Topological structure and chemical composition of inner surfaces of borosilicate vials.

The use of atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS) is described to characterize the inner surfaces of pharmaceutical vials. The two type I borosilicate glasses included in this study slightly differ in their amounts of alkaline oxides. The topography and chemistry of the inner surfaces of vials are predominantly caused by the forming process. A structural and chemical modification of the inner surface of vials was also observed when exposing the surface to different pH conditions and special treatment like washing and sterilization, which are routine operation steps during galenical manufacturing.