title: Assay of nitrofurantoin oral suspensions contaminated with 3-(5-nitrofurfurylideneamino)hydantoic acid.
abstract: A reversed-phase high-performance liquid chromatographic (HPLC) analysis of oral suspensions for nitrofurantoin (1) and 3-(5-nitrofurfurylideneamino)hydantoic acid (2), an impurity derived from 1, is presented. The concentration of the impurity ranged from 20 to 300 micrograms/mL in several lots of commercial oral suspensions. Conversion of 1 to 2 with citrate buffer, an excipient in the oral suspension, was achieved; selective hydantoin ring cleavage was accomplished in preference to the generally observed cleavage at the azomethine linkage. The hydantoic acid 2 was synthesized and identified by NMR, IR, TLC, and elemental analysis.
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D006827:Hydantoins / Q000032:analysis*; D009581:Nitrofurans / Q000032:analysis*; D009582:Nitrofurantoin / Q000032:analysis*; D013535:Suspensions
chemical_list: D006827:Hydantoins; D009581:Nitrofurans; D013535:Suspensions; C044787:3-(5-nitrofurfurylideneamino)hydantoic acid; D009582:Nitrofurantoin