Extractables and Leachables study: identification of a label contaminant in ophthalmic solution

Synopsis

The current sophisticated technologies provide powerful new approaches for identification and quantification of E&L compounds. A brief review of the capabilities of a conventional analytical laboratory will be discussed here, a challenging “case of study” concerning  the primary packaging of an ophthalmic solution being presented. While the pivotal role of pharmaceutical packaging to guarantee product integrity is perfectly understandable, nowadays accomplishment of marketing needs or regulatory requirements  is becoming more and more complex. This makes the E&L study more difficult  due to the numerosity of possible sources and the substantial differences in the chemical nature of the potential contaminants. In fact, not only plastics and elastomeric materials can be contaminants but also inks, adhesives, secondary packaging could be sources of extractables and leachables. Given the potential toxicological risk of these compounds, their identification and quantitative evaluation is crucial to minimize patient safety concerns about exposure to E&L. Often, only a combination of different analytical techniques, including LC-DAD, LC-HRMS (Orbitrap or QTOF), GC-MS or GC-HRMS (Orbitrap or QTOF) can lead to the identification of unknown organic contaminants thus avoiding expensive and long toxicological evaluations. The final confirmation that the identification is correct could come from a “preparative” LC approach finalized to isolate analytes for NMR investigation. This presentation describes the application of all these procedures for the identification of a substance present in a commercial ophthalmic solution. The complementarity of the mentioned techniques allowed to identify the unknown contaminant as 2-hydroxy-2-methylpropiophenone, an analyte present in adhesive labels.