LC-MS tools used to characterize drug degradation products

Researchers in the Department of Pharmaceutical Analysis at the National Institute of Pharmaceutical Education and Research (Punjab, India) have published new research using liquid chromatography–mass spectrometry (LC–MS) tools to characterize degradation products of the nonsteroidal anti-inflammatory drugs piroxicam and meloxicam.

The degradation behaviour of the two drugs was studied by subjecting the drugs individually to hydrolytic (acidic, basic and neutral), oxidative, photolytic and thermal stress. Both drugs showed significant degradation in hydrolytic, oxidative and photoneutral conditions, although they were stable under dry heat and on exposure to light in the solid state. In total, five and four degradation products were formed from piroxicam and meloxicam, respectively. To characterize the degradation products, mass fragmentation pathways of both drugs were established using mass spectrometry–time of flight (MS-TOF), multiple-stage mass spectrometry (MSn), and hydrogen–deuterium (H/D) exchange mass studies, followed by LC–MS-TOF and on-line H/D exchange experiments on the degradation products.

The collected data helped to identify the degradation products of both the drugs. The researchers were able to establish degradation pathways and proposed mechanisms for the formation of the degradation products.

The study was published on-line on 18 October as an advance article in the journal Analytical Methods.