title: A fast and simple spectrofluorometric method for the determination of alendronate sodium in pharmaceuticals.
abstract: BACKGROUND
  Alendronate sodium enhances bone formation and increases osteoblast proliferation and maturation and leads to the inhibition of osteoblast apoptosis. Therefore, a rapid and simple spectrofluorometric method has been developed and validated for the quantitative determination of it.
  
  
  METHODS
  The procedure is based on the reaction of primary amino group of alendronate with o-phthalaldehyde (OPA) in sodium hydroxide solution.
  
  
  RESULTS
  The calibration graph was linear over the concentration range of 0.0-2.4 μM and limit of detection and limit of quantification of the method was 8.89 and 29 nanomolar, respectively. The enthalpy and entropy of the reaction between alendronate sodium and OPA showed that the reaction is endothermic and entropy favored (ΔH = 154.08 kJ/mol; ΔS = 567.36 J/mol K) which indicates that OPA interaction with alendronate is increased at elevated temperature.
  
  
  CONCLUSIONS
  This simple method can be used as a practical technique for the analysis of alendronate in various samples.
authors.affiliation: Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran ; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Jafar
authors.initials: J
authors.lastname: Ezzati Nazhad Dolatabadi
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Hamishehkar
authors.affiliation: Department of Analytical Chemistry, University of Valencia, Valencia, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: de la Guardia
authors.affiliation: Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran ; Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Hadi
authors.initials: H
authors.lastname: Valizadeh
keywords: Alendronate; Enthalpy; Entropy; O-phthalaldehyde; Spectrofluorimetry