Isolation and identification of the C6-hydroxy and C20-hydroxy metabolites and glucuronide conjugate of methylprednisolone by preparative high-performance liquid chromatography from urine of patients receiving high-dose pulse therapy

High-performance Liquid-chromatographic-Atmospheric-pressure Chemical-ionization Ion-trap Mass-spectrometric Identification of Isomeric C6-hydroxy and C20-hydroxy Metabolites of Methylprednisolone in the Urine of Patients Receiving High-dose Pulse Therapy

“…Figure 2, metabolites of methylprednisolone were observed in the chromatogram obtained from the urine of a patient after a short (0Á5 h) infusion of 1 g methylprednisolone hemisuccinate. The identi®cation of seven metabolites isolated from urine samples has been described elsewhere (Vree et al 1999a). The chromatogram revealed more, minor, metabolites of methylprednisolone; these were identi®ed by LC±MS± MS analysis.…”

“…After development of an analytical HPLC method for methylprednisolone and its hemisuccinate in plasma and urine, it was noticed that only 5% of a high intravenous dose (1 g) could be recovered from the urine, leaving 95% for further metabolism (Figure 1). Application of a mobile-phase gradient indicated that at least seven main metabolites could be detected and identi®ed after isolation (Vree et al 1999a). Nevertheless, minor metabolites could not be isolated.…”

A rapid and sensitive LC–ESI-MS/MS method for detection and quantitation of methylprednisolone and methylprednisolone acetate in rat plasma after intra-articular administration

“…Suitable analytical methods able to quantify low expected plasma concentrations of MP, following local administration of newly developed formulations, are then mandatory to compare their systemic levels with those attained following administration of conventional formulations. A great number of HPLC [12][13][14] and LC-MS [15][16][17][18][19][20] methods for the detection and quantitation of MP and MPA are available in literature, but only LC-MS/MS is adequately specific and sensitive for this purpose. In particular, the use of multiple reaction monitoring (MRM) mode is the most appropriate, due to the specificity and sensitivity attained working with parent-to-product ion transitions.…”

Oesophagocardioplasty for residual dysphagia following multiple pneumatic dilatations for achalasia

“…Metabolites of MP in human urine have been previously detected by GC/MS,22 LC/APCI ion trap MS16 and LC/MS/MS,11, 23 and the structures of many of them have been outlined. While MP metabolites in rat plasma have been described,24–26 there appear to be no reports of the metabolic urinary profile in this species.…”

“…Two metabolites (M5 and M6) were detected with molecular weight (MW) 390. Two structures have already been assigned to metabolites in human urine with [M + H] + ions at m/z 39116, 23 arising from: (a) reduction of the carbonyl function at C20 and simultaneous oxidation of the C21‐OH to a carboxyl function: C20‐OH – C21‐COOH; and (b) oxidation of C6 by the addition of a hydroxyl group: C6‐OH. Both M5 and M6 showed the sequential loss of three molecules of water (product ions at m/z 373, 355 and 337).…”