Determination Of Ketoprofen Research Articles

Comparative narrow‐bore high‐performance liquid chromatographic determination of ketoprofen in horse plasma

Comparative narrow‐bore high‐performance liquid chromatographic determination of ketoprofen in horse plasma

On-line solvent recycling: a tool for the development of clean analytical chemistry in flow injection Fourier transform infrared spectrometry. Determination of ketoprofen

A flow injection strategy has been developed for the direct determination of ketoprofen in pharmaceuticals by Fourier transform infrared spectrometry also incorporating a distillation unit which allows the carbon tetrachloride employed to dissolve samples and standards and used as a carrier to be recovered on-line. The system developed permits a drastic reduction of reagent consumption and easy and fast sampling and cleaning of the measurement cell. For the quantification of ketoprofen in pharmaceuticals the carbonyl bands at 1712 and 1666 cm −1 were employed and the developed method provided a 3 σ limit of detection of 0.04 mg ml −1, a dynamic range up to 10 mg ml −1 and typical coefficient of variation values between 1.6 and 3%, with a sample injection frequency >42 h −1. Accurate and precise results were obtained in the analysis of real pharmaceutical samples.

Chiral and nonchiral determination of ketoprofen in pharmaceuticals by capillary zone electrophoresis

The new method for the enantiomeric resolution of various 2-arylpropionic acids by capillary zone electrophoresis (CZE) using heptakis-tri-O-methyl-β-cyclodextrin as chiral selector was applied to the determination of ketoprofen in different commercially-available pharmaceutical preparations. The analyte was determined under chiral and nonchiral conditions (viz. in the presence and absence of 50 m M heptakis-tri-O-methyl-β-cyclodextrin in the background electrolyte), with significantly similar results and relative standard deviations from 1.2 to 6.5% in both cases. The limits of detection and determination for the inactive enantiomer, R-(−)-ketoprofen, were calculated to be 7.0·10 −7 and 1.6·10 −6 M, respectively. The proposed method was successfully used to determine enantiomeric purity in the drugs studied, with results comparable to those provided by the chiral HPLC method.

Tissue extraction and high-performance liquid chromatographic determination of ketoprofen enantiomers

Local transcutaneous delivery of non-steroidal anti-inflammatory drugs avoids gastrointestinal side effects and concentrates drugs in the intended tissues. An extraction and HPLC method was developed for ketoprofen in skin, fascia and muscle. Tissue samples were homogenized in NaHCO 3. After methylene chloride removal of lipids, the aqueous layer was acidified with HCl and back extracted into isooctane/isopropanol. Ketoprofen was derivatized with ethylchloroformate/S-(−)-α-phenylethylamine in triethylamine, then detected by HPLC. Ketoprofen recovery was linear (1–33 μg/g) and was detected in these tissues following in vivo cathodic iontophoresis (160 mA∗min). This represents the first non-radioactive method for determination of ketoprofen in tissues following transcutaneous iontophoresis.

UV-spectrophotometric determination of ketoprofen and paraben in a gel preparation by partial least-squares calibration

Partial least-squares calibration was used for the simultaneous UV spectrophotometric determination of the active principle (ketoprofen) and preservative (parabens) in a pharmaceutical preparation commercially available in gel form. Calibration mixtures were prepared by mixing pure solutions of the analytes. The analytes were extracted and the UV spectrum of the resulting dispersion was recorded. Suppression of the effect of undissolved gel components was accomplished by prior centrifugation, using first and second-derivative spectra, introducing artificial baseline changes and adding the turbidity effect on the sample spectrum to some of the spectra in the calibration matrix. Both the second-derivative and the addition of the turbidity effect allow the quantification of non-centrifuged samples, the last one seems to be a little more effective. The results thus obtained are compared with those provided by HPLC following centrifugation of the samples.

Macromolecular prodrugs. VI. Kinetic study of poly[α,β-(N-2-hydroxyethyl-DL-aspartamide)]-ketoprofen hydrolysis

The kinetics of hydrolysis of ketoprofen from poly[α,β-( N -2-hydroxyethyl-DL-aspartamide)]-ketoprofen conjugate (PHEA-Ket) in aqueous buffer solutions in the pH range 1.0–10.6 at 37°C was studied. The hydrolysis of PHEA-Ket conjugate followed the pseudofirst-order kinetic. The following rate constants were obtained: k = 1.542 × 10 −2 h −1 at pH = 1.0, k = 6.260 × 10 −3 h −1 at pH = 9.2, and k = 0.155 h −1 at pH = 10.6. At pH = 5.0 and 7.0 no significant hydrolysis was observed. The PHEA-Ket was also stable after exposure to several enzymatic systems in neutral medium. Determination of ketoprofen was performed by high performance liquid chromatography using diclofenac as the internal standard.

Determination of the total concentration of highly protein-bound drugs in plasma by on-line dialysis and column liquid chromatography: application to non-steroidal anti-inflammatory drugs.

The potential of on-line dialysis as a sample preparation procedure for compounds highly bound to plasma proteins is evaluated, using non-steroidal anti-inflammatory drugs as model compounds and column liquid chromatography as the separation technique. Different strategies to reduce the degree of drug-protein binding and so increase the analyte recovery are systematically explored and discussed: alteration of the conformation of the binding protein by changing the pH of the sample or by adding an organic solvent, addition of several displacing compounds and combinations of such approaches. A fully automated method is presented for the determination of ketoprofen, ibuprofen, flurbiprofen, fenoprofen and naproxen in human plasma, in which the absolute analyte recoveries are increased from 0-1% (untreated samples) to 40-65%. Relevant analytical data are given to demonstrate the reliability of the proposed procedure.

The polarographic behaviour of ketoprofen and assay of its capsules using spectrophotometric and voltammetric methods

The quantitative determination of ketoprofen using spectrophotometric and voltammetric methods are described. The spectrophotometric procedure depends upon the reaction of ketoprofen with N-bromosuccinimide (NBS). The residual reagent is then determined by formation of violet colour with 2,2-diphenyl-l-picryl hydrazine (DPPH 2). The consumed NBS would correspond to ketoprofen. Beer's law is valid over the concentration range 5–80 μg/ml of the drug. Direct current (DC) polarography allows to study the reduction behaviour of ketoprofen at the dropping mercury electrode (DME) using different supporting electrolytes at different pH values. Direct current stripping voltammetry (DCSV) was used for the quantitative measurements of the drug. The calibration graph of peak current vs concentration was linear from 0.254 × 10 −2 to 0.254 μg/ml. In model solutions as little as 5.08 × 10 −4 ng/ml ketoprofen can be detected by DCSV. Both methods were applied successfully for the determination of ketoprofen either in pure or dosage forms.

Spectrophotometric determination of ketoprofen in pharmaceutical preparations by means of charge transfer complex formation

A spectrophotometric determination of ketoprofen based upon oxime formation followed by charge transfer complexation with o-chloranil has been developed. Different variables affecting the complexation process have been studied. Beer's law is obeyed in the concentration range 10–80 μg/ml. The method has been successfully applied to the determination of ketoprofen in pure form and in pharmaceutical dosage forms in the presence of its impurities.

Enantiospecific gas chromatographic—mass spectrometric procedure for the determination of ketoprofen and ibuprofen in synovial fluid and plasma: application to protein binding studies

A method for the enantiospecific quantitation of two commonly prescribed non-steroidal anti-inflammatory drugs (ketoprofen and ibuprofen) is described. The method involves formation of a mixed anhydride of the drug with ethylchloroformate and subsequent conversion to an amide by reaction with optically active amphetamine. The subsequently formed diastereomers are separated by gas chromatography—mass spectrometry using selected-ion monitoring. The assay is capable of quantifying ketoprofen (2 ng/ml) and ibuprofen (3 ng/ml) enantiomers from a 200-μl sample of synovial fluid or plasma and is particularly suitable for protein binding studies.

High-Performance Liquid Chromatographic Determination of Ketoprofen in Pharmaceutical Dosage forms and Plasma

Abstract A high-performance liquid chromatographic (HPLC) method for determining ketoprofen in dosage forms and plasma is developed. The drug was chromatographed in a C18 column, using a mobile phase consisting of acetonitrile and 1 % acetic acid aqueous solution with ratio 40 : 60, and detected at 254 nm. The linear detector response to the concentration was confirmed. Recoveries from standard addition to tablets and nonaqueous solution were 100.43 and 100.15, for humans and for rabbit plasmas 82.4 and 82.7, respectively. The procedure showed excellent reproduction inside of two days. It is suggested that this HPLC method could be used for routine assay of ketoprofen in pharmaceutic dosage forms and plasma.

Liquid Chromatographic Determination of Ketoprofen and Its Related Compounds in Raw Materials, Capsules, and Enteric Coated Tablets

Abstract A liquid chromatographic method for the determination of ketoprofen and 6 known related compounds has been developed. The lower limit of quantitation of the related compounds in the drug is 0.05% or less for all compounds, and the precision of the drug assay method is about 1.5%. The highest levels of impurities found in 3 drug raw material samples and 4 solid oral dosage formulations were 1.37 and 0.43%, respectively.

Highly sensitive determination of ketoprofen in human serum and urine and its application to pharmacokinetic study

Highly sensitive determination of ketoprofen in human serum and urine and its application to pharmacokinetic study

Trace analysis of ketoprofen in human serum by electron capture detector gas chromatography

A high sensitive determination of ketoprofen (KP) in the human serum after cutaneous administration of KP was developed by using electron capture detector gas chromatography (GC-ECD). The extracted KP was derivatized with pentafluorobenzyl bromide, and the reactant purified with Sep-Pak C18 cartridge. The KP derivative was separated by high performance liquid chromatographic technique, and determined by using GC-ECD. This procedure provided linear calibration curve ranging 2 to 80 ng/ml and the limit of detection was approximately 0.5 ng/ml in the human serum. This method was applicable to pharmacokinetic studies of this drug.

Electrochemical reduction of ketoprofen and its determination in pharmaceutical dosage forms by differential-pulse polarography.

A simple differential-pulse polarographic method has been developed for the determination of ketoprofen in dosage forms. Methanol was employed as the solvent for extracting the drug from the formulations, and Britton-Robinson buffer (pH 6.0) containing 5%V/V methanol was used as the supporting electrolyte. The EP occurs at – 1.15 V. Results obtained by the proposed method are in excellent agreement with those provided by the manufacturer's laboratory. Commonly used tablet excipients and suppository bases were found not to interfere. A mechanism for the electrochemical reduction of ketoprofen at – 1.25 V is proposed that involves the transfer of two electrons.

Determination of ketoprofen in biological fluids by reversed-phase chromatography

A sensitive and specific high-performance liquid chromatographic method was developed for the determination of ketoprofen [2-(3-benzoylphenyl)propionic acid] in plasma and urine. The method includes an extraction of the drug and the internal standard [2-(4-benzoylphenyl)butyric acid] into ether from acidified plasma. The organic phase is evaporated, and the residue is dissolved in the mobile phase (acetonitrile–0.02 M phosphate buffer, pH 3) (45:55). A 20-μl aliquot is analyzed on a reversed-phase column. The accuracy is within 1.5% for therapeutic concentrations, and the coefficients of variation are 5.5 and 3.4% for 2 and 10 μg/ml, respectively. For the urine assay, the accuracy is within 3%, and the coefficients of variation are 1.9 and 1.7% for 3 and 50 μg/ml, respectively. This method was applied successfully to the determination of ketoprofen in humans for pharmacokinetic studies.

Determination of ketoprofen in plasma by extractive methylation and electron-capture gas chromatography

Determination of ketoprofen in plasma by extractive methylation and electron-capture gas chromatography

High-Performance Liquid Chromatographic Determination of Ketoprofen in Blood and Urine

A rapid, simple determination was developed for ketoprofen in biological fluids using high-performance liquid chromatography. The method requires selective extraction of this antirheumatic medicament and an internal standard with ether from the previously acidified plasma and urine. After evaporation of the ether, the residue is taken up by methanol and analyzed by reversed-phase liquid chromatography with detection at 254nm. A concentration as low as 0.1μg/ml can be determined with a 0.5-ml sample.

Determination of Ketoprofen by Direct Injection of Deproteinized Body Fluids into a High-Pressure Liquid Chromatographic System

A rapid, sensitive, and specific determination of ketoprofen in human and animal deproteinized body fluids by reversed-phase high-pressure liquid chromatography is presented. The acid is detectable in amounts as low as 0.1μg/ml. Limits of error are in the range of ±5.1% of the sample mean.

Determination of ketoprofen in plasma and urine by high-performance liquid chromatography

Determination of ketoprofen in plasma and urine by high-performance liquid chromatography