title: Determination of methenamine, methenamine mandelate and methenamine hippurate in pharmaceutical preparations using ion-exchange HPLC.
abstract: An ion-exchange column high-performance liquid chromatography (HPLC) method has been developed for the determination of methenamine in methenamine and methenamine hippurate pharmaceutical preparations. The HPLC method uses a Zorbax SCX-300 column with acetonitrile-0.1M sodium perchlorate monohydrate (pH 5.8) (70:30, v/v) as the mobile phase at the flow rate of 1 mL/min. UV-detection was at 212 nm. The linear concentration plots for methenamine were linear over the concentration range of 0.25-50mM for methenamine and methenamine mandelate standards. The intra-day RSD precision was <1.25%, and for inter-day, <1.85%. The peaks for mandelic acid, hippuric acid and the other ingredients from placebo tablets do not interfere with the analysis for methenamine. The accuracy of this method was shown to be 99-101% by measuring the recovery of methenamine from spiked placebo tablets. The assay of methenamine from methenamine hippurate tablets and from a urinary antiseptic tablet containing methenamine were in the range of 98-102%. This HPLC method is a fast, simple and straightforward method for the analysis of methenamine in pharmaceutical preparations.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Avenue, Boston, MA 02115, USA.
authors.forename: Chiravi
authors.initials: C
authors.lastname: Pavitrapok
authors.forename: David A
authors.initials: DA
authors.lastname: Williams
mesh_terms: D000892:Anti-Infective Agents, Urinary / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006626:Hippurates / Q000032:analysis*; D007202:Indicators and Reagents; D008333:Mandelic Acids / Q000032:analysis*; D008709:Methenamine / Q000031:analogs & derivatives* / Q000032:analysis; D012015:Reference Standards; D015203:Reproducibility of Results; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013607:Tablets
chemical_list: D000892:Anti-Infective Agents, Urinary; D006626:Hippurates; D007202:Indicators and Reagents; D008333:Mandelic Acids; D012996:Solutions; D013607:Tablets; C023055:methenamine mandelate; D008709:Methenamine; C011481:methenamine hippurate