Simultaneous determination of difloxacin and its primary metabolite sarafloxacin in rabbit plasma

Abstract

Key Words IF~ C2H5 SummaryAn HPLC method with fluorescence detection is presented for the analysis of difloxacin (DIF) and sarafloxacin (SAR) in rabbit plasma using norfloxacin (NOR) as internal standard ( Figure 1). Plasma sample preparations were carried out by adding phosphate buffer (pH 7.4, 0.1 M), followed by extraction with trichloromethane. Fluoroquinolones were separated on a reversed-phase column using an aqueous phosphate solution-acetonitrile (82:18) mobile phase. The concentrations of NOR, SAR and DIF eluting off the colurnn, with retention times of 2.16, 5.60 and 6.20, respectively, were monitored by fuorescence detection at 2ex 338 and 2era 425 nm. The quantitation limit was 12ng mL -1 for SAR and DIE Standard curves were linearly related to concentration in the range from 1 to 1500 ng mL 1. Recovery was determined as 76 % and 70 % for SAR and DIE respectively. Inter-and intraassay coefficients of variation were less than 6 % for all compounds.

Bufferized solvent extraction and HPLC fluorometric detection method for sarafloxacin in pig and chicken muscles

“…Ideally, an internal standard should exhibit physicochemical properties similar to those of the analyte (Garcia et al ., 2000). For this reason, ENRO and CIP (both of which have chemical structures similar to SARA) were utilized as internal standards.…”

Simultaneous determination of enrofloxacin and its primary metabolite, ciprofloxacin, in chicken tissues

“…The HPLC method is widely used for the determination and quantitation of drugs such as fluoroquinolones in biological samples [11,16]. This method presents several advantages such as rapidity, sensitivity, specificity and versatility.…”

“…For this reason, we have used the latter to improve the selectivity of the analytical method [11]. For this reason, we have used the latter to improve the selectivity of the analytical method [11].…”

“…Several microbiological assays have been developed for the determination of antimicrobial activity after administration of ENR or CIP [8 10], but discrepancies with chromatographic methods have been observed and attributed to the presence of antimicrobial activity by active metabolites [11]. For this reason, HLPC methods for the simultaneous determination of ENR, CIP, and SAR were received as a gift.…”

Pharmacokinetics and ocular penetration of grepafloxacin in albino and pigmented rabbits

“…Fluoroquinolones are important therapeutic agents for the treatment of bacterial ocular infections, [1][2][3] with good bactericidal activity against many of the Gram-negative aerobes, as well as limited activity against the Gram-positive bacteria that cause these infections. [4][5][6][7][8] Moreover, they show excellent pharmacokinetic properties, such as long half-life, good tissue distribution, low protein binding, high antimicrobial activity and relatively few side-effects. The newer fluoroquinolones show good penetration into ocular tissues but with a spectrum of activity that includes coagulase-negative staphylococci.…”