Determination of trovafloxacin in human body fluids by high-performance liquid chromatography

Synthesis and antibacterial activity evaluation of N (7) position-modified balofloxacins

A series of small-molecule fluoroquinolones were synthesized, characterized by HRMS and NMR spectroscopy, and screened for their antibacterial activity against MRSA, P. aeruginosa, and E. coli as model G+/G− pathogens. Compounds 2-e, 3-e, and 4-e were more potent than the reference drug balofloxacin against MRSA and P. aeruginosa (MIC values of 0.0195 and 0.039 μg/ml for 2-e, 0.039 and 0.078 μg/ml for each of 3-e and 4-e, respectively). Analysis of the time-dependent antibacterial effect of compound 2-e toward MRSA showed that in the early logarithmic growth phase, bactericidal effects occurred, while in the late logarithmic growth phase, bacterial inhibition occurred because of concentration effects and possibly the development of drug resistance. Compound 2-e exhibited low toxicity toward normal mammalian cell lines 3T3 and L-02 and tumor cell lines A549, H520, BEL-7402, and MCF-7. The compound was not hemolytic. Atomic force microscopy (AFM) revealed that compound 2-e could effectively destroy the membrane and wall of MRSA cells, resulting in the outflow of the cellular contents. Docking studies indicated the good binding profile of these compounds toward DNA gyrase and topoisomerase IV. ADMET’s prediction showed that most of the synthesized compounds followed Lipinski’s “rule of five” and possessed good drug-like properties. Our data suggested that compound 2-e exhibited potent anti-MRSA activity and is worthy of further investigation.

Analytical Methods for Determining Third and Fourth Generation Fluoroquinolones: A Review

ABSTRACT

Fluoroquinolones of the third and fourth generation posses wide bactericidal activity. Monitoring concentrations of antibacterial agents provides effective therapy and prevents the increase of bacterial resistance to antibiotics. The pharmacodynamic parameters that best describe fluoroquinalone activity are AUC/MIC and Cmax/MIC. Determining the level of this type of drug is essential to reach the effective concentration that inhibits the growth of bacteria. Determining the pharmaceutical formulation confirms the purity of a substance. Many methods have been developed to determine the level of these substances. They involve mainly the following analytical techniques: chromatography, capillary electrophoresis, and spectroscopy. The separation techniques were combined with different measuring devices, such as ultraviolet (UV), fluorescence detector (FLD), diode array detector (DAD), and mass spectrometry (MS). The analytical procedures require proper sample pre-conditioning such as protein precipitation, extraction techniques, filtration, or dilution. This paper reviews the reported analytical methods for the determining representatives of the third and fourth generation of fluoroquinolones. Attention was paid to pre-conditioning of the samples and the applied mobile phase. This report might be helpful in the selection of the proper procedure in determining the abovementioned drugs in different matrices.

GRAPHICAL ABSTRACT

Quantitation of PGE9509924, a novel, nonfluorinated quinolone, in rat plasma using liquid chromatography electrospray-tandem mass spectrometry following solid-phase extraction sample clean-up in a 96-well format

PGE9509924, a novel nonfluorinated quinolone, is a potent antibacterial agent with a broad spectrum of activity. A semi-automated method using 96-well format, solid-phase extraction has been developed for quantitating PGE9509924 in rat plasma. The Waters Oasis HLB extraction plate containing a polymeric packing material was found to give the best overall recoveries. All liquid transfer steps other than aliquoting the plasma are accomplished using a 96-channel pipettor. Reverse-phase HPLC with electrospray/MS/MS detection using selective reaction monitoring is used to quantitate the samples. Stable isotopically labeled PGE9509924 is used as the internal standard. The assay is linear over the range from 0.01 to 10 ug/ml. Excellent precision is obtained within a single run and between multiple runs performed on different days. CVs of <6% were observed. The combination of the semi-automated, 96-well parallel sample processing and the short runtime on the LC/MS/MS results in a high throughput assay with reduced operator interaction.

Serum bactericidal activity of trovafloxacin, in combination with cefepime or amikacin, in healthy volunteers

OBJECTIVE

To investigate the phamacokinetics and serum bactericidal activities (SBAs) of trovafloxacin, cefepime and amikacin alone and trovafloxacin in combination with cefepime or amikacin, so that the most favorable combination with trovafloxacin can be determined.

METHODS

In this open, randomized, crossover study, 12 healthy volunteers (six females, six males; mean age +/- SD, 25.1 +/- 2.6 years) received an infusion of either 300 mg of alatrovafloxacin or 2000 mg of cefepime or 6 mg/kg body weight amikacin alone, or 300 mg of alatrovafloxacin plus 2000 mg of cefepime or plus 6 mg/kg body weight amikacin. The SBAs against Pseudomonas aeruginosa, Staphylococcus aureus (11 strains each), Citrobacter freundii and Acinetobacter spp. (10 strains each) 1, 10 and 24 h after drug administration were measured by a standard microdilution method. Concentrations of trovafloxacin, cefepime and amikacin in serum and urine were analyzed before and up to 10 and 12 h, respectively, after drug infusion.

RESULTS

Significant synergistic effects on SBA were observed with the combination of trovafloxacin and cefepime against P. aeruginosa, S. aureus and Acinetobacter spp. 1 h after drug administration, and against Citrobacter freundii 1, 10 and 24 h after drug administration. The combination of trovafloxacin and amikacin showed significant synergistic effects against P. aeruginosa, S. aureus and C. freundii 1 h after drug administration. The combination of trovafloxacin and cefepime was, in general, more active than the combination of trovafloxacin and amikacin. No significant differences in the serum concentrations of trovafloxacin were observed between single and combined administration. However, the maximal concentration of cefepime was significantly lower when it was used in combination with trovafloxacin.

CONCLUSION

Our study suggests a favorable interaction between trovafloxacin and cefepime. This combination showed more synergistic bactericidal activity against most of the test strains compared to the combination of trovafloxacin and amikacin. However, for P. aeruginosa, the bactericidal activity of cepefime alone was higher than that of the combination with trovafloxacin.

Determination of the antibacterial trovafloxacin by differential-pulse adsorptive stripping voltammetry

A differential-pulse adsorptive stripping voltammetric method for the determination of trace amounts of the antibacterial trovafloxacin (TRFLX) is proposed. The optimal experimental parameters for the drug assay were: accumulation potential=-0.30 V (vs. Ag/AgCl), accumulation time=120 s, pulse amplitude=50 mV and scan rate=5 mV s(-1) in Britton-Robinson buffer (pH 4.5). The linear concentration range of application was 2.0-20.0 ng ml(-1) of TRFLX, with a relative standard deviation of 3.6% (for a level of 5.0 ng ml(-1)) and a detection limit of 0.6 ng ml(-1). The method was applied to determination of TRFLX in human urine and serum samples. It was validated using HPLC as a reference method. Recovery levels of the method reached 100% in all cases

Separation of levofloxacin, ciprofloxacin, gatifloxacin, moxifloxacin, trovafloxacin and cinoxacin by high-performance liquid chromatography: application to levofloxacin determination in human plasma

A selective, sensitive and accurate liquid chromatographic method with UV and fluorescence detection was developed, validated and applied for the determination of fluoroquinolones in human plasma. The effects of mobile phase composition, ion-pair and competing-base reagents, buffers, pH, and acetonitrile concentrations were investigated on the separation of six quinolones (cinoxacin, levofloxacin, ciprofloxacin, gatifloxacin, moxifloxacin and trovafloxacin). Sample preparation was carried out by adding internal standard and displacing agent and processing by ultrafiltration. This method uses ultraviolet and fluorescence detection and separation using a C(18) column. The recovery, selectivity, linearity, precision, and accuracy of the method were evaluated from spiked human plasma samples. The method was successfully applied to patient plasma samples in support of a levofloxacin pharmacokinetic study.

Determination of trovafloxacin in human serum by time resolved terbium-sensitised luminescence

A sensitive time-resolved luminescence method for the determination of trovafloxacin is described. The method is based on the time-resolved luminescence signal from the terbium(III)-trovafloxacin complex, in a micellar solution of sodium dodecyl sulfate (SDS), using a chemical deoxygenation agent (Na(2)SO(3)). The method allows the determination of 20-450 ng ml(-1) of trovafloxacin in 7.5 mM SDS solution containing 0.16 M acetic acid-sodium acetate buffer (pH 6.0) and 7.5 mM Na(2)SO(3) with lambda(exc)=270 nm and lambda(em)=546 nm. In these experimental conditions luminescence signal for trovafloxacin increases 20-fold with respect to native fluorescence of the compound in aqueous solution at pH 6.5. Terbium-sensitised luminescence was applied to trovafloxacin determination in human serum, spiked at levels found after drug administration at normal clinical doses. Recovery is 90+/-1% and day-to-day precision is 3.5%. The proposed method tolerates high concentrations of other co-administrated drugs and excipients.

Comparative pharmacokinetics of ciprofloxacin, gatifloxacin, grepafloxacin, levofloxacin, trovafloxacin, and moxifloxacin after single oral administration in healthy volunteers

In an open, randomized, six-period crossover study, the pharmacokinetics of ciprofloxacin, gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin, and trovafloxacin were compared after a single oral dose in 12 healthy volunteers (6 men and 6 women). The volunteers received 250 mg of ciprofloxacin, 400 mg of gatifloxacin, 600 mg of grepafloxacin, 500 mg of levofloxacin, 400 mg of moxifloxacin, and 200 mg of trovafloxacin. The concentrations of the six fluoroquinolones in serum and urine were measured by a validated high-performance liquid chromatography method. Blood and urine samples were collected before and at different time points up to 48 h after medication. Levofloxacin had the highest peak concentration (C(max), in micrograms per milliliter) (6.21+/-1.34), followed by moxifloxacin (4.34+/-1.61) and gatifloxacin (3.42+/-0.74). Elimination half-lives ranged from 12.12+/-3.93 h (grepafloxacin) to 5.37+/-0.82 h (ciprofloxacin). The total areas under the curve (AUC(tot), in microgram-hours per milliliter) for levofloxacin (44.8+/-4.4), moxifloxacin (39.3+/-5.35), and gatifloxacin (30+/-3.8) were significantly higher than that for ciprofloxacin (5.75+/-1.25). Calculated from a normalized dose of 200 mg, the highest C(max)s (in micrograms per milliliter) were observed for levofloxacin (2.48 +/-0.53), followed by moxifloxacin (2.17+/-0.81) and trovafloxacin (2.09+/-0.58). The highest AUC(tot) (in microgram-hours per milliliter) for a 200-mg dose were observed for moxifloxacin (19.7+/-2.67) and trovafloxacin (19.5+/-3.1); the lowest was observed for ciprofloxacin (4.6+/-1.0). No serious adverse event was observed during the study period. The five recently developed fluoroquinolones (gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin, and trovafloxacin) showed greater bioavailability, longer half-lives, and higher C(max)s than ciprofloxacin.