Method For Determination Of Diclofenac Research Articles

A new electrochemical sensing platform for quantitative determination of diclofenac based on gold nanoparticles decorated multiwalled carbon nanotubes/graphene oxide nanocomposite film

ABSTRACT This paper describes a simple method for determination of diclofenac using a gold electrode modified with functionalised multiwalled carbon nanotubes (f-MWCNTs)/graphene oxide (GO) nanocomposite film and gold nanoparticles (AuNPs). Electrochemical deposition method was employed for immobilisation of AuNPs at the surface of f-MWCNTs-GO nanocomposite film. The microscopic structure and morphology of the prepared films at the surface of the electrode were characterised by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the electrochemical behaviour of diclofenac molecules. The effect of several parameters such as pH, electrodeposition time and the amount of nanocomposite controlling the performance of the sensor was examined and they were optimised. The proposed sensor showed an excellent catalytic activity towards the oxidation of diclofenac molecules. The oxidation peak current of diclofenac was linear in the concentration ranges of 0.4–80 µM and 100–1000 µM with a detection limit of 0.09 μM. The modified electrode was used for the quantitative determination of diclofenac in water, tablet and human urine samples where it gave recoveries ranging between 98.8% and 105%

Flow‐Injection Amperometric Method for Determination of Diclofenac in Pharmaceutical Formulations Using a Boron‐Doped Diamond Electrode

AbstractThis paper describes the determination of diclofenac (DCF) in pharmaceutical formulations using flow injection method with multiple pulse amperometric detection. Unmodified boron‐doped diamond (BDD) is used as working electrode and 0.10 mol L−1 sulfuric acid as supporting electrolyte. The system exhibited sharp current response peaks and excellent stability of the analytical signal (RSD=1.0 %, n=10). The linear response range from 5 to 50 µmol L−1 was obtained by using an injected volume of 50 µL, with good correlation coefficient (R=0.998). The limits of detection (LOD) and quantification (LOQ) were found to be 0.14 and 0.46 µmol L−1, respectively. The sampling frequency was calculated about 135 injections h−1.

HPLC Method for Determination of Diclofenac in Human Plasma and Its Application to a Pharmacokinetic Study in Turkey

A simple high-performance liquid chromatography (HPLC) method has been developed for determination of diclofenac in human plasma. The method was validated on Ace C(18) column using UV detection. The mobile phase consisted of 20 mM phosphate buffer (pH 7) containing 0.1% trifluoroacetic acid-acetonitrile (65:35, v/v). Calibration curve was linear between the concentration range of 75-4000 ng/mL. Intra- and inter-day precision values for diclofenac in plasma were less than 3.6, and accuracy (relative error) was better than 5.3%. The limits of detection and quantification of diclofenac were 25 and 75 ng/mL, respectively. Also, this assay was applied to determine the pharmacokinetic parameters of diclofenac in healthy Turkish volunteers who had been given 50 mg diclofenac.

Efficient high performance liquid chromatograph/ultraviolet method for determination of diclofenac and 4′-hydroxydiclofenac in rat serum

A rapid and sensitive high-performance liquid chromatographic method was developed for determination of diclofenac and its major metabolite, 4'-hydroxydiclofenac, in serum from rats treated with diclofenac. The method is simple with a one-step extraction procedure, isocratic HPLC separation, and UV detection at 280 nm. Use of N-phenylanthranilic acid as the internal standard provided good accuracy without interference by endogenous compounds or 5-hydroxydiclofenac, another metabolite of interest. Limits of detection for diclofenac and 4'-hydroxydiclofenac were 0.0225 and 0.0112 microg/ml, respectively. Average extraction efficiencies of diclofenac, 4'-hydroxydiclofenac, and the internal standard were >/=76%. The method was applied to serum collected at 3h after rats were treated with an experimentally useful dosage range of 3, 10 and 50mg/kg diclofenac. Recovery (as a percentage of dose) for the 4'-hydroxy metabolite in serum was found to consistently average from 0.10 to 0.12% following each dosage, whereas recovery of diclofenac in serum declined from 0.45 to 0.37%. Thus, the method is suitable for measurement of a major diclofenac metabolite in experimental studies.