Migrating components in a polyurethane laminating adhesive identified using gas chromatography/mass spectrometry

Area of Science:

• Analytical Chemistry
• Materials Science
• Pharmaceutical Packaging

Background:

• Pharmaceuticals increasingly utilize plastic packaging, raising concerns about compound migration into drugs.
• Regulatory bodies require thorough analysis of leachable substances from packaging materials.
• Identifying leachable compounds is critical for patient safety and toxicological assessment.

Purpose of the Study:

• To identify migrating components from a sterilization-resistant polyurethane (PUR) adhesive used in pharmaceutical primary packaging.
• To establish a foundation for the quantification and toxicological evaluation of these leachable compounds.

Main Methods:

• Utilized hyphenated mass spectrometry (MS) techniques, including gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS).
• Employed electron impact ionization and chemical ionization for GC/MS, and electrospray ionization for LC/MS.

Main Results:

• Detected 13 migrating substances, with 11 identified as cyclic esters.
• Identified specific cyclic esters formed from adipic acid, isophthalic acid, and various glycols.
• Confirmed a cyclic ester involving isophthalic acid and tetraethylene glycol, and a reaction product of isophorone diisocyanate with methanol.

Conclusions:

• The complementary use of hyphenated MS methods successfully identified leachable compounds in the PUR adhesive.
• This analytical approach facilitates the subsequent quantification and toxicity evaluation of identified leachable compounds.
• The presented methodology is potentially applicable for the qualitative assessment of various polyurethane materials in pharmaceutical packaging.