sprayed volume and lubricant thickness can thus be established through non-destructive analysis by ellipsometry. The surface chemistry of a fluorine containing lubricant was evaluated by FTIR-ATR and XPS, both before and after post-spray treatment. Fluorine concentration remains stable with mild treatment, but lubricant was depleted from the surface after severe treatment. This work demonstrated that the combination of multiple surface analytical tools can enhance our understanding of the device lubrication process.