Determination Of Non-steroidal Anti-inflammatory Drugs Research Articles

Analytical strategy for the confirmatory analysis of the non-steroidal anti-inflammatory drugs firocoxib, propyphenazone, ramifenazone and piroxicam in bovine plasma by liquid chromatography tandem mass spectrometry

A sensitive and selective method for the simultaneous determination of non-steroidal anti-inflammatory drugs in bovine plasma was developed. Confirmatory analysis was carried out by liquid chromatography coupled with an electrospray ionisation tandem mass spectrometer (LC-ESI–MS/MS). Target compounds were acidified in plasma and extracted with acetonitrile. Sodium chloride was added to assist separation of the plasma and acetonitrile mixture. The acetonitrile extract is then subjected to liquid–liquid purification by the addition of hexane. Accuracy of the methods in plasma was between 93 and 102%. The precision of the method for the basic NSAIDs in plasma expressed as % RSD, for the within-laboratory reproducibility was less than 10%. Decision limit (CCα values) and detection capability (CCβ) values were established. The methods were validated according to Commission Decision 2002/657/EC.

Optimization of the derivatization reaction and the solid-phase microextraction conditions using a D-optimal design and three-way calibration in the determination of non-steroidal anti-inflammatory drugs in bovine milk by gas chromatography–mass spectrometry

An experimental design optimization is reported of an analytical procedure used in the simultaneous determination of seven non-steroidal anti-inflammatory drugs (NSAIDs) in bovine milk by gas chromatography with mass spectrometry detection (GC–MS). This analytical procedure involves a solid-phase microextraction (SPME) step and an aqueous derivatization procedure of the NSAIDs to ethyl esters in bovine milk. The following NSAIDs are studied: ibuprofen (IBP), naproxen (NPX), ketoprofen (KPF), diclofenac (DCF), flufenamic acid (FLF), tolfenamic acid (TLF) and meclofenamic acid (MCL). Three kinds of SPME fibers – polyacrylate (PA), polydimethylsiloxane/divinylbenzene (PDMS/DVB) and polydimethylsiloxane (PDMS) – are compared to identify the most suitable one for the extraction process, on the basis of two steps: to determine the equilibrium time of each fiber and to select the fiber that provides the best figures-of-merit values calculated with three-way PARAFAC-based calibration models at the equilibrium time. The best results were obtained with the PDMS fiber. Subsequently, 8 experimental factors (related to the derivatization reaction and the SPME) were optimized by means of a D-optimal design that involves only 14 rather than 512 experiments in the complete factorial design. The responses used in the design are the sample mode loadings of the PARAFAC decomposition which are related to the quantity of each NSAID that is extracted in the experiment. Owing to the fact that each analyte is unequivocally identified in the PARAFAC decomposition, a calibration model is not needed for each experimental condition. The procedure fulfils the performance requirements for a confirmatory method established in European Commission Decision 2002/657/EC.

Electromembrane extraction (EME) and HPLC determination of non-steroidal anti-inflammatory drugs (NSAIDs) in wastewater samples

In this paper, an electromembrane extraction (EME) combined with a HPLC procedure using diode array (DAD) and fluorescence detection (FLD) has been developed for the determination of six widely used non-steroidal anti-inflammatory drugs (NSAIDs): salicylic acid (SAC), ketorolac (KTR), ketoprofen (KTP), naproxen (NAX), diclofenac (DIC) and ibuprofen (IBU). The drugs were extracted from basic aqueous sample solutions, through a supported liquid membrane (SLM) consisting of 1-octanol impregnated in the walls of a S6/2 Accurel® polypropylene hollow fiber, and into a basic aqueous acceptor solution resent inside the lumen of the hollow fiber with a potential difference of 10V applied over the SLM. Extractions that were carried out in 10min using a potential of 10V from pH 12 NaOH aqueous solutions shown concentration enrichments factors of 28–49 in a pH 12 NaOH aqueous acceptor solution. The proposed method was successfully applied to urban wastewaters. Excellent selectivity was demonstrated as no interfering peaks were detected. The procedure allows very low detection and quantitation limits of 0.0009–9.0 and 0.003–11.1μgL−1, respectively.

Simultaneous determination of non-steroidal anti-inflammatory drugs in river water samples by liquid chromatography–tandem mass spectrometry using molecularly imprinted polymers as a pretreatment column

A restricted access media-molecularly imprinted polymer (RAM-MIP) for flufenamic acid has been developed for the simultaneous determination of non-steroidal anti-inflammatory drugs (NSAIDs) in river water samples. The RAM-MIP was prepared using 4-vinylpyridine and ethylene glycol dimethacrylate as a functional monomer and cross-linker, respectively, by a multi-step swelling and polymerization method followed by a surface modification technique. The RAM-MIP for flufenamic acid showed excellent molecular recognition abilities for flufenamic acid and mefenamic acid, and moderate molecular recognition abilities for indomethacin, etodolac and ketoprofen. The simultaneous determination of NSAIDs (mefenamic acid, indomethacin, etodolac and ketoprofen) in river water samples was carried out by LC–MS/MS using the RAM-MIP for flufenamic acid as a pretreatment column. The concentrations of mefenamic acid, indomethacin and etodolac in river water samples were determined to be 0.4, 0.7 and 0.3 ng/L, respectively, while ketoprofen was below the limit of quantitation.

Fluorous derivatization and fluorous-phase separation for fluorometric determination of naproxen and felbinac in human plasma

Fluorous derivatization followed by fluorous-phase liquid chromatographic (LC) separation exploits the affinity between perfluoroalkyl compounds for highly selective and quantitative isolation of various analytes. However, the applicability of this technique as a simple pretreatment for fluorometric determination in clinical settings has not been fully explored. Here we show the applicability of this technique to the clinical determination of non-steroidal anti-inflammatory drugs (NSAIDs) in human plasma. Naproxen and felbinac, widely used native-fluorescent NSAIDs with a carboxyl group, can have toxic effects at acute doses, and were therefore chosen as representative NSAIDs. Samples were precolumn derivatized with a non-fluorescent fluorous amine, which allowed highly selective retention of only derivatized substances in the fluorous LC column. Thus, subsequently, only the retained fluorous-labeled and fluorescent analytes were detected fluorometrically at appropriate retention times. The detection limits for these two drugs were less than 11 fmol on column. Correlation curves were liner over the range of 0.04–10 and 5–250 nmol/mL plasma for both two drugs ( r > 0.999) with good repeatability. Thus, this method offers a simple, sensitive, and selective solution for determination of NSAIDs in clinical settings.

Hollow fiber liquid phase microextraction as a preconcentration and clean-up step after pressurized hot water extraction for the determination of non-steroidal anti-inflammatory drugs in sewage sludge

A method for the quantitative determination of non-steroidal anti-inflammatory drugs (NSAIDs) in sewage sludge was developed and validated. The target compounds were extracted using pressurized hot water extraction (PHWE) and then purified and preconcentrated by three-phase hollow fiber liquid phase microextraction (HF-LPME) followed by LC–ESI-MS analysis. The PHWE was optimized with regard to the pH of solvent as well as other operational parameters. The optimum conditions were 0.01 M NaOH as the extraction solvent, temperature of 120 °C, pressure of 100 bar, static time 5 min, 5 cycles, flush volume 90% and purge time 60 s. Spike recoveries for sludge samples spiked at 200 ng g −1 were in the range of 101–109% but for the native drugs in non-spiked sludge samples, recoveries were 38.9%, 59.8%, 90.3% and 47.8% for ketoprofen, naproxen, diclofenac and ibuprofen, respectively. Donor phase pH, ionic strength and extraction time were optimized for HF-LPME after PHWE. The optimum conditions were 2 h extraction at pH 1.5 without salt addition. Enrichment factors in the range of 947–1213 times were achieved (extraction recoveries were 23.6–30.3%) for HF-LPME after PHWE. The matrix effect on the ionization of drugs in LC–ESI-MS was also investigated. The results show that there is a smaller matrix effect (−8.9% to +14.6%) in comparison with other published values obtained using solid phase extraction (SPE) for clean-up after pressurized liquid extraction (PLE). Method detection limits (MDLs) and method quantification limits (MQLs) for different drugs were in the range of 0.4–3.7 ng g −1 and 1.5–12.2 ng g −1 in dried sludge samples, respectively. The characteristics of the proposed method were compared with those of other published works. The considerably lower ion suppression/enhancement and minimum use of organic solvents (a few microliters of di-n-hexyl ether) in the sample preparation step are two highlighted advantages of the proposed method in comparison with previously published works. The method was applied to determine NSAIDs in sewage sludge from Källby wastewater treatment plant (Lund, Sweden) in April, June, August and October 2010. The highest concentration level was recorded for ibuprofen in the April sewage sludge sample (588 ng g −1) and all of the selected NSAIDs were detected in all the samples analyzed.

Derivatization of carboxylic acids with 4-APEBA for detection by positive-ion LC-ESI–MS(/MS) applied for the analysis of prostanoids and NSAID in urine

In order to develop a generic positive ionization ESI LC–MS method for a variety of interesting substance classes, a new derivatization strategy for carboxylic acids was developed. The carboxylic acid group is labeled with the bromine containing 4-APEBA reagent based on carbodiimide chemistry. The derivatization reaction can be carried out under aqueous conditions, thereby greatly simplifying sample preparation. In this paper, the derivatization of carboxylic acids is exemplified for the determination of prostanoids and non-steroidal anti-inflammatory drugs (NSAID). Optimization of the derivatization conditions was studied. In order to prove the applicability of the presented approach, we applied the described protocol to urine samples from complex regional pain syndrome (CRPS) patients and were able to detect several prostanoids not visible in the urine of healthy volunteers. Further, the determination of the non-steroidal anti-inflammatory drug ibuprofen in a urine sample was possible.

Determination of non-steroidal anti-inflammatory drugs in sewage sludge by direct hollow fiber supported liquid membrane extraction and liquid chromatography–mass spectrometry

In this study, a three-phase hollow fiber liquid-phase microextraction (HF-LPME) method combined with liquid chromatography–mass spectrometry was developed for direct determination of four non-steroidal anti-inflammatory drugs (ketoprofen, naproxen, diclofenac and ibuprofen) in sewage sludge. The drugs were extracted from non-spiked and spiked slurry samples with different amounts of sludge into an organic phase and then back-extracted into an aqueous phase held in the lumen of the hollow fiber. High enrichment factors ranging from 2761 to 3254 in pure water were achieved. In sludge samples, repeatability and inter-day precision were tested with relative standard deviation values between 10–18% and 7–15%, respectively. Average concentrations of 29 ± 9, 138 ± 2, 39 ± 5 and 122 ± 7 ng/g were determined in dried sludge from Källby sewage treatment plant (Sweden) for ketoprofen, naproxen, diclofenac and ibuprofen, respectively .

Analytical strategy for the determination of non-steroidal anti-inflammatory drugs in plasma and improved analytical strategy for the determination of authorised and non-authorised non-steroidal anti-inflammatory drugs in milk by LC–MS/MS

A sensitive and selective method for the determination of six non-steroidal anti-inflammatory drugs (NSAIDs) in bovine plasma was developed. An improved method for the determination of authorised and non-authorised residues of 10 non-steroidal anti-inflammatory drugs in milk was developed. Analytes were separated and acquired by high performance liquid chromatography coupled with an electrospray ionisation tandem mass spectrometer (ESI–MS/MS). Target compounds were acidified in plasma, and plasma and milk samples were extracted with acetonitrile and both extracts were purified on an improved solid phase extraction procedure utilising Evolute™ ABN cartridges. The accuracy of the methods for milk and plasma was between 73 and 109%. The precision of the method for authorised and non-authorised NSAIDs in milk and plasma expressed as % RSD, for the within lab reproducibility was less than 16%. The % RSD for authorised NSAIDs at their associated MRL(s) in milk was less than 10% for meloxicam, flunixin and tolfenamic acid and was less than 25% for hydroxy flunixin. The methods were validated according to Commission Decision 2002/657/EC.

Determination of nonsteroidal anti-inflammatory drugs in human plasma by LC-MS-MS with a hydrophilic polymer column

Six nonsteroidal anti-inflammatory drugs (NSAIDs) in human plasma samples were analyzed by liquid chromatography (LC)-electrospray ionizationtandem mass spectrometry (MS-MS) using a hydrophilic polymer column (MSpak GF-310 4B), which enabled direct injection of crude biological samples. Separation of the six NSAIDs, alminoprofen, flurbiprofen, ibuprofen, pranoprofen, tiaprofenic acid, and zaltoprofen, was carried out using gradient elution with 10 mM ammonium acetate/acetonitrile. The mass spectra obtained by LC-single stage MS showed base peak ions due to [M+H]+ for alminoprofen, zaltoprofen, tiaprofenic acid, and pranoprofen, and [M-H]- for ibuprofen and flurbiprofen. Product ions were produced from each [M+H]+ or [M-H]- ion in the tandem mode. Quantitation was performed by multiple reaction monitoring with switching from positive to negative ion mode and vice versa. All drugs spiked into plasma showed recoveries of 77.0%–88.2%. The regression equations for the six drugs showed excellent linearity in the range of 0.01–25 μg/ml of plasma, and limits of detection were in the range of 0.002–0.005 μg/ml. Limits of quantitation were 0.01–0.02 μg/ml. Intraday and interday coeffi cients of variation for all drugs in plasma were not greater than 8.1%. The accuracy of quantitating the six drugs was in the range of 94.5%–110%. Data obtained from actual determinations of the levels of alminoprofen, pranoprofen, and ibuprofen in human plasma after oral administration are also presented.

Thin-layer Chromatography Methods for the Determination of Non- Steroidal Anti-inflammatory Drugs and Cephalosporin Antibiotics: A Review

An extensive survey of the literature published in analytical and pharmaceutical chemistry journals has been conducted and the TLC methods which were developed and used for determination of non-steroidal anti-inflammatory drugs (NSAIDs) and cephalosporin antibiotics in bulk drugs, formulations and biological fluids have been reviewed. This review covers the time period from 1990 to 2008 during which over 120 TLC methods were reported. Presented review highlighted some recent patent developments and new TLC techniques that have been used in the analysis and detection of two different kinds of drugs. Keywords: TLC, NSAIDs, cephalosporins, analytical methods, review

Determination of non-steroidal anti-inflammatory drugs in wastewaters by magnetic matrix solid phase dispersion–HPLC

A series of supports functionalized with different alkyl chains and covered with magnetite were synthesized, characterized and applied in the sample pre-concentration of four non-steroidal anti-inflammatory drugs (acetaminophen, naproxen, diclofenac and ibuprofen) contained in wastewater samples. The general methodology involved magnetic solid phase dispersion followed by the analysis by high-performance liquid chromatography with ultraviolet detection. The magnetic supports were initially dispersed in the samples with the aid of Triton X-100, then supports were magnetically isolated and the analytes were eluted with methanol. Finally the extract was injected into the HPLC system. The highest recovery percentage (>90%) was obtained with the support containing octyl chains (C8) at pH 3. The lowest limits of detection achieved ranged within 1–2 μg L −1 with repeatability (expressed as RSD) below 5% in all cases. The method was applied in the analysis of wastewater samples.

One-step in-syringe ionic liquid-based dispersive liquid–liquid microextraction

Dispersive liquid–liquid microextraction (DLLME) has been proved to be a powerful tool for the rapid sample treatment of liquid samples providing at the same time high enrichment factors and extraction recoveries. A new, simple and easy to handle one step in-syringe set-up for DLLME is presented and critically discussed in this paper. The novel approach avoids the centrifugation step, typically off-line and time consuming, opening-up a new horizon on DLLME automation. The suitability of the proposal is evaluated by means of the determination of non-steroidal anti-inflammatory drugs in urine by liquid chromatography/ultraviolet detection. In the presented approach an ionic liquid is used as extractant. The target drugs can be determined in urine within the concentration range 0.02–10 μg mL −1, allowing their determination at therapeutic and toxic levels. Limits of detection were in the range from 8.3 ng mL −1 (indomethacin) to 32 ng mL −1 (ketoprofen). The repeatability of the proposed method expressed as RSD ( n = 5) varied between 2.5% (for ketoprofen) and 8.6% (for indomethacin).

Determination of widely used non-steroidal anti-inflammatory drugs in water samples by in situ derivatization, continuous hollow fiber liquid-phase microextraction and gas chromatography-flame ionization detector

The aim of this study was to develop an analytical procedure which allows the quantification of pharmaceuticals in water at the ng L −1 level. Hence, it is reported research on the application of a rapid, inexpensive and simple continuous hollow fiber liquid-phase micro extraction (CHF-LPME) for the pre-concentration and determination of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (IBP), naproxen (NAP), and ketoprofen (KEP), in wastewater. In this method, a 2.50 cm end sealed piece of a polypropylene hollow fiber was immersed into the organic solvent, octanol, for 30 s. After solvent impregnation with the pores of the fiber, the excess amounts of solvent were removed from inside the fiber, and 4.0 μL of octanol, as the acceptor phase, was injected into the fiber carefully. The fiber was settled using a microsyringe into a 10.0 mL glass test tube, and 20.00 mL of the aqueous solution (the donor phase), was circulated by a pump around it. After analyte extraction for an optimized period of time (20 min), 2 μL of the organic solvent was withdrawn into the microsyringe and injected into the GC-FID for further analysis. Finally, based on the optimized analytical conditions, the method was linear in the range of 2.5–500 ng L −1. The limits of detection were 1–2 ng L −1. Repeatability of this method on an intra-day scale was 3.4–10.2% (RSD%). NSAIDs have been detected in several municipal wastewater samples, and the concentration range was 9.0–19.0 ng L −1.

Counter-flow electrokinetic supercharging for the determination of non-steroidal anti-inflammatory drugs in water samples

Electrokinetic supercharging (EKS) has been used in the last few years as a powerful tool for separation and on-line preconcentration of different types of analytes. We have developed a valuable modification for EKS system, namely counter-flow EKS (CF-EKS) and applied it for the separation and on-line preconcentration of seven non-steroidal anti-inflammatory drugs (NSAIDs) in water samples. In CF-EKS, a hydrodynamic counter-flow is applied during electrokinetic injection of the analytes within the EKS system. This counter-flow minimises the introduction of the sample matrix into the capillary, allowing longer injections to be performed. Careful choice of the optimum counter-flow as well as the optimum injection voltage allowed the sensitivity to be enhanced by 11,800-fold, giving limits of detection (LODs) of 10.7–47.0 ng/L for the selected NSAIDs. The developed method was validated and then applied for the determination of the studied NSAIDs in drinking water as well as wastewater samples from Hobart city.

In‐line liquid‐phase microextraction for selective enrichment and direct electrophoretic analysis of acidic drugs

This work describes an efficient in-line extraction-preconcentration unit coupled to the electrophoretic capillary based on a liquid-phase microextraction (LPME) process, which can be directly assembled to the cartridge of the commercial CE equipment. The unit permits analyte extraction, preconcentration and electrophoretic separation to be automatically performed in the commercial CE equipment without the need for additional hardware or software. This new approach was usefully used for the separation and determination of nonsteroidal anti-inflammatory drugs in human urine permitting at least to analyze 30 consecutive real samples. The LODs were lower than 2 microg/L and the reproducibility, expressed as RSD, was 3.1% for the same unit and only 4.8% between different units.

Determination of non-steroidal anti-inflammatory drugs in pharmaceuticals and human serum by dual-mode gradient HPLC and fluorescence detection

Non-steroidal anti-inflammatory drugs (NSAIDs) such as piroxicam and mefenamic acid are commonly prescribed to treat inflammation, pain and fever. Similarly acetylsalicylic acid is used to prevent strokes and heart attacks. A rapid and selective method was developed for the simultaneous assay of three NSAIDs and salicylic acid via HPLC with fluorescence detection. The separation was performed using a “dual-mode” gradient (acetonitrile–0.1% aqueous orthophosphoric acid) and the analysis was completed within 7 min using an ACE ® column C18, 5 μm, 150 mm × 4.6 mm. Naproxen was used as internal standard. The proposed method is simple, selective as well as with a good sensitivity reaching LOD lower than 2 pmol (0.05 μM) and was applied for quantitative analysis in pharmaceuticals and in human serum samples. The mean recovery was more than 95% and the within-day and between-days precisions were found to be satisfactory having RSD within the acceptable limits (<10%).

Complex compounds of terbium(III) with some nonsteroidal anti-inflammatory drugs and their analytical applications

Luminescence properties of the complexes of terbium(III) with nonsteroidal anti-inflammatory drugs (ibuprofen and orthofen) were studied. It was demonstrated that in the presence of organic bases (2,2’-dipyridyl and 1,10-phenanthroline) mixed-ligand complexes are formed and the luminescence intensity of terbium(III) increases by a factor of up to 250. The optimum complexation conditions were determined. It was proposed to use these complexes as analytical forms for the luminescence determination of nonsteroidal anti-inflammatory drugs (ibuprofen and orthofen) in pharmaceutical dosage forms. The detection limits are 2 and 0.05 μg/mL, respectively.

Determination of non-steroidal anti-inflammatory drugs in urine by combining an immobilized carboxylated carbon nanotubes minicolumn for solid-phase extraction with capillary electrophoresis-mass spectrometry

Last years, the usefulness of the use of carbon nanotubes (CNTs) as sorbent material have been demonstrated for a wide variety of compounds. In this work, it has been demonstrated for first time that immobilized carboxylated single-walled carbon nanotubes (c-SWNTs) offer clear advantages over the use of CNTs. The higher adsorption capacity has been attributed to the special orientation of c-SWNTs molecules on the glass surface. The potential of this new sorbent was evaluated for the preconcentration of non-steroidal anti-inflammatory drugs (NSAIDs) from urine samples. Purified samples were analysed by capillary electrophoresis-mass spectrometry detection allowing the determination of 1.6 to 2.6 μg/L of NSAIDs with only 5 mL of sample. The precision of the method for the determination of real spiked urine samples ranged from 5.4 to 7.4% and the recoveries from 98.6 to 102.2%.

Determination of non-steroidal anti-inflammatory drugs in environmental samples by chromatographic and electrophoretic techniques

Non-steroidal anti-inflammatory drugs (NSAIDs) are a group of pharmaceutical compounds widely used in human health care and often found in the aquatic environment, with their metabolites. After an introduction that describes the general problem of drug contamination, the properties of NSAIDs, and environmental risk assessment, this review surveys the chromatographic and electrophoretic methods of analysis in use today for monitoring the most important representatives of this pharmaceutical class in different environmental samples.