title: Development and Validation of an RP-HPLC Method for the Determination of Vinpocetine and Folic Acid in the Presence of a Vinpocetine Alkaline Degradation Product in Bulk and in Capsule Form.
abstract: An alkaline-forced degradation hydrolytic product of vinpocetine was prepared and characterized by 1H-NMR, FTIR spectroscopy, and MS. Subsequently, a simple, selective, and validated reversed-phase HPLC method was developed for the simultaneous estimation of vinpocetine and folic acid in the presence of a vinpocetine alkaline degradation product. Chromatographic separation was achieved using an isocratic mobile phase consisting of acetonitrile-0.02 M KH2PO4 [containing 0.2% (v/v) triethylamine and adjusted to pH 6 with orthophosphoric acid; (80 + 20, v/v)] at a flow rate of 0.9 mL/min at ambient temperature on a Eurospher II C18 (250 × 4.6 mm, 5 μm) column, with UV detection at 280 nm for folic acid and 230 nm for vinpocetine and its alkaline hydrolytic product. Linearity, accuracy, and precision were found to be acceptable over a concentration range of 12.5-200 μg/mL for vinpocetine and 1-16 μg/mL for folic acid. The proposed method was successfully applied for the determination of both drugs and a vinpocetine hydrolysis product in a laboratory-prepared mixture and in a capsule containing both drugs.
authors.affiliation: Cairo University, Faculty of Pharmacy, Pharmaceutical Chemistry Department, Kasr El-Aini St, Cairo 11562, Egypt.
authors.forename: Ehab F
authors.initials: EF
authors.lastname: Elkady
authors.affiliation: National Organization for Drug Control and Research, 6-Abu Hazem St, Pyramids Ave, Giza 35521, Egypt.
authors.forename: Marwa H
authors.initials: MH
authors.lastname: Tammam
authors.affiliation: National Organization for Drug Control and Research, 6-Abu Hazem St, Pyramids Ave, Giza 35521, Egypt.
authors.forename: Ayman A
authors.initials: AA
authors.lastname: Mohamed
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005492:Folic Acid / Q000032:analysis*; D006868:Hydrolysis; D004364:Pharmaceutical Preparations / Q000032:analysis*; D014748:Vinca Alkaloids / Q000032:analysis*
chemical_list: D004364:Pharmaceutical Preparations; D014748:Vinca Alkaloids; C013983:vinpocetine; D005492:Folic Acid