Stability of ¹³C‐Urea/PEG Capsules by LC‐APCI‐MS

Abstract

The applicability of liquid chromatography-atmospheric-pressure chemical-ionization-mass spectrometry (LC-APCI-MS) for the determination of 13 C-urea in 13 C-urea=PEG capsules has been studied. It is essential to assess the stability of a newly developed low-dose (38 mg) 13 C-urea=PEG capsule, which will be used for a 13 C-urea breath test ( 13 C-UBT) to detect Helicobacter pylori infection. A standard curve was linear over the concentration range 10-1000 mg=mL. Intra-and inter-day variations were less than 2.75% in APCI-MS. The detection limit was 10 pg when selected ion monitoring (SIM) was employed. The content of 13 C-urea in capsules was within the acceptable range between 95 and 105%. Therefore, it was established that 13 C-urea=PEG capsules were stable under an accelerated stability condition that was set at 40 AE 2 C with relative humidity of 75 AE 5%, during six months by using LC-APCI-MS. This research is the first report that describes LC-APCI-MS analysis of 13 C-urea capsules.