title: Spectrofluorimetric determination of 3-methylflavone-8-carboxylic acid, the main active metabolite of flavoxate hydrochloride in human urine.
abstract: A simple, sensitive and selective spectrofluorimetric method has been developed for the determination of 3-methylflavone-8-carboxylic acid as the main active metabolite of flavoxate hydrochloride in human urine. The proposed method was based on the measurement of the native fluorescence of the metabolite in methanol at an emission wavelength 390 nm, upon excitation at 338 nm. Moreover, the urinary excretion pattern has been calculated using the proposed method. Taking the advantage that 3-methylflavone-8-carboxylic acid is also the alkaline degradate, the proposed method was applied to in vitro determination of flavoxate hydrochloride in tablets dosage form via the measurement of its corresponding degradate. The method was validated in accordance with the ICH requirements and statistically compared to the official method with no significant difference in performance.
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt. Electronic address: hazaza@hotmail.com.
authors.forename: Hala E
authors.initials: HE
authors.lastname: Zaazaa
authors.affiliation: National Organization for Drug Control and Research (NODCAR), 6-Abu Hazem Street, Pyramids Ave., P.O. Box 29, 35521 Giza, Egypt.
authors.forename: Afaf O
authors.initials: AO
authors.lastname: Mohamed
authors.affiliation: National Organization for Drug Control and Research (NODCAR), 6-Abu Hazem Street, Pyramids Ave., P.O. Box 29, 35521 Giza, Egypt.
authors.forename: Maha A
authors.initials: MA
authors.lastname: Hawwam
authors.affiliation: Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, 11562 Cairo, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdelkawy
mesh_terms: D002138:Calibration; D005422:Flavoxate / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics* / Q000652:urine; D005470:Fluorometry / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012997:Solvents / Q000737:chemistry; D013607:Tablets
chemical_list: D012997:Solvents; D013607:Tablets; D005422:Flavoxate; C011504:3-methylflavone-8-carboxylic acid
keywords: 3-Methylflavone-8-carboxylic acid; Flavoxate hydrochloride; Pharmaceutical formulation; Spectrofluorimetry; Urine