title: Optimization and validation of an RP-HPLC method for direct determination of metformin hydrochloride in human urine and in a dosage form.
abstract: A simple, selective, sensitive, accurate, and precise method was developed for determination of metformin hydrochloride (MF) in human urine using RP-HPLC. The method depends upon using an octylsilyl (C8) 5 microm particle size column at ambient temperature with mobile phase consisting of 33 mM sodium dihydrogen phosphate containing 6.38 mM hexanesulfonic acid sodium salt and adjusted to apparent pH 3.0 with phosphoric acid-acetonitrile (93 + 7, v/v) at a flow rate of 1.5 mL/min. Quantitation was achieved with UV detection at 231 nm based on peak area with a linear calibration curve over the concentration range of 0.01-50 microg/mL. The proposed method was applied to the determination of the urinary excretion pattern of MF (the cumulative amounts excreted were calculated without pretreatment of the urine sample) and for determination of the dissolution pattern of MF tablets. The proposed method was completely validated according to the U.S. Food and Drug Administration guidelines.
authors.affiliation: Suez Canal University, Faculty of Pharmacy, Pharmaceutical Analytical Chemistry Department, Ismailia, Egypt.
authors.forename: Alaa
authors.initials: A
authors.lastname: El-Gindy
authors.forename: Mohammed Wafaa
authors.initials: MW
authors.lastname: Nassar
authors.forename: Nasr Mohammed
authors.initials: NM
authors.lastname: El-Abasawy
authors.forename: Khalid Abdel-Salam
authors.initials: KA
authors.lastname: Attia
authors.forename: Maisra
authors.initials: M
authors.lastname: Al-Shabrawi
mesh_terms: D000097:Acetonitriles; D000328:Adult; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D005615:Freezing; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007004:Hypoglycemic Agents / Q000032:analysis* / Q000652:urine*; D007202:Indicators and Reagents; D007700:Kinetics; D008297:Male; D008687:Metformin / Q000032:analysis* / Q000652:urine*; D012015:Reference Standards; D015203:Reproducibility of Results; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets; D013696:Temperature
chemical_list: D000097:Acetonitriles; D007004:Hypoglycemic Agents; D007202:Indicators and Reagents; D013607:Tablets; D008687:Metformin; C032159:acetonitrile