LC and LC-MS/MS studies for identification and characterization of degradation products of d-tubocurarine chloride.

Forced degradation studies of d-tubocurarine (DTC) was carried out in hydrolytic (acidic, alkaline and neutral), thermal, photolytic and oxidative degradation conditions as per International Conference on Harmonization (ICH) guideline Q1A (R2). The present study revealed that DTC is highly sensitive to oxidative degradation conditions even at room temperature whereas the drug was found to be stable in hydrolytic, photolytic and thermal stress conditions. Separation of DTC and its four degradation products (DPs) (DP-I to DP-IV) formed during stress degradation conditions were achieved on Waters Acquity CSH C18 (1.7 µm, 2.1 mm × 100 mm) column using gradient elution with a mobile phase consisting of Eluent-A: 0.1 % Formic acid Eluent-B: acetonitrile achieved successfully. The detection was carried out at 210 nm wavelength and the flow rate was kept at 0.3 mL/min with a 5 μL injection volume. Also, a highly sensitive and robust HRMS/MS/TOF method was established for the identification and characterization of four DPs formed during the stress study. ESI +ve mode was used throughout the study for ionization of all the DPs. The degradation pathway was also established in the study that is never reported earlier.