title: Separation and determination of synthetic impurities of sildenafil (Viagra) by reversed-phase high-performance liquid chromatography.
abstract: A simple and rapid high-performance liquid chromatographic method for the separation and determination of process-related impurities of sildenafil was developed. The separation was achieved on a reversed-phase C18 column using acetonitrile-0.05 M potassium dihydrogen orthophosphate (70:30 v/v) as a mobile solvent at a flow rate of 1.0 ml/min and UV detection at 230 nm. The method was used not only for quality assurance, but also for monitoring the chemical reactions during the synthesis of sildenafil. It was found to be specific, precise and reliable for the determination of all process-related impurities of sildenafil in bulk drugs and formulations.
authors.affiliation: Chemistry Section, A. P. State Forensic Science Laboratory, Red Hills, Hyderabad-500 004, India.
authors.forename: Velupula
authors.initials: V
authors.lastname: Nagaraju
authors.forename: Dasari
authors.initials: D
authors.lastname: Sreenath
authors.forename: Jammula Tirumala
authors.initials: JT
authors.lastname: Rao
authors.forename: Ramisetti Nageswara
authors.initials: RN
authors.lastname: Rao
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004340:Drug Contamination; D015394:Molecular Structure; D010879:Piperazines / Q000138:chemical synthesis / Q000737:chemistry*; D011687:Purines; D012680:Sensitivity and Specificity; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate