Ocular Microbiology and Immunology Group
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2014 OMIG Abstract 9

Microbiological and Chemical Analyses of Alexidine-Plastic Interaction:  Implications for the Worldwide ReNu with MoistureLoc-Related
Fusarium Keratitis Event of 2004-2006
John D. Bullock, MD, MPH, MSc; B. Laurel Elder, PhD; Harry J. Khamis, PhD;
Ronald E. Warwar, MD; Joseph Solch, MS
Wright State University, Dayton, OH

Purpose: Our previous studies indicated that: (1) heating the ReNu with MoistureLoc (RML) solution to 56^oC for 1 week in its high density polyethylene (HDPE) plastic (but not a glass) bottle resulted in decreased ability to inhibit Fusarium organisms [Arch Ophthalmol 2011;129:133-6]; (2) alexidine permeates into the walls of heated ReNu HDPE plastic bottles, thereby diminishing its concentration within the solution [N Eng J Med. 2014;370;1:88-9]. The purpose of the present study was to measure actual alexidine levels and correlate them with our prior microbiological studies.
 
Methods: Using liquid chromatography with tandem mass spectroscopy (LCMS), alexidine levels were measured in heated/unheated ReNu bottles stored for various time periods. These data were compared with results derived from Fourier transform infrared (FTIR) spectroscopy absorptions of methanol extract evaporate residues of formerly alexidine fluid-exposed bottle walls.

Results: Previous FTIR studies showed that there was approximately 3.1 times more alexidine in the wall of the heated than in the room temperature-stored bottle. The present LCMS study similarly showed that there was approximately 3.0 times more alexidine in the walls of the heated bottles. Alexidine levels correlated closely with timed and dilutional microbiological studies and resembled classic exponential saturation curves.

Conclusions: Alexidine levels correlated closely with previously performed microbiological and FTIR studies, strongly suggesting alexidine-HDPE plastic interaction as the pharmaceutical failure mechanism of the worldwide RML-related Fusarium keratitis event of 2004-2006.

Disclosure: N

2014 Agenda and Abstracts | < Previous | Next >