HPLC method for determination of moxifloxacin in plasma and its application in pharmacokinetic analysis

Ocular bioanalysis of moxifloxacin and ketorolac tromethamine in rabbit lacrimal matrix using liquid chromatography-tandem mass spectrometry

Aim: The fixed-dose combination of moxifloxacin (MOXI) and ketorolac tromethamine (KTR) is widely used for the treatment of bacterial keratitis. Thus, a new LC-MS/MS method was developed to determine MOXI and KTR in lacrimal fluid. Methods: Bioanalysis was performed using a Shimadzu 8050 LC-MS/MS in electrospray ionization-positive mode and the method was validated per US FDA guidelines. Isocratic separation was performed with a Waters Symmetry C18 column using methanol and 0.1% formic acid containing deionized water (85:15, v/v). Results & conclusion: An easy, quick and selective method was established and applied to assess the ocular pharmacokinetic profile of a commercially available formulation containing MOXI and KTR. Based on the pharmacokinetic data, this work describes pharmacokinetics-based dosage regimen calculations and their clinical significance.

A QbD-led simple and sensitive RP-UHPLC method for simultaneous determination of moxifloxacin, voriconazole, and pirfenidone: An application to pharmaceutical analysis

A novel, quick and precise RP-UHPLC analytical method for the simultaneous determination of moxifloxacin (MFX), voriconazole (VCZ) and pirfenidone (PIR) was developed and validated according to the International Conference on Harmonization guidelines using a QbD-driven response surface Box-Behnken design. The developed method was validated considering the selectivity, sensitivity, linearity, accuracy-precision, robustness, stability, limit of detection and limit of quantification, respectively. Resolution between MFX, VCZ and PIR was achieved using a gradient elution protocol against a Waters Symmetry Shield C18 column (150 × 4.6 mm2 , 5 μm) using an Agilent 1290, Infinity II series LC system. The method was applied to quantitatively estimate proprietary and in-house prepared pharmaceutical topical ophthalmic formulations containing MFX, VCZ and PIR at wavelength (λmax ) of 296, 260 and 316 nm. The method is sensitive enough to detect up to 0.1 ppm of analytes in the formulation. The method was further exploited to study and identify the possible degradation products of the analytes. The proposed chromatographic method is simple, economical, reliable and reproducible. In conclusion, the developed method could be applicable for routine quality control analysis of single or combined MFX, VCZ and PIR-containing units or bulk dosage forms in pharmaceutical industries and research organizations working on drug discovery and development.

Validated spectrofluorimetric assay of two co-administered drug mixtures containing hydroxychloroquine with either moxifloxacin or ofloxacin as a drug regimen for hospital-acquired pneumonia in patients with COVID-19

Moxifloxacin and ofloxacin are two broad-spectrum quinolone antibiotics. They are among the most widely used antibiotics, at this time, applied to control the COVID-19 pandemic. Hydroxychloroquine is an FDA-approved drug for the treatment of COVID-19. This work describes a simple, green, selective, and sensitive spectrofluorimetric method for the assay of moxifloxacin and ofloxacin in the presence of hydroxychloroquine, two co-administered mixtures used in the treatment of hospital-acquired pneumonia in patients with COVID-19. Simultaneous assay of hydroxychloroquine and moxifloxacin was carried out in methanol using a direct spectrofluorimetric method (method I) at 375 and 550 nm, respectively, after excitation at 300 nm. The direct spectrofluorimetric assay was rectilinear over concentration ranges 50.0-400.0 and 300.0-2500.0 ng/ml for hydroxychloroquine and moxifloxacin, respectively, with limits of detection (LOD) of 6.4 and 33.64 ng/ml and limits of quantitation (LOQ) of 19.4 and 102.6 ng/ml, respectively, for the two drugs. The assay for hydroxychloroquine and ofloxacin was carried out by measuring the first derivative synchronous amplitude for hydroxychloroquine at the zero crossing point of ofloxacin and vice versa at Δλ = 140 nm (method II). Hydroxychloroquine was measured at 266 nm, while ofloxacin was measured at 340 nm over the concentration range 4-40 ng/ml for hydroxychloroquine and 200-2000 ng/ml for ofloxacin with LOD of 0.467 and 25.3 ng/ml and LOQ of 1.42 and 76.6 ng/ml, respectively, for the two drugs. The two methods were validated following International Conference on Harmonization guidelines and were applied to the analysis of the two drugs in plasma with good percentage recoveries (109.73-93.17%).

Simultaneous estimation of voriconazole, moxifloxacin, and pirfenidone in rabbit lacrimal matrix using LC-MS/MS: an application to preclinical ocular pharmacokinetics

Dynamic emergence of microbial keratitis (MK) requires a promising therapeutic arsenal of antifungal and antibacterial agents like voriconazole (VCZ) and moxifloxacin (MOXI), respectively. Parallelly, another paradigm of MK associated with ulcerative wounds cannot be left unnoticed and requires antifibrotic remedy (pirfenidone, PIR) as an authalic antimicrobial to retain the primordial vision. For designing an effective clinical cure, a combination of these three agents is required at a therapeutic dosage regimen. Following the quest, we have developed a simple and sensitive LC-MS/MS bioanalytical method for simultaneous quantification of VCZ, MOXI, and PIR in rabbit lacrimal fluid. The method was validated as per US-FDA norms using ketoconazole as an internal standard for linearity, accuracy-precision, matrix effect, dilution integrity, selectivity, and stability. The five minutes chromatographic set-up includes isocratic elution with a C18 column using MeOH (80%, v/v) and ultrapure water containing 0.2% formic acid (20%, v/v), respectively. The MS-based analyte detection was achieved in ESI⁺ multiple reaction monitoring mode. The sample extraction was performed using the protein precipitation method with minimal sample size. The validated methodology was employed to determine the ocular pharmacokinetics profile of marketed formulations containing VCZ, MOXI, and PIR in rabbit lacrimal matrix.

Implementation of HILIC-UV technique for the determination of moxifloxacin and fluconazole in raw materials and pharmaceutical eye gel

Hydrophilic interaction liquid chromatography (HILIC) has inherent merits over RP-HPLC in the analyzing of hydrophilic substances. Accordingly, an innovative HILIC-UV methodology is proposed for the simultaneous estimation of ethyl paraben (PRN), fluconazole (FLZ) and moxifloxacin hydrochloride (MOX) in raw materials and pharmaceutical eye gel. The separation process was conducted using Waters XBridge™ HILIC column (100 mm × 4.6 mm, 3.5 μm particle size) at room temperature. Isocratic mobile phase containing acetonitrile: 0.1% triethylamine buffer (90:10, v/v, pH 5.0), was pumped at flow rate 1.0 mL/min and detected at 260 nm. Under these optimized conditions, PRN, FLZ and MOX showed rectilinear relationships with the concentration ranges (0.5–6.0), (5.0–50.0) and (5.0–60.0) μg/mL, respectively. The developed method offered at least fivefold increase in sensitivity within shorter time than the reported methods. Three greenness assessment tools namely: Analytical eco-scale, GAPI and AGREE were exploited to investigate the method's impact on the environment and conduct a comparative study with the reported methods. International council of Harmonization (ICH) guidelines have been followed to calculate validation parameters. The statistical comparison between results of the suggested method and the comparison method showed no discrepancy confirming accuracy of the method.

Moxifloxacin detection based on fluorescence resonance energy transfer from carbon quantum dots to moxifloxacin using a ratiometric fluorescence probe

With an increase in the MOX concentration, the fluorescence intensity of CQDs decreases, whereas the fluorescence intensity of MOX increases gradually.

Determination of levofloxacin, ciprofloxacin, moxifloxacin and gemifloxacin in urine and plasma by HPLC-FLD-DAD using pentafluorophenyl core-shell column: Application to drug monitoring

Concentrations of fluoroquinolones, which are used in the treatment of many bacterial infections, should be monitored in biological fluids as they exhibit concentration-dependent bactericidal activity. In this study, a liquid chromatography method for the determination of levofloxacin, ciprofloxacin, moxifloxacin and gemifloxacin in human urine and plasma was developed for the first time. The efficiency of five different columns for the separation of these fluoroquinolones was compared. Experimental parameters that affect the separation, such as percentage of organic solvent, pH, temperature, gradient shape and detector wavelength, were optimized by a step-by-step approach. Using a pentafluorophenyl core-shell column (100 × 4.6 mm, 2.7 μm), the separation of four analytes was accomplished in <7.5 min. The developed method was validated for the determination of analytes in both urine and plasma with respect to sensitivity, specificity, linearity (r ≥ 0.9989), recovery (79.46-102.69%), accuracy, precision and stability (85.79-111.07%). The intra- and inter-day accuracies were within 89.55-111.94% with relative standard deviations of 0.35-8.05%. The feasibility of method was demonstrated by analyzing urine and plasma samples of patients orally receiving levofloxacin, ciprofloxacin or moxifloxacin. The developed method is suitable for therapeutic drug monitoring of these fluoroquinolones and can be applied to pharmacokinetic and toxicological studies.

Simultaneous Determination of Moxifloxacin and Flavoxate by RP-HPLC and Ecofriendly Derivative Spectrophotometry Methods in Formulations

Simple, fast, and precise reversed-phase (RP)-high-performance liquid chromatography (HPLC) and two ecofriendly spectrophotometric methods were established and validated for the simultaneous determination of moxifloxacin HCl (MOX) and flavoxate HCl (FLX) in formulations. Chromatographic methods involve the separation of two analytes using an Agilent Zorbax SB C18 HPLC column (150 mm × 4.6 mm; 5 µm) and a mobile phase consisting of phosphate buffer (50 mM; pH 5): methanol: acetonitrile in a proportion of 50:20:30 v/v, respectively. Valsartan was used as an internal standard. Analytes were monitored by measuring the absorbance of elute at 299 nm for MOX and 250 nm for FLX and valsartan. Two environmentally friendly spectrophotometric (first derivative and ratio first derivative) methods were also developed using water as a solvent. For the derivative spectrophotometric determination of MOX and FLX, a zero-crossing technique was adopted. The wavelengths selected for MOX and FLX were −304.0 nm and −331.8 nm for the first derivative spectrophotometric method and 358.4 nm and −334.1 nm for the ratio first-derivative spectrophotometric method, respectively. All methods were successfully validated, as per the International Conference on Harmonization(ICH) guidelines, and all parameters were well within acceptable ranges. The proposed analytical methods were successfully utilized for the simultaneous estimation of MOX and FLX in formulations.