Development of a new ultra-high performance liquid chromatography-tandem mass spectrometry method for determination of ambroxol hydrochloride in serum with pharmacokinetic application

Ambroxol hydrochloride is an expectorant agent, successfully applied in mucolytic therapy for acute and chronic bronchopulmonary diseases. The drug regulates not only mucus secretion but also showed antioxidant, anti-inflammatory and local anesthetic properties. To supplement the pharmacokinetic and toxicological studies of ambroxol, a rapid ultra-high performance liquid chromatography-tandem mass spectrometry method for the quantitation of ambroxol in rabbit serum was developed. A validation of the method was performed as per the ICH guidelines for the validation of bioanalytical methods. The chromatographic separation was achieved in a submicron Kinetex RP-C-18 column (2.1 mmx50 mm, 1.3 mu m) using the no buffer mobile phase. The ESI mass spectrometry in the MRM mode was used with a typical transitions m/z 378.9 -> 263.8 for ambroxol and m/z 455.2 -> 165.0 for IS. Linearity was determined with an average coefficient of determination >0.999 over the dynamic range from 0.5-200 ng/mL with LOD and LOQ of 0.25 and 0.5 ng/mL, respectively. The results of the intra- and inter-day precision and accuracy determined in different days were all found to be within the acceptable limits +/- 15%. The present method was successfully applied to pharmacokinetic study in the rabbits after a single oral dose administration.