Hepatic in vitro metabolism of peptides; Comparison of human liver S9, hepatocytes and Upcyte hepatocytes with cyclosporine A, leuprorelin, desmopressin and cetrorelix as model compounds

The number of approved peptide therapeutics has increased significantly in recent years. Peptide have many advances over small molecule drugs, such as higher affinity to target and lower toxicity profiles. Although peptide-like drugs are mainly metabolized/catabolized the body for smaller peptides amino acids, metabolite identification still an essential part their development, especially if structure contains modified also identify metabolic soft spots enabling modification more stable sequence. use human derived vitro systems is important tool when investigating metabolism comparison results by various hepatic was investigated here. Peptides were incubated several different liver-derived subcellular cellular incubation systems, i.e. liver S9 fraction, suspended cryo-preserved primary hepatocytes plated Upcyte hepatocytes. Samples collected at time points analysed UPLC/HR-MS-method developed purpose. Both substrate disappearance formation monitored, compared. fraction formed highest metabolites leuprorelin cetrorelix, while desmopressin cyclosporin, produced similar Interestingly, not only but cetrorelix showed whose CYP (NADPH) dependent S9. For that NADPH dependency with S9, detected hepatocytes, even though these reactions played a major role hydrolytic very between profiles matched better without NADPH, which may be caused cell uptake rate limitation or then processes stressed CYP-mediated processes.