title: Spectrophotometric determination of alendronate in pharmaceutical formulations via complex formation with Fe(III) ions.
abstract: The formation of the complex between alendronate, non-chromophoric bisphosphonate drug important for the treatment of a variety of bone diseases, and iron(III) chloride in perchloric acid solution was studied. The stoichiometric ratio of alendronate to Fe(III) ions in the chromophoric complex was determined to be 1:1. The conditional stability constant was logK'(ave)=4.50(SD=0.15), indicating that the Fe(III)-alendronate complex is a complex of medium stability. The optimum conditions for this reaction were ascertained and a spectrophotometric method was developed for the determination of alendronate in the concentration range 8.1-162.5 microg ml(-1), the detection limit being 2 microg ml(-1). The method was validated for the direct determination of alendronate in tablet dosage formulations.
authors.affiliation: Laboratory for Radiation Chemistry and Physics, Vinca Institute of Nuclear Sciences, Belgrade, Yugoslavia.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Kuljanin
authors.forename: Ivana
authors.initials: I
authors.lastname: Janković
authors.forename: Jovan
authors.initials: J
authors.lastname: Nedeljković
authors.forename: Dusica
authors.initials: D
authors.lastname: Prstojević
authors.forename: Valentina
authors.initials: V
authors.lastname: Marinković
mesh_terms: D019386:Alendronate / Q000032:analysis* / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D007501:Iron / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D007501:Iron; D019386:Alendronate