Simple liquid chromatography–tandem mass spectrometry method for determination of novel anti-methicillin-resistant Staphylococcus aureus fluoroquinolone WCK 771 in human serum

Chemistry, Biological Properties and Analytical Methods of Levonadifloxacin: A Review

Increased use of antibiotics globally has led to the threat of antibiotic resistance; this drove the urge of researchers toward discovering more potent and broad-spectrum antibiotics. Levonadifloxacin (LND) is the very first antibiotic developed by an Indian company Wockhardt. It is S (-) isomer of another broad-spectrum antibiotic Nadifloxacin which is used topically for skin, soft tissue bacterial infection. LND belongs to the benzo quinolizine category which is a subclass of fluoroquinolone, indicated for ABSSIS, CABP, and other infections including diabetic foot infection; formulated as l-arginine salt of levonadifloxacin (WCK177) for IV and l-alanine ester mesylate salt as alalevonadifloxacin (WCK2349) for oral administration. It generally shows dominant antibacterial activity against Gram-negative, and positive bacterial infections, particularly toward methicillin-resistant Staphylococcus aureus (MRSA) by dual inhibition of DNA gyrase and topoisomerase IV. Producing quality product that complies to regulatory requirements is a big concern for pharma industries. To this context, validated analytical methods for routine quality control are essential for quantification of LND as an API alone and together with pharmaceutical formulations. This review suggests therapeutic, pharmacological, and analytical aspects regarding the novel drug LND and particularly focuses on discussing various reported analytical methods present for analytical or bioanalytical estimation of the drug and suggest to develop a simple and validated method which also complies to green chemistry.

Identification of metabolites of novel Anti-MRSA fluoroquinolone WCK 771 in mouse, rat, rabbit, dog, monkey and human urine using liquid chromatography tandem mass spectrometry

WCK 771 is an l-arginine salt of levonadifloxacin (LND) being developed in intravenous dosage form and has recently completed a phase III trial in India. The pharmacokinetics of WCK 771, a novel anti-MRSA fluoroquinolone, were examined in mice, rats, rabbits, dogs, monkeys and humans after systemic administration during pre-clinical and clinical investigations. Urine and serum were evaluated for identification of metabolites. It was observed that LND mainly follows phase II biotransformation pathways. All of the species showed a different array of metabolites. In mice, rabbit and dog, the drug was mainly excreted in the form of O-glucuronide (M7) and acyl glucuronide (M8) conjugates, whereas in rat and human major metabolite was sulfate conjugate (M6). Monkeys exhibited equal distribution of sulfate (M6) and glucuronide conjugates (M7, M8). In addition to these three major phase II metabolites; five phase I oxidative metabolites (M1, M2, M3, M4 and M5) were identified using liquid chromatography tandem mass spectrometry. Out of these eight metabolites M2, M3, M5, M7 and M8 are reported for the first time.

Electrocardiographic Effects of a Supratherapeutic Dose of WCK 2349, a Benzoquinolizine Fluoroquinolone

The purpose of this study was to measure the electrocardiographic (ECG) effects of WCK 2349 (the L‐alanine ester prodrug of levonadifloxacin) at a supratherapeutic oral dose of 2,600 mg. A total of 48 healthy volunteers were randomized to treatment with placebo, WCK 2349, or oral moxifloxacin, 400 mg, in a crossover‐designed thorough QT study. A supratherapeutic mean maximum levonadifloxacin concentration (C_max) of 43.3 μg/mL was achieved at 3.1 hours. A therapeutic dose of 1,000 mg b.i.d. in a previous study in patients resulted in a C_max of 17.8 μg/mL. WCK 2349 exerted no significant effect on baseline‐ and placebo‐corrected QTcF (QT interval corrected for heart rate (HR) by the Fridericia formula), QRS, or PR interval. HR was transiently accelerated by a maximum of 14.4 (95% confidence interval, 11.80–16.92) beats per minute (bpm) at 3 hours. Concentration–effect modeling predicted a mean increase of 8.0 bpm at C_max at the standard therapeutic dose. A therapeutic dose of 1,000 mg b.i.d. of WCK 2349 is not expected to cause clinically significant ECG effects, except for a possible transient increase in HR, which seems to be clinically insignificant.

Intrapulmonary Pharmacokinetics of Levonadifloxacin following Oral Administration of Alalevonadifloxacin to Healthy Adult Subjects

Alalevonadifloxacin (WCK 2349) is a novel l-alanine ester prodrug of levonadifloxacin that is being developed as an oral fluoroquinolone antibiotic. The primary objective of this study was to determine and compare plasma, epithelial lining fluid (ELF), and alveolar macrophage (AM) concentrations of levonadifloxacin following oral administration of alalevonadifloxacin to healthy adult subjects. Levonadifloxacin concentrations in plasma, ELF, and AM samples from 30 healthy subjects were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) following oral dosing of alalevonadifloxacin (1,000 mg twice daily for 5 days). Six subjects were assigned to each bronchoalveolar lavage (BAL) fluid sampling time, i.e., 2, 4, 6, 8, or 12 h after the ninth oral dose. Noncompartmental pharmacokinetic (PK) parameters were determined from serial total plasma concentrations collected over a 12-h interval following the first and ninth oral doses. Penetration ratios were calculated from the areas under the concentration-time curves from 0 to 12 h (AUC_0-12) for plasma, ELF, and AM by using mean (and median) concentrations at each BAL sampling time. Unbound plasma concentrations (∼85% plasma protein binding) were used to determine site-to-plasma penetration ratios. Plasma PK parameter values for levonadifloxacin were similar after the first and ninth doses. The respective AUC_0-12 values based on mean ELF and AM concentrations were 172.6 and 35.3 mg · h/liter, respectively. The penetration ratios for ELF and AM levonadifloxacin concentrations to unbound plasma levonadifloxacin concentrations were 7.66 and 1.58, respectively. Similar penetration ratios were observed with median concentrations. The observed plasma, ELF, and AM concentrations of levonadifloxacin support further studies of alalevonadifloxacin for treatment of lower respiratory tract bacterial infections caused by susceptible pathogens. (This study has been registered at ClinicalTrials.gov under identifier NCT02253342.).

Quantum dot based multiplex fluorescence quenching immune chromatographic strips for the simultaneous determination of sulfonamide and fluoroquinolone residues in chicken samples

Quantum dot based fluorescence quenching immune chromatographic strips for simultaneous determination of sulfonamides and fluoroquinolones.