title: Highly sensitive and selective high-performance liquid chromatography method for bioequivalence study of cefpodoxime proxetil in rabbit plasma via fluorescence labeling of its active metabolite.
abstract: Cefpodoxime proxetil (CFP), a broad-spectrum third-generation cephalosporin, has been used most widely in the treatment of respiratory and urinary tract infections. For bioequivalence study of CFP in rabbit plasma, it was necessary to develop a highly sensitive and selective high-performance liquid chromatographic (HPLC) method with fluorescence (FL) detection. The pre-column labeling of cefpodoxime acid (CFA) (active metabolite) with an efficient benzofurazan type fluorogenic reagent, 4-N,N-dimethyl aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole (DBD-F) was carried out in the present study in 100mM borate buffer (pH=8.5) at 50°C for 15min. The obtained fluorescent products were separated on C18 column with an isocratic elution of the mobile phase, which consists of 10mM phosphate buffer (pH=3.5)/CH3CN (70:30, v/v). The fluorescent product (DBD-CFA) was detected fluorimetrically at 556nm with an excitation wavelength of 430nm. Cefotaxime sodium was used as internal standard. The method was validated according to the requirements of US-FDA guidelines. The correlation coefficient of 0.999 was obtained in the concentration ranges of 10-1000ngmL(-1). The limits of detection and quantification (S/N=3) were 3 and 10ngmL(-1), respectively. Plasma CFA levels were successfully determined in rabbit with satisfactory precision and accuracy. The proposed HPLC-FL method was successfully applied to study bioequivalence in rabbits for two formulations of different brands contained CFP (prodrug) in a randomized, two-way, single-dose, crossover study and all pharmacokinetic parameters for the two formulations were assessed.
authors.affiliation: Pharmacognosy and Pharmaceutical Chemistry Department, College of Pharmacy Taibah University, Al Madinah AlMunawarah 30001, Saudi Arabia. sameh_aa@yahoo.com
authors.forename: Sameh
authors.initials: S
authors.lastname: Ahmed
authors.forename: Hanaa M
authors.initials: HM
authors.lastname: Abdel-Wadood
authors.forename: Niveen A
authors.initials: NA
authors.lastname: Mohamed
mesh_terms: D000818:Animals; D015296:Ceftizoxime / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry; D010080:Oxazoles / Q000737:chemistry; D011817:Rabbits; D012680:Sensitivity and Specificity; D013449:Sulfonamides / Q000737:chemistry; D013810:Therapeutic Equivalency; D000097627:Cefpodoxime Proxetil
chemical_list: D015296:Ceftizoxime; D005456:Fluorescent Dyes; D010080:Oxazoles; D013449:Sulfonamides; D000097627:Cefpodoxime Proxetil; C060548:4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole
keywords: Benzofurazan; Bioequivalence study; Cefpodoxime acid; Pharmacokinetic; Prodrug