title: Development and validation of a stability indicating assay of doxofylline by RP-HPLC: ESI-MS/MS, ¹H and ¹³C NMR spectroscopic characterization of degradation products and process related impurities.
abstract: A validated stability indicating RP-HPLC assay of doxofylline was developed by separating its related substances and degradants on LichrocartC18 (250 mm × 4.6 mm; 5 μm) column using 10 mM ammonium acetate and acetonitrile as a mobile phase in a gradient mode of elution at a flow rate of 1.0 mL/min at 30 °C. The column effluents were monitored by a photo diode array detector set at 274 nm. The method was validated in terms of accuracy, precision and linearity as per ICH guidelines. The limits of quantification of doxofylline and impurities were obtained in the range of 0.19-0.36 μg/mL. Forced degradation of doxofylline was carried out under acidic, basic, thermal, photo, peroxide conditions and the degradation products were isolated and characterized by ESI-MS/MS, (1)H and (13)C spectroscopy. The method was successfully applied not only to quantify related substances and degradation products but also assay of doxofylline in bulk drugs. The recoveries of doxofylline and impurities were in the range of 99.00-100.05% and 97.83-99.86% respectively.
authors: Analytical Chemistry Division, Discovery Laboratory, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India. rnrao55@yahoo.com
authors: R Nageswara
authors: RN
authors: Rao
authors: Ch Gangu
authors: ChG
authors: Naidu
authors: K Guru
authors: KG
authors: Prasad
authors: B
authors: B
authors: Santhakumar
authors: Shaik
authors: S
authors: Saida
mesh_terms: D001993:Bronchodilator Agents / Q000032:analysis*; D002247:Carbon Isotopes; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013806:Theophylline / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D001993:Bronchodilator Agents; D002247:Carbon Isotopes; D011522:Protons; D013806:Theophylline; C029797:doxofylline