Structure elucidation and quantification of impurities formed between 6-aminocaproic acid and the excipients citric acid and sorbitol in an oral solution using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy

- 6-aminocaproic acid, citric acid and sorbitol were investigated at 20 and 50-80 °C.
- An amide reaction product, dimer and caprolactam were identified with HR-MS and NMR.
- Minor amounts of degradation products of 6-aminocaproic acid were also observed.
- The stability study at 80 °C represents normal storage conditions at 20 °C.