Method For Determination Of Amoxicillin Research Articles

Poly(4-amino-3-hydroxynaphthalene-1-sulfonic acid) modified glassy carbon electrode for square wave voltammetric determination of amoxicillin in four tablet brands

BackgroundAmoxicillin (AMX), which is one of the β-lactam antibiotics used in the treatment of bacterial infections, is known to have a serious mechanism of resistance necessitating continuous monitoring of its level in pharmaceutical and serum samples.ResultsIn this study, we presented selective, accurate, and precise square wave voltammetric method based on poly(4-amino-3-hydroxynaphthalene-1-sulfonic acid) modified glassy carbon electrode (poly(AHNSA/GCE)) for determination of amoxicillin in four selected tablet brands. Appearance of a peak in the oxidative scan direction without a peak in the reductive direction of cyclic voltammograms of both bare GCE and poly(AHNSA/GCE) with four folds current and much reduced potential on the modified electrode showed catalytic property of the modifier towards oxidation of AMX. While cyclic voltammetric studies of effect of scan rate showed predominantly diffusion controlled oxidation of AMX with one electron participation, effect of pH revealed participation of protons and electrons in a 1:1 ratio. The square wave voltammetric peak current response of the modified electrode for AMX showed linear dependence on the concentration of the spiked standard AMX in the range 10–150 µmol L−1 with 9.9 nmol L−1 LOD. The AMX content of the studied tablet brands were found in the range 97.84–100.78% of the labeled value. Spike recovery results of 99.6–100.5%, and interference recovery results of 95.4–100.8% AMX in the presence of 50–200% of ampicillin and cloxicillin validated the applicability of the method for determination of amoxicillin in tablet formulation.ConclusionIn contrast to the previously reported works on determination of amoxicillin, the present method showed an excellent performance making it a potential method for determination of amoxicillin in real samples including serum samples.

Development and validation of voltammetric method for determination of amoxicillin in river water

Amoxicillin is an antibiotic that can accumulate in aquatic environments and lead to the development of resistant bacteria; thus, its determination is of great importance. In this study, a glassy carbon electrode modified with reduced graphene oxide and Nafion was used as a sensor in a square-wave voltammetry method for determination of amoxicillin in river water samples from Guarapuava city, Brazil. The method was validated, using parameters and statistical tools recommended by the validation guidelines, in the range of 1.8–5.4 μmol L−1 (r = 0.922 and R2 = 85.1%). The analytical curve was constructed using external standard calibration in pure electrolyte, since the matrix effect was not significant. Results of linear regression analysis, lack of fit test and analysis of the residual plots pointed that the linear regression was significant, without lack of fit of linear model and that the variances had homoscedastic distribution. Both coefficients of regression curve were significant and, thus, they were included in the regression equation: Response = 7.0 + 3.5CAMX. The limits of detection and quantification were 0.36 and 1.2 μmol L−1, respectively. The method was selective towards interferents such as humic acids and benzylpenicillin. The relative standard deviations for repeatability and intermediate precision were adequate according to the limits established in literature. The mean recoveries were statistically equal to those obtained through a comparative chromatography method, so, the accuracy of the method was also adequate. Therefore, the method can be applied to the voltammetric determination of amoxicillin in river water, affording reliable and consistent measurements.

Development and Validation of a RP-HPLC Method to Quantify Amoxicillin, Tinidazole, Esomeprazole and Lansoprazole in a Mixture

Present investigation dealt with the developing of a reversed phase-high performance liquid chromatographic method for determination of amoxicillin, tinidazole, esomeprazole and lansoprazole in pure state and ias a mixture. Chromatographic separation was performed isocratically on a LiChrospher® 100 RP-18 column. The flow rate was 1.0 ml/min and the detector was set at 280 nm. The method was developed at ambient temperature with a mobile phase, 40:60 v/v acetonitrile and phosphate buffer (0.001 M, pH 7.6). The selected conditions were applicable for separating amoxicillin, tinidazole, esomeprazole and lansoprazole with retention times 3.11, 5.37, 11.71 and 17.67 min, respectively. The method was validated for parameters including linearity, selectivity, precision and accuracy, limit of detection and limit of quantitation. Linear calibration curves were obtained in the concentration range of 250.0-2000.0, 125-1000.0, 5.0-40.0 and 7.5-60.0 μg/ml for amoxicillin, tinidazole, esomeprazole and lansoprazole, respectively. The proposed method was found to be effective and could be used for quantification of these drugs in routine quality control practice.

Rapid Selective TLC-Densitometry Method for Simultaneous Determination of Amoxicillin and Flucloxacillin in their Pure Forms or in their Pharmaceutical Preparation

A new sensitive, selective and accurate thin-layer chromatography (TLC) - densitometry method developed for simultaneous estimation of Amoxicillin (AMX) and Flucloxacillin (FLX) in their pure forms or their pharmaceutical formulations. Chromatographic separation was completed on aluminum plate pre-coated with silica gel 60 F254 plates using a mobile phase consist of chloroform: methanol: ammonia (5: 2: 0.5 by volume) on silica gel, followed by densitometry detection of spots at 254 nm . Calibration curves were developed in the range of 4-40 μg/spot and 5-30 μg/spot with good correlation for AMX and FLX, respectively. The adopted method was validated according to ICH guidelines and showed good accuracy and precision. The acquired results were statistically compared with the reported method, where no significant difference has been showed. The developed method can be applied for routine analysis of AMX and FLX in their pure forms and capsule dosage form.

Development and analytical validation of a multivariate calibration method for determination of amoxicillin in suspension formulations by near infrared spectroscopy

This paper proposes a new method for determination of amoxicillin in pharmaceutical suspension formulations, based on transflectance near infrared (NIR) measurements and partial least squares (PLS) multivariate calibration. A complete methodology was implemented for developing the proposed method, including an experimental design, data preprocessing by using multiple scatter correction (MSC) and outlier detection based on high values of leverage, and X and Y residuals. The best PLS model was obtained with seven latent variables in the range from 40.0 to 65.0mgmL−1 of amoxicillin, providing a root mean square error of prediction (RMSEP) of 1.6mgmL−1. The method was validated in accordance with Brazilian and international guidelines, through the estimate of figures of merit, such as linearity, precision, accuracy, robustness, selectivity, analytical sensitivity, limits of detection and quantitation, and bias. The results for determinations in four commercial pharmaceutical formulations were in agreement with the official high performance liquid chromatographic (HPLC) method at the 99% confidence level. A pseudo-univariate calibration curve was also obtained based on the net analyte signal (NAS). The proposed chemometric method presented the advantages of rapidity, simplicity, low cost, and no use of solvents, compared to the principal alternative methods based on HPLC.

Determination of Amoxicillin by Flow Injection Analysis using UV‐Detection, Potentiometry, and Conductometry in Pharmaceutical Preparations

A method for direct determination of amoxicillin in pharmaceuticals using flow injection analysis (FIA) with UV detection adjusted at 228 nm, along with potentiometer and condoptometric methods are described. The best carrier solvent system consisted of an aqueous solution of methanol (10% v/v) with pH 9 pumped at a flow rate of 1 mL · min−1. The limit of detection (LOD) and quantification (LOQ) for FIA was calculated to be 3.3×10−7 M (S/N=3) and 1.0×10−7 M (S/N=10), respectively. Two pharmaceutical formulations containing amoxicillin were studied. In the analysis of the tablets, the RSD values were found to be 1.36 and 1.21 and 1.18 (for AMOKLAVIN®), 1.10 1.16 and 1.14 (for REMOXIL®) for FIA, potentiometer, and conduct metric methods, respectively. The proposed methods were applied to the pharmaceutical tablets and good results were obtained. These proposed methods are simple, fast, accurate, precise, and cost effective for the routine determination of amoxicillin in pharmaceutical preparations.

Development and Validation of a Solid-Phase Extraction-Liquid Chromatographic Method for Determination of Amoxicillin in Plasma

A bioanalytic method for the determination of amoxicillin in plasma by hydrophilic interaction solid-phase extraction and liquid chromatography has been developed and validated. Plasma was precipitated with acetonitrile before samples were loaded onto a zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) solid-phase extraction column. Amoxicillin was analyzed by liquid chromatography on an Aquasil (150 x 4.6 mm) LC column with mobile-phase acetonitrile: phosphate buffer (pH 2.5; 0.1 mol/L) (7:93, v/v) and UV detection at 230 nm. A regression model using 1/concentration weighting was found the most appropriate for quantification. The intraassay precision for plasma was 3.3% at 15.0 microg/mL and 10.9% at 0.200 microg/mL. The interassay precision for plasma was 1.8% at 15.0 microg/mL and 7.5% at 0.200 microg/mL. The total-assay precision for plasma over 4 days using a total of 20 replicates was 13.2%, 5.5%, and 3.8% at 0.200 microg/mL, 3.00 microg/mL, and 15.0 microg/mL, respectively. The lower limit of quantification and the limit of detection were 0.050 microg/mL and 0.025 microg/mL, respectively, for 100 microL plasma. Long-term storage stability studies of amoxicillin in plasma indicate that a temperature of -80 degrees C is necessary to prevent degradation of amoxicillin.