Ambroxol-d₅is intended for use as an internal standard for the quantification of ambroxol by GC- or LC-MS. Ambroxol is an expectorant and active metabolite of bromhexine.¹It decreases short-circuit currents in electrically stimulated isolated canine tracheal epithelial cells when applied submucosally (IC₅₀= 60 nM).²Ambroxol (100 µM) decreases IL-13-induced production of mucin 5AC (MUC5AC) in primary human airway epithelial cells and inhibits IL-13-induced decreases in the mucociliary transport rate of endogenous particles in the same cells.³Ambroxol increases phenol red secretion, a marker of expectorant activity, in mice when administered at doses of 30, 60, or 120 mg/kg.⁴Formulations containing ambroxol have been used in the treatment of acute or chronic respiratory conditions.

1.Malerba, M., and Ragnoli, B.Ambroxol in the 21st century: Pharmacological and clinical updateExpert Opin. Drug Metab. Toxicol.4(8)1119-1129(2008) 2.Tamaoki, J., Chiyotani, A., Yamauchi, F., et al.Ambroxol inhibits Na+ absorption by canine airway epithelial cells in cultureJ. Pharm. Pharmacol.43(12)841-843(1991) 3.Seagrave, J., Albrecht, H.H., Hill, D.B., et al.Effects of guaifenesin, N-acetylcysteine, and ambroxol on MUC5AC and mucociliary transport in primary differentiated human tracheal-bronchial cellsRespir. Res.13(1)98(2012) 4.Menezes, P.M.N., Brito, M.C., Sousa de SÁ, P.G., et al.Analytical and pharmacological validation of the quantification of phenol red in a mouse model: An optimized method to evaluate expectorant drugsJ. Pharmacol. Toxicol. Methods98106586(2019)