ABSTRACT
A new reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed for the separation and identification of impurities present in metadoxine. Herein, we report that one of the impurities eluted from the metadoxine sample is 4-deoxypyridoxine hydrochloride (4-DPH). In HPLC analysis, the retention time (RT) of 4-DPH was observed to be at 13.5 min in both the reference and metadoxine samples and the relative retention time (RRT) was 1.71. The presence of 4-DPH in a metadoxine sample was also confirmed by a chromatogram obtained by spiking the 4-DPH standard into the sample. Furthermore, the elution and mass of impurity 4-DPH in metadoxine was proven by LC-mass spectroscopy studies. This method highlights the presence of another unknown impurity that has so far not been observed in earlier methods of metadoxine evaluation. Hence, the developed method achieved superior resolution between metadoxine and impurities and thereby facilitates the production of a purer metadoxine drug.
Subject(s)
Chromatography, Reverse-Phase , Drug Contamination , Chromatography, High Pressure Liquid , Drug Combinations , Mass Spectrometry , Pyridoxine , Pyrrolidonecarboxylic AcidSubject(s)
Angiotensin Receptor Antagonists , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Diuretics/therapeutic use , Glomerular Filtration Rate/drug effects , Glomerular Filtration Rate/physiology , Hyperkalemia/prevention & control , Hyperkalemia/physiopathology , Mineralocorticoid Receptor Antagonists/therapeutic use , Receptors, Angiotensin/therapeutic use , Spironolactone/therapeutic use , Aged , Aged, 80 and over , Creatinine/blood , Female , Heart Failure/complications , Heart Failure/drug therapy , Humans , Hyperkalemia/chemically induced , Male , Treatment FailureABSTRACT
The differential diagnosis for patients with acute renal failure of their native kidneys, as a result of primary intrarenal disease, includes acute tubular necrosis, glomerulonephritis, and interstitial nephritis. The role of MAG3 renography has not been studied in this setting. The authors describe four patients with acute renal failure in whom MAG3 renal imaging reliably identified acute tubular necrosis, as confirmed by follow-up kidney biopsies. In contrast to the poor parenchymal uptake observed in glomerulonephritis and interstitial nephritis, MAG3 shows a distinctive pattern in patients with acute tubular necrosis. For patients with acute renal failure, a renal scan can facilitate decision-making regarding the initiation of therapy.
