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Updated: Aug 10, 2026

Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses
Published on: August 30, 2018
A rapid first-derivative spectrophotometric analysis of cephalexin and cephradine in human urine
M E Abdel-Hamid1, M S Mahrous, H G Daabees
1Faculty of Pharmacy, Alexandria University, Egypt.
Abstract:
A rapid, simple, and accurate first-derivative spectrophotometric method has been established for the determination of either cephalexin or cephradine in urine. Quantitative analysis of each antibiotic was achieved by measuring the peak amplitude at 268 nm. The relative and absolute recoveries ranged from 98.90 to 104.00% for cephalexin and from 97.85 to 105.10% for cephradine. The within-day coefficient of variation varied from 3.27 to 6.45%. The applicability of the method for the determination of the cumulative amount of either cephalexin or cephradine excreted unchanged in urine, following an oral dose containing 500 mg of the drug to a human male volunteer, is demonstrated.
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