Evidences for salbutamol metabolism by respiratory and liver cell lines.

This study aimed to investigate the enantiomeric biotransformation of salbutamol in the human respiratory and liver cells. The cells from the different cell growth cycles were treated with various concentrations of salbutamol sulfate. Salbutamol and its metabolites were analyzed using chiral liquid chromatography and mass spectrometry. There were no metabolites of salbutamol found in the extracellular medium, intracellular, and cell lysate of respiratory cell lines. The S/R ratios of salbutamol were found to be 0.99-1.10 in all cell lines, cell cycles, and salbutamol concentrations in this study. Salbutamol metabolites were found only in intracellular HepG2 cells. The S/R ratios of the salbutamol inside the liver cells were 10 times greater than the S/R ratios of the salbutamol in the liver extracellular medium (0.99-1.10). It is important to note that the S/R ratios of salbutamol in liver cell lysate enzyme were 0.99-1.10 whereas the S/R salbutamol metabolites inside the liver cell were around 1.91-2.14. Both salbutamol and sulfate conjugation metabolites were detected in MS chromatograms with an m/z of 239.2 and 317.6, respectively. Hence, the delivery of salbutamol directly to the respiratory system is a right target that can avoid first-pass metabolism.