title: Identification, isolation and characterization of potential degradation product in risperidone tablets.
abstract: One unknown impurity (degradation product) present at a level below 0.1% in the initial samples increased to a level of 0.5% in 6M/40 degrees C/75% RH stability samples of risperidone tablets was detected by gradient reverse-phase high-performance liquid chromatography (HPLC). This impurity was isolated using reverse-phase preparative liquid chromatography. Based on the spectral data the structure of this impurity is characterized as 3-[2-[4-[6-fluoro-1,3-benzoxazol-2-yl]piperidin-1-yl]ethyl]-2-methyl-6,7,8,9-tetrahydro-4H-pyrido[1,2-a] pyrimidin-4-one. Structural elucidation of this impurity by spectral data ((1)H NMR, (13)C NMR, DEPT, MS and IR), formation and mechanism has been discussed in detail.
authors.affiliation: A.P.L. Research Centre, 313 Bachupally, Hyderabad 500072, India.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Bharathi
authors.forename: D Krishnama
authors.initials: DK
authors.lastname: Chary
authors.forename: M Saravana
authors.initials: MS
authors.lastname: Kumar
authors.forename: Rama
authors.initials: R
authors.lastname: Shankar
authors.forename: V K
authors.initials: VK
authors.lastname: Handa
authors.forename: Ramesh
authors.initials: R
authors.lastname: Dandala
authors.forename: A
authors.initials: A
authors.lastname: Naidu
mesh_terms: D014150:Antipsychotic Agents / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004340:Drug Contamination; D004355:Drug Stability; D006358:Hot Temperature; D007555:Isoxazoles / Q000737:chemistry* / Q000302:isolation & purification; D008027:Light; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D008956:Models, Chemical; D015394:Molecular Structure; D018967:Risperidone / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000302:isolation & purification; D013607:Tablets
chemical_list: C528263:3-(2-(4-(6-fluoro-1,3-benzoxazol-2-yl)piperidin-1-yl)ethyl)-2-methyl-6,7,8,9-tetrahydro-4H-pyrido(1,2-a)pyrimidin-4-one; D014150:Antipsychotic Agents; D007555:Isoxazoles; D013607:Tablets; D018967:Risperidone