title: Quantitative spot-test analysis of metformin in pharmaceutical preparations using ultraviolet-visible diffuse reflectance spectroscopy.
abstract: A quantitative spot-test for the determination of metformin in pharmaceutical preparations using diffuse UV-visible reflectance is reported. The procedure is quite simple, involving in the formation of a metformin-nickel(II) complex on a glass filter membrane with a later measurement of the reflectance in the spectrophotometer using an integration sphere. The analytical results obtained with commercial products were statistically compared with those resulting from a method recommended by JP and by USP, where complete agreement was observed. The average RSD is 2.5% and the detection (0.009 mol L(-1)) and the quantitation (0.03 mol L(-1)) limits are quite adequate for pharmaceutical analysis.
authors.affiliation: Institute of Chemistry, University of Campinas, P. O. Box 6154, BR-13083-970 Campinas, SP, Brazil. tubino@iqm.unicamp.br
authors.forename: Matthieu
authors.initials: M
authors.lastname: Tubino
authors.forename: Luís Francisco
authors.initials: LF
authors.lastname: Bianchessi
authors.forename: Marta M D C
authors.initials: MM
authors.lastname: Vila
mesh_terms: D005374:Filtration; D007004:Hypoglycemic Agents / Q000032:analysis*; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D008687:Metformin / Q000032:analysis*; D009532:Nickel / Q000737:chemistry; D011199:Potentiometry; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets / Q000032:analysis
chemical_list: D007004:Hypoglycemic Agents; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D012996:Solutions; D013607:Tablets; D009532:Nickel; D008687:Metformin