RESUMO
A rapid, sensitive and selective pseudoMRM (pMRM)-based method for the determination of solutol HS15 (SHS15) in rat plasma was developed using liquid chromatography/tandem mass spectro-metry (LC–MS/MS). The most abundant ions corresponding to SHS15 free polyethyleneglycol (PEG) oligomers at m/z 481, 525, 569, 613, 657, 701, 745, 789, 833, 877, 921 and 965 were selected for pMRM in electrospray mode of ionization. Purity of the lipophilic and hydrophilic components of SHS15 was estimated using evaporative light scattering detector (ELSD). Plasma concentrations of SHS15 were measured after oral administration at 2.50 g/kg dose and intravenous administration at 1.00 g/kg dose in male Sprague Dawley rats. SHS15 has poor oral bioavailability of 13.74% in rats. Differences in pharmacokinetics of oligomers were studied. A novel proposal was conveyed to the scientific community, where formulation excipient could be analyzed as a qualifier in the analysis of new chemical entities (NCEs) to address the spiky plasma concentration profiles.
RESUMO
Radiofrequency catheter ablation of paroxysmal atrial fibrillation is now being performed routinely with acceptable safety and success rates. Ablation of chronic atrial fibrillation is still in the evolutionary stage. We report a case in which radiofrequency catheter ablation for permanent atrial fibrillation was done in a patient with rheumatic heart disease and a grossly enlarged left atrium.