Identification of a pharmaceutical packaging off-odor using solid phase microextraction gas chromatography/mass...

Area of Science:

• Analytical Chemistry
• Materials Science
• Pharmaceutical Science

Background:

• Off-odors in pharmaceutical packaging can compromise product quality and patient safety.
• Heat stress can induce degradation reactions in packaging materials, leading to volatile compound formation.
• Conventional headspace sampling may fail to detect trace-level odorants.

Purpose of the Study:

• To identify the specific volatile compound responsible for an off-odor in heat-stressed pharmaceutical packaging.
• To evaluate the effectiveness of solid phase microextraction (SPME) coupled with gas chromatography/mass spectrometry (GC/MS) for trace odorant analysis.
• To elucidate the chemical pathway leading to the formation of the identified odorant.

Main Methods:

• Solid phase microextraction (SPME) using a polydimethylsiloxane (PDMS) coated microfiber.
• Gas chromatography/mass spectrometry (GC/MS) for separation and identification of volatile compounds.
• Analysis of heat-stressed pharmaceutical packaging material.

Main Results:

• Ethyl-2-mercaptoacetate was identified as the causative agent of the off-odor.
• The odor compound was present at trace levels, below the detection limit of conventional headspace techniques.
• The formation of ethyl-2-mercaptoacetate resulted from the reaction between ethanol and components of a polyvinyl chloride (PVC)-resin thermal stabilizer.

Conclusions:

• SPME-GC/MS is a powerful technique for identifying trace volatile compounds in pharmaceutical packaging.
• Unanticipated reactions involving residual solvents and packaging additives can lead to significant odor issues.
• Understanding these reactions is crucial for preventing off-odor development in pharmaceutical packaging.