Identification and characterization of potential impurities of donepezil.
Five unknown impurities ranging from 0.05 to 0.2% in donepezil were detected by a simple isocratic reversed-phase high performance liquid chromatography (HPLC). These impurities were isolated from crude sample of donepezil using isocratic reversed-phase preparative high performance liquid chromatography. Based on the spectral data (IR, NMR and MS), the structures of these impurities were characterised as 5,6-dimethoxy-2-(4-pyridylmethyl)-1-indanone (impurity I), 4-(5,6-dimethoxy-2,3-dihydro-1H-2-indenylmethyl) piperidine (impurity II), 2-(1-benzyl-4-piperdylmethyl)-5,6-dimethoxy-1-indanol (impurity III) 1-benzyl-4(5,6-dimethoxy-2,3-dihydro-1H-2-indenylmethyl) piperidine (impurity IV) and 1,1-dibenzyl-4(5,6-dimethoxy-1-oxo-2,3-dihydro-2H-2-indenylmethyl)hexahydropyridinium bromide (impurity V). The synthesis of these impurities and their formation was discussed.
Krishna Reddy
K V S R
KV
Department of Analytical Research, Discover Research, Dr. Reddy's Laboratories Ltd., Bollaram Road, Miyapur, Hyderabad 500050, India.
Moses Babu
J
J
Kumar
P Anil
PA
Chandrashekar
E R R
ER
Mathad
Vijayavitthal T
VT
Eswaraiah
S
S
Reddy
M Satyanarayana
MS
Vyas
K
K
D002800:Cholinesterase Inhibitors / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D000077265:Donepezil; D007189:Indans / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D010880:Piperidines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D002800:Cholinesterase Inhibitors; D007189:Indans; D010880:Piperidines; D000077265:Donepezil