The search of potential inhibitors of the AcrAB-TolC system of multidrug-resistant Escherichia coli: an in silico approach.

The number of infections caused by multidrug antibiotic resistance (MDR) species is increasing globally. The efflux pump system, AcrAB-TolC, confers Escherichia coli resistance to many antibiotics and results in poor treatment outcomes. Different rational drug design techniques were employed to search for a safe and effective AcrAB-TolC system inhibitor. Ligand docking was performed to analyze the binding of different ArcB substrates and/or inhibitors in the different AcrAB crystal structure binding sites. The validated docking site using the established docking preferences was used to perform virtual high-throughput screening on a large library of compounds. Domperidone, a known and safe over-the-counter antiemetic drug, was proposed as an effective ArcB inhibitor. Microbiological studies confirmed the computational results and domperidone reversed the resistance to the antibiotics: levofloxacin and ciprofloxacin in the MDR E. coli stains with an effect that surpassed the effect of the known efflux pump inhibitor, reserpine. In addition, it was able to increase both antibiotic effects on susceptible strains. This finding suggests that the antibiotic-domperidone combination can be used clinically to treat infections caused by multidrug-resistant E. coli strains.

Synthesis of molecular imprinted polymers for selective extraction of domperidone from human serum using high performance liquid chromatography with fluorescence detection.

In this study a novel method is described for selective quantization of domperidone in biological matrices applying molecular imprinted polymers (MIPs) as a sample clean up procedure using high performance liquid chromatography coupled with a fluorescence detector. MIPs were synthesized with chloroform as the porogen, ethylene glycol dimethacrylate as the crosslinker, methacrylic acid as the monomer, and domperidone as the template molecule. The new imprinted polymer was used as a molecular sorbent for separation of domperidone from serum. Molecular recognition properties, binding capacity and selectivity of MIPs were determined. The results demonstrated exceptional affinity for domperidone in biological fluids. The domperidone analytical method using MIPs was verified according to validation parameters, such as selectivity, linearity (5-80ng/mL, r(2)=0.9977), precision and accuracy (10-40ng/mL, intra-day=1.7-5.1%, inter-day=4.5-5.9%, and accuracy 89.07-98.9%).The limit of detection (LOD) and quantization (LOQ) of domperidone was 0.0279 and 0.092ng/mL, respectively. The simplicity and suitable validation parameters makes this a highly valuable selective bioequivalence method for domperidone analysis in human serum.

HPTLC determination of rabeprazole and domperidone in capsules and its validation.

This paper describes a validated high-performance thin-layer chromatography (HPTLC) method for simultaneous estimation of rabeprazole (RA) and domperidone (DO) in pure powder and in capsule formulations. An HPTLC method separation is achieved on an aluminum sheet of silica gel 60F(254) using ethyl acetate-methanol-benzene-acetonitrile (30:20:30:20 v/v) as mobile phase. Quantitation is achieved with UV detection at 287 nm over a concentration range of 400-1200 ng/spot and 600-1800 ng/spot with mean recovery of 99.82 +/- 0.74 and 99.43 +/- 0.68 for RA and DO, respectively, in the HPTLC method. This method is simple, precise, and sensitive, and it is applicable for the simultaneous determination of RA and DO in pure powder and in capsule formulation.

Simultaneous estimation of pantoprazole and domperidone in pure powder and a pharmaceutical formulation by high-perfomance liquid chromatography and high-performance thin-layer chromatography methods.

This paper describes validated high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC) methods for the simultaneous estimation of pantoprazole (PANT) and domperidone (DOM) in pure powder and capsule formulations. The HPLC separation was achieved on a Phenomenex C18 column (250 mm id, 4.6 mm, 5 pm) using 0.01 M, 6.5 pH ammonium acetate buffer-methanol-acetonitrile (30 + 40 + 30, v/v/v, pH 7.20) as the mobile phase at a flow rate of 1.0 mL/min at ambient temperature. The HPTLC separation was achieved on an aluminum-backed layer of silica gel 60F254 using ethyl acetate-methanol (60 + 40, v/v) as the mobile phase. Quantification was achieved with ultraviolet (UV) detection at 287 nm over the concentration range 400-4000 and 300-3000 ng/mL with mean recovery of 99.35+/-0.80 and 99.08+/-0.57% for PANT and DOM, respectively (HPLC method). Quantification was achieved with UV detection at 287 nm over the concentration range 80-240 and 60-180 ng/spot with mean recovery of 98.40+/-0.67 and 98.75+/-0.71% for PANT and DOM, respectively (HPTLC method). These methods are simple, precise, and sensitive, and they are applicable for the simultaneous determination of PANT and DOM in pure powder and capsule formulations.

Multi-criteria decision making approach and experimental design as chemometric tools to optimize HPLC separation of domperidone and pantoprazole.

This paper deals with multiple response simultaneous optimization using the Derringer's desirability function for the development of a reversed-phase HPLC method for the simultaneous determination of domperidone and pantoprazole in commercial pharmaceutical preparations. Twenty experiments, taking the retention factor of the first peak, the two resolutions, and three retention times as the responses with three important factors, mobile phase composition, buffer molarity and flow rate, were used to design mathematical models. The experimental responses were fitted into a second order polynomial and the six responses simultaneously optimized to predict the optimum conditions for the effective separation of the studied compounds. The optimum assay conditions were: methanol-acetonitrile-dipotassium hydrogen phosphate (pH 7.0; 15.3 mM) (20:33:47, v/v/v) as the mobile phase and at a flow rate of 1.19 ml/min. While using this optimum condition, baseline separation with a minimum resolution of 2.0 and a run time of less than 6 min were achieved. The method showed good agreement between the experimental data and predictive value throughout the studied parameter space. The optimized assay condition was validated according to ICH guidelines to confirm specificity, linearity, accuracy and precision.