Occurrence, toxicity, impact and removal of selected non-steroidal anti-inflammatory drugs (NSAIDs): A review

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used pharmaceuticals for human therapy, pet therapeutics, and veterinary feeds, enabling them to enter into water sources such as wastewater, soil and sediment, and seawater. The control of NSAIDs has led to the advent of the novel materials for treatment techniques. Herein, we review the occurrence, impact and toxicity of NSAIDs against aquatic microorganisms, plants and humans. Typical NSAIDs, e.g., ibuprofen, ketoprofen, diclofenac, naproxen and aspirin were detected at high concentrations in wastewater up to 2,747,000 ng L-1. NSAIDs in water could cause genotoxicity, endocrine disruption, locomotive disorders, body deformations, organs damage, and photosynthetic corruption. Considering treatment methods, among adsorbents for removal of NSAIDs from water, metal-organic frameworks (10.7-638 mg g-1) and advanced porous carbons (7.4-400 mg g-1) were the most robust. Therefore, these carbon-based adsorbents showed promise in efficiency for the treatment of NSAIDs.

Literature Review: Evaluation of Drug Removal Techniques in Municipal and Hospital Wastewater

There are several techniques for the removal of pharmaceuticals (drugs) from wastewater; however, strengths and weaknesses have been observed in their elimination processes that limit their applicability. Therefore, we aimed to evaluate the best techniques for the removal of pharmaceuticals from municipal and hospital wastewater. For this, a non-experimental, descriptive, qualitative-quantitative design was used, corresponding to a systematic review without meta-analysis. Based on established inclusion and exclusion criteria, 31 open-access articles were selected from the Scopus, ProQuest, EBSCOhost, and ScienceDirect databases. The results showed that high concentrations of analgesics such as naproxen (1.37 mg/L) and antibiotics such as norfloxacin (0.561 mg/L) are frequently found in wastewater and that techniques such as reverse osmosis, ozonation, and activated sludge have the best removal efficiency, achieving values of 99%. It was concluded that reverse osmosis is one of the most efficient techniques for eliminating ofloxacin, sulfamethoxazole, carbamazepine, and diclofenac from municipal wastewater, with removal rates ranging from 96 to 99.9%, while for hospital wastewater the activated sludge technique proved to be efficient, eliminating analgesics and antibiotics in the range of 41-99%.

Effective adsorption of diclofenac and naproxen from water using fixed-bed column loaded with composite of heavy sugarcane ash and polyethylene terephthalate

The contamination of water by pharmaceutical pollutants is a major issue these days due to excessive use of these ingredients in modern life. This study evaluated the adsorption and effectiveness of a low-cost composite prepared from heavy sugarcane ash (HSA) fused with polyethylene terephthalate (PET) and functionalized with iron (Fe³⁺) in a dynamic system through a fixed-bed column. The solution of synthetic drugs was prepared and placed in a reservoir, using a peristaltic pump the solution is run onto the fixed bed column at a flow rate of 2 mL min^-1. Saturation time and adsorption capacity were evaluated by centrifugation and extraction after a regular interval of 2 h from the adsorption column. The samples were analyzed using high-performance liquid chromatography (HPLC) and the data was modeled for quantification. For DIC removal, an adsorption capacity of 324.34 μg. g^-1 and a saturation time of 22 h were observed, while the adsorption capacity of NAP was 956.49 μg. g^-1, with a saturation time of 8 h. Thus, the PETSCA/Fe³⁺ adsorbent proved to be quite efficient for removing the pharmaceutical pollutants, with a longer period of operation for DIC removal. These findings suggested that a highly efficient bed column made from a less expensive waste material and could be used to remove hazardous pharmaceutical contaminants.

From the pills to environment - Prediction and tracking of non-steroidal anti-inflammatory drug concentrations in wastewater

The extend of environment pollution by pharmaceuticals is in a stage that required more automatic and integrated solutions. The non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most popular pharmaceutical in the world and emerging pollutants of natural waters. The aim of the paper was to check the correlation of the sales data of selected NSAIDs (ibuprofen, naproxen, diclofenac) and their concentration in the WWTP in order to enable predicting their loads, having only the sales data. For calculations, we apply three discharge scenarios (the fates between purchased to the presence in influents), having in mind that some part of sold mass can be improperly dispose to sewage system. To support predictions, chemical analysis was conducted in two conventional wastewater treatment plants (WWTPs) located in Poland during 2018 and 2020, thereby before and during pandemic situation. The NSAIDs concentration in the influent was higher than that which would be obtained if all of the administrated mass of the pharmaceutical went through the metabolic pathway of transformation. This means that substantial mass of sold NSAIDs in improperly dispose to sewage system, and this factor need to be taken into account in future predictions. Furthermore, results indicate that the variance of naproxen and diclofenac concentrations in the influent has no correlation with relatively stable sales throughout whole year. The pandemic situation had yet no direct effect to diclofenac concentrations in influents, despite observed increasing of sales. It was calculated that more than 60 kg of diclofenac was discharged into the Baltic Sea in 2018, and 20 kg in the first half of 2021 from two tested WWTPs. The presence of 4OH-diclofenac in effluents often in higher concentration compared to diclofenac mean that this still biologically active compound need to be taken into account in future risk assessment.

Design and application of molecularly imprinted polymers for adsorption and environmental assessment of anti-inflammatory drugs in wastewater samples

In this study, a series of molecularly imprinted polymers (MIPs) have been synthesized using separately diclofenac, naproxen, and ibuprofen as templates with three different polymerization approaches. Two functional monomers, methacrylic acid (MAA) and 2-vinylpyridine (2-VP), were tested and ethylene glycol dimethacrylate (EGDMA) was used as crosslinker; also, template-free polymers (NIPs) were synthesized. It was found that the MIP with the highest retention percentage for diclofenac was the one prepared by the emulsion approach and with MAA (98.3%); for naproxen, the one prepared by the bulk polymerization with MAA (99%); and for ibuprofen, the one synthesized by bulk with 2-VP (97.7%). These three MIPs were characterized by scanning electron microscopy, thermogravimetric test, Fourier transform infrared, specific area measurements, and surface charge. It was found that the emulsion method allowed particle size control, while the bulk method gave heterogeneous particles. The three evaluated MIPs exhibited thermal stability up to 300 °C, and it was observed that 2-VP confers greater stability to the material. From the BET analysis, it was demonstrated that the MIPs and NIPs evaluated are mesoporous materials with a pore size between 10 and 20 nm. In addition, the monomer influenced the surface charge of the material, since the MAA conferred an acidic point of zero charge (PZC), while the 2-VP conferred a PZC of basic character. Through adsorption isotherms, it was determined  that there is a higher adsorption capacity of the MIPs at acidic pH following a pseudo-second-order kinetic model. Finally, the MIPs were used to determine the non-steroidal anti-inflammatory drugs (NSAIDs) understudy in San Luis Potosí, México, wastewater, finding concentrations of 0.642, 0.985, and 0.403 mg L^-1 for DCF, NPX, and IBP, respectively.

Pharmaceuticals as emerging pollutants: Case naproxen an overview

Nonsteroidal anti-inflammatory drugs (NSAIDs), including naproxen (NP), diclofenac, ibuprofen, etc., are widely used for fever and pain relief. NP is one of the most widely consumed drugs in the world, because it is available over the counter in many countries. Many studies have proven that NP is not eliminated in conventional water treatment processes and its biodegradation in the environment is also difficult compared to other drugs. Along these lines, we are aware that both the original compound and its metabolites can be found in different destinations in the environment. To assess the environmental exposure and the risks associated with NP, it is important to understand better the environment where they finally reach, the behavior of its original compounds, its metabolites, and its transformation products. In this sense, the purpose of this review is to summarize the current state of knowledge about the introduction and behavior of NP in the environments they reach and highlight research needs and gaps. Likewise, we present the sources, environmental destinations, toxicology, environmental effects, and quantification methodologies.

Occurrence and ecotoxicological risk assessment of non-steroidal anti-inflammatory drugs in South African aquatic environment: What is known and the missing information?

Non-steroidal anti-inflammatory drugs (NSAIDs) are medications used individually or as mixtures with other pharmaceuticals for the treatment of various illnesses. Their easy accessibility and high human consumption have resulted to their detection at high concentrations in South African water resources. In the present work, an extensive review of the occurrence and ecotoxicological risk assessment of NSAIDs in South African aquatic environment is provided. Reviewed literature suggested ibuprofen, naproxen, diclofenac, ketoprofen and fenoprofen as the most prominent NSAIDs in the South African aquatic environment. Among these NSAIDs, higher concentrations of ibuprofen are common in South African waters. As a result, this drug was found to pose high ecotoxicological risks towards the aquatic organisms with the highest risk quotients of 14.9 and 11.9 found for algae in surface water and wastewater, respectively. Like in other parts of the world, NSAIDs are not completely removed in wastewater treatment plants. Removal efficiencies below 0% due to higher concentrations of NSAIDs in wastewater effluents rather than influents were observed in certain instances. The detection of NSAIDs in sediments and aquatic plants could serve as the important starting step to investigate other means of NSAIDs removal from water. In conclusion, recommendations regarding future studies that could paint a clearer picture regarding the occurrence and ecotoxicological risks posed by NSAIDs in South African aquatic environment are provided.

UV-visible photodegradation of naproxen in water - Structural elucidation of photoproducts and potential toxicity

The UV-visible photodegradation of Naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid, CAS: 22204-53-1), one of the most used and detected non-steroidal anti-inflammatory drugs (NSAIDs) in the world, and its ecotoxicological consequences were investigated in an aqueous medium. The photo-transformation products were analyzed and the structures of photoproducts were elucidated using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and high-performance liquid chromatography coupled with ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (LC-FTICR-MS). Seven photoproducts were detected and characterized, photo-transformation mechanisms have been postulated to rationalize their formation under irradiation. In silico Q.S.A.R. (Quantitative Structure-Activity Relationship) toxicity predictions were performed with the Toxicity Estimation Software Tool (T.E.S.T.) and in vitro assays were carried out on Vibrio fischeri bacteria. Some of the obtained photoproducts exhibit higher potential toxicity than Naproxen itself but the whole toxicity of the irradiated solution is not of major concern.

Electrochemical analysis of naproxen in water using poly(l-serine)-modified glassy carbon electrode

A poly(l-serine)-modified glassy carbon electrode (PLS/GCE) was fabricated by electropolymerization and used to study the detection of naproxen (NPX), a representative non-steroidal anti-inflammatory drug, in phosphate buffer supporting electrolyte at pH 5.0. Results indicated that the PLS/GCE was capable of determination of NPX at a working potential of 0.92 (vs. Ag/AgCl) in voltammetry mode. Experimental factors such as scan rate, accumulation time, solution pH, initial NPX concentration, and interferences were optimized for NPX determination efficiency. The morphology and elemental distribution of the electrode surface were characterized by ESEM, TEM, PSD, XRD, FTIR, TGA, XPS, and zeta potential. NPX oxidation current increased with increasing analyte concentration and scan rate but decreased with increasing pH. Linear sweep voltammetry calibration curve was established in the NPX concentration range of 4.3-65 μM, with detection limit and average recovery of 0.69 μM (n = 3) and 104 ± 2.5%, respectively. PLS/GCE is simple, accurate, reproducible, and easy for operation, therefore would be cost-effective for the determination of NPX.

Optimization and application of hollow fiber liquid-phase microextraction and microwave-assisted extraction for the analysis of non-steroidal anti-inflammatory drugs in aqueous and plant samples

Human consumption of non-steroidal anti-inflammatory drugs (NSAIDs) is increasing, which poses a great risk of pollution by these pharmaceuticals on the aquatic environment. Therefore, this study reports the optimization of microwave-assisted extraction using water as a green solvent and hollow fiber liquid-phase microextraction (HF-LPME) methods followed by high-performance liquid chromatography-high resolution mass spectrometry analysis of NSAIDs in wastewater and aquatic plant, Eichhornia crassipes. The optimized MAE resulted in efficient transfer of selected NSAIDs from plant samples into the aqueous phase yielding the recoveries ranging from 91 to115%. A multivariate approach based on half fractional factorial and central composite design was used during the optimization of HF-LPME. Under the optimized conditions, the maximum enrichment factors for naproxen, fenoprofen, diclofenac, and ibuprofen were 49, 126, 93 and 156, respectively. The overall analytical method recoveries ranged from 86 to 116% while the limits of quantitation for wastewater and plant samples ranged from 0.09 to 0.59 μg L^-1 and from 0.11 to 0.59 μg kg^-1, respectively. The precision of the proposed analytical method which was measured in terms of RSD values did not exceed 5%. Naproxen was the most abundant compound in both wastewater and the Eichhornia crassipes plant samples with concentrations of up to 3.30 μg L^-1 and 10.97 μg kg^-1, respectively. The detection of NSAIDs in Eichhornia crassipes means this plant has the ability to bioaccumulate pharmaceutical load in surface water.

Effects of chronic exposure to a pharmaceutical mixture on the three-spined stickleback (gasterosteus aculeatus) population dynamics in lotic mesocosms

Pharmaceutical substances are ubiquitous in the aquatic environment and their concentration levels typically range from ng/L up to several μg/L. Furthermore, as those compounds are designed to be highly biologically active, assessing their impacts on non-target organisms is important. Here, we conducted a mesocosm experiment testing a mixture of five pharmaceuticals (diclofenac, carbamazepine, irbesartan, acetaminophen and naproxen) on fish, three-spined stickleback (Gasterosteus aculeatus). The mixture concentration levels were chosen on the basis of the contamination of the Meuse river in Belgium which had been measured previously during a monitoring campaign undertaken in 2015 and 2016. Three nominal mixture concentration levels were tested: the lowest concentration level mixture was composed by environmentally-relevant concentrations that approximate average realistic values for each pharmaceuticals (Mx1); the two other levels were 10 and 100 times these concentrations. Although no impact on stickleback prey was observed, the mixture significantly impaired the survival of female fish introduced in the mesocosms at the highest treatment level without causing other major differences on fish population structure. Impacts on condition factors of adults and juveniles were also observed at both individual and population levels. Using a modelling approach with an individual-based model coupled to a bioenergetic model (DEB-IBM), we concluded that chronic exposure to environmentally-relevant concentrations of five pharmaceuticals often detected in the rivers did not appear to strongly affect the three-spined stickleback populations. Mechanisms of population regulation may have counteracted the mixture impacts in the mesocosms.

Chiral molecularly imprinted polymeric stir bar sorptive extraction for naproxen enantiomer detection in PPCPs

Chiral micropollutant analysis in pharmaceuticals and personal care products (PPCPs) is interesting but challenging. We firstly developed a series of chiral molecularly imprinted polymeric (CMIP) stir bar sorptive extraction coatings by combining a chiral template with chiral functional monomers via a click reaction for naproxen enantiomer analysis in PPCPs. Heterochiral selectivity was observed in the molecule recognition of the CMIP coatings, which demonstrated good adsorption capability for the chiral template and its structurally similar chiral compounds. The coatings also exhibited excellent enrichment capability for chiral analytes in an aqueous matrix. The surface morphology and pore structure of the CMIP coatings were characterized. The molecular interactions between the chiral template and chiral functional monomer were investigated through UV-vis spectroscopy and theoretical calculations to prove the effective interactions existing in the heterochiral MIPs. The CMIP coatings were used to enrich naproxen enantiomers in chiral drug and environmental water samples, and satisfactory recoveries (83.98 %-118.88 %) with a relative standard deviation of 3.49 %-13.08 % were achieved. The heterochiral imprinted coating-based method provided a sensitive, selective, and effective enrichment strategy for chiral micropollutant analysis in PPCPs. This technique is critical for chiral molecule recognition and enantiomer analysis in complex samples.

Naproxen in the environment: its occurrence, toxicity to nontarget organisms and biodegradation

This article summarizes the current knowledge about the presence of naproxen in the environment, its toxicity to nontarget organisms and the microbial degradation of this drug. Currently, naproxen has been detected in all types of water, including drinking water and groundwater. The concentrations that have been observed ranged from ng/L to μg/L. These concentrations, although low, may have a negative effect of long-term exposure on nontarget organisms, especially when naproxen is mixed with other drugs. The biological decomposition of naproxen is performed by fungi, algae and bacteria, but the only well-described pathway for its complete degradation is the degradation of naproxen by Bacillus thuringiensis B1(2015b). The key intermediates that appear during the degradation of naproxen by this strain are O-desmethylnaproxen and salicylate. This latter is then cleaved by 1,2-salicylate dioxygenase or is hydroxylated to gentisate or catechol. These intermediates can be cleaved by the appropriate dioxygenases, and the resulting products are incorporated into the central metabolism. KEY POINTS: •High consumption of naproxen is reflected in its presence in the environment. •Prolonged exposure of nontargeted organisms to naproxen can cause adverse effects. •Naproxen biodegradation occurs mainly through desmethylnaproxen as a key intermediate.

Biological removal of pharmaceuticals by Navicula sp. and biotransformation of bezafibrate

Pharmaceutically active compounds are of great concern due to their detection frequency in the environment and the unexpected risks. In this study, the simultaneous removal of mixed pharmaceuticals by microalgae was explored using a typical freshwater diatom Navicula sp. Results showed that Navicula sp. could efficiently remove atenolol, carbamazepine, ibuprofen and naproxen with the efficiencies of >90% after 21 d of exposure. As compared to the removal efficiencies of each pharmaceutical in the individual pharmaceutical treatments, the degradation of sulfamethoxazole, bezafibrate, and naproxen was improved in the mixed treatment, whereas the removal efficiencies of carbamazepine and atenolol decreased. Additionally, the presence of hydrophobic pharmaceuticals (i.e., ibuprofen and naproxen) accelerated the degradation of carbamazepine and sulfamethoxazole and inhibited the removal of atenolol in the mixture with the combination of six pharmaceuticals, while the addition of other pharmaceuticals show no significant effect on the removal of ibuprofen and naproxen. The bioaccumulation of pharmaceuticals in Navicula sp. increased as their log K_OW values decreased. Four bezafibrate metabolites were identified and the degradation pathways of bezafibrate in diatom were proposed. It is the first report on the metabolism of BEZ in diatom, and further studies on the environmental risk of the metabolites should be investigated.

Removal of trace naproxen from aqueous solution using a laboratory-scale reactive flow-through membrane electrode

The kinetics and mechanisms of naproxen (NPX) degradation with the concentration of 20-200 μg/L were investigated by using reactive flow-through membrane anode. The electrochemical degradation of NPX followed pseudo-first-order reaction kinetics. The kinetic rate constant (k) of 0.649 min^-1 and energy consumption (E_EO) of 0.744 Wh/L were found under optimal conditions with the initial NPX concentration of 50 μg/L. Higher current density benefited •OH production and NPX degradation. Faster rotational speed of pump and lower pH were in favor of electrochemical degradation of NPX, in which k and E_EO were 3.9 and 0.27 times when rotational speed was increased from 100 to 600 rpm, and 4.9 and 0.21 times when pH was decreased from 11.0 to 3.0, respectively. The degradation efficiency and energy consumption were both maintained at a narrow range when the initial concentration of NPX was changed from 20 to 200 μg/L, and even under the addition of humic acid (1.0-10.0 mg/L). The major degradation pathways of NPX were demethylation and decarboxylation, followed with the further ring cleavage reactions. The flow-through membrane electrode is proved to be effective for the elimination of trace NPX from aqueous solution.

Degradation of naproxen in chlorination and UV/chlorine processes: kinetics and degradation products

Naproxen (NAP) is a nonsteroidal anti-inflammatory drug which has been widely used and frequently detected in water environments. This study investigated the NAP degradation in the chlorination and UV/chlorine disinfection processes, which usually acted as the last barriers for water treatment. The results showed that both chlorination and UV/chlorine disinfection could remove NAP effectively. At various chlorine dosages (0.1~0.5 mM), the contributions of chlorination and reactive radicals to the degradation of NAP in the UV/chlorine process were calculated to be 50.5~56.9% and 43.1~49.5%, respectively. However, the reactive radicals dominated in NAP degradation in alkaline solutions, while chlorination dominated in acidic conditions. The HCO₃^- (10~50 mM) slightly inhibited, Cl^- (10~50 mM) gradually promoted, and HA (1~5 mg/L) significantly reduced NAP degradation by UV/chlorine process. The degradation intermediates and products were obtained via high-performance liquid chromatography with QE-MS/MS; NAP was degraded by demethylation, acetylation, and dicarboxylic acid pathways during the chlorination and UV/chlorination processes.

Distribution and ecological risk of pharmaceuticals in surface water of the Yeongsan river, Republic of Korea

This study examined the distribution of pharmaceuticals in Yeongsan River and at point sources (PSs) in the associated water system, and performed a risk assessment based on our findings. The samples included effluents collected from three sewage treatment plants (PS1, PS2, and PS3) and two industrial complexes (PS4 and PS5) as well as surface water collected from seven mainstreams and 11 tributaries of the river. The target pharmaceuticals were acetylsalicylic acid, carbamazepine, clarithromycin, naproxen, sulfamethazine, sulfamethoxazole, sulfathiazole, and trimethoprim, which were detected by liquid chromatography-tandem mass spectrometry. All pharmaceuticals except acetylsalicylic acid and sulfathiazole were found in PS1, PS2, and PS3 samples, whereas acetylsalicylic acid, carbamazepine, sulfamethazine, and sulfamethoxazole were found in PS4, most of the pharmaceuticals were not present in PS5. The rank order of pharmaceutical concentration in surface water was carbamazepine (97.2%, 0.2067 μg/L) > sulfamethoxazole (88.9%, 0.1132 μg/L) > naproxen (51.4%, 0.0516 μg/L) > clarithromycin (43.1%, 0.0427 μg/L). The distribution of pharmaceuticals in the Yeongsan River at PSs and non-PSs differed, and higher concentrations of human pharmaceuticals were detected in upstream and midstream areas whereas higher concentrations of animal pharmaceuticals were found downstream. Hazard quotients (HQs) evaluated at each sites based on mean concentration and 95% upper confidence limits (95% UCLs) were all less than one, indicating a low risk of toxicity. The findings of this study are expected to be useful for risk assessment of aquatic ecosystems.

Pharmaceuticals and Personal Care Products Can Be Transformed by Anaerobic Microbiomes in the Environment and in Waste-Treatment Processes

Pharmaceuticals and personal care products (PPCPs) are emerging environmental contaminants that can be transformed by anaerobic microorganisms in anoxic environments. The present study examined 2 consortia, enriched under methanogenic and sulfate-rich conditions, that demethylate the phenylmethyl ether anti-inflammatory drug naproxen to 6-O-desmethylnaproxen. Both enriched consortia were also able to demethylate a range of phenylmethyl ether compounds of plant-based origin or used as PPCPs. Results from 16S rRNA gene sequencing showed that the 2 communities were very different despite sharing the same PPCP metabolism. In most cases, the demethylated metabolite was not further degraded but rather accumulated in the culture medium. For the expectorant guaifenesin, this resulted in a novel microbial metabolite. Furthermore, to our knowledge, this is the first report of methylparaben metabolism under methanogenic conditions. The wide range of phenylmethyl ether substrates that underwent O-demethylation in both methanogenic and sulfate-rich conditions suggests that there are potentially bioactive transformation products in the environment that have not yet been quantified. Environ Toxicol Chem 2019;38:1585-1593. © 2019 SETAC.

Simultaneous enantiomeric analysis of non-steroidal anti-inflammatory drugs in environment by chiral LC-MS/MS: A pilot study in Beijing, China

A simple, sensitive and quick method for direct simultaneous chiral analysis of frequently used non-steroidal anti-inflammatory drugs (NSAIDs) (ibuprofen, naproxen and flurbiprofen) in river water by HPLC-MS/MS was established and validated. Chromatographic parameters including the mobile phase composition, pH values, temperature and flow rates were optimized to obtain both satisfactory sensitivity and enantiomeric resolution (Rs≥ 1.0), which suggested the composition and pH values of mobile phase played crucial influence on enantioseparations. The method demonstrated its superiority compared with previous studies regarding to the low MQLs (1.1-37.1 ng/L) and short runtime (< 20 min), enabling quantitative enantiomeric determination of trace level of emerging contaminants in water. The environmental monitoring of receiving water (34 sites along rivers) in Beijing revealed ibuprofen was the most abundant, with mean concentration of 114.9 ng/L and detection frequency of 91%, naproxen was also detectable at all sites from < MQL-43.2 ng/L, both presenting an excess of the S-(+)-enantiomer. Therefore to better understand the ecological risk posed from the trace organic contaminants on the aquatic organisms, chiral pollutants need analyzed at the enantiomeric levels. This is the first to profile the enantiospecific occurrence of NSAIDs in surface water in Beijing, China. It could provide useful information on environmental behaviors of chiral pollutants and facilitate more accurate environmental risk assessment.

Electrochemical degradation of naproxen from water by anodic oxidation with multiwall carbon nanotubes glassy carbon electrode

Naproxen (NPX) degradation was investigated by anodic oxidation both at constant potential and by cyclic voltammetry, using this last technique for optimizing reaction conditions and catalyst properties. Three multiwall carbon nanotubes (MWCNTs)-promoted electrodes were used (MWCNT, MWCNT-COOH and MWCNT-NH₂) and a two steps oxidation process was observed in all the cases. At the optimized conditions (volume of MWCNT = 15 μL), the influence of the scan rate indicates the diffusion-adsorption control of the process. Likewise, the kinetic study of NPX degradation at fix potential, considering two different stirring speeds (250 and 500 rpm), indicates that degradation rate increases with the stirring speed. After 20 h, NPX is degraded even an 82.5%, whereas the mineralization reaches almost 70%, as it was obtained from total organic carbon analysis. The pH effect was also analysed, in the range 5-11, observing a positive effect at low pH. Concerning the surface chemistry of the electrode, MWCNT-NH₂, with the highest isoelectric point (4.70), is the most promising material due to the improved interactions with the reactant. From these observations, a pathway is proposed, which includes two steps of electrochemical oxidation followed by subsequent oxidation steps, until mineralization of the NPX, attributed mainly to active chlorine species and ·OH.

New spectrophotometric/chemometric assisted methods for the simultaneous determination of imatinib, gemifloxacin, nalbuphine and naproxen in pharmaceutical formulations and human urine

In this paper, novel univariate and multivariate regression methods along with model-updating technique were developed and validated for the simultaneous determination of quaternary mixture of imatinib (IMB), gemifloxacin (GMI), nalbuphine (NLP) and naproxen (NAP). The univariate method is extended derivative ratio (EDR) which depends on measuring every drug in the quaternary mixture by using a ternary mixture of the other three drugs as divisor. Peak amplitudes were measured at 294nm, 250nm, 283nm and 239nm within linear concentration ranges of 4.0-17.0, 3.0-15.0, 4.0-80.0 and 1.0-6.0μgmL^-1 for IMB, GMI, NLP and NAB, respectively. Multivariate methods adopted are partial least squares (PLS) in original and derivative mode. These models were constructed for simultaneous determination of the studied drugs in the ranges of 4.0-8.0, 3.0-11.0, 10.0-18.0 and 1.0-3.0μgmL^-1 for IMB, GMI, NLP and NAB, respectively, by using eighteen mixtures as a calibration set and seven mixtures as a validation set. The root mean square error of predication (RMSEP) were 0.09 and 0.06 for IMB, 0.14 and 0.13 for GMI, 0.07 and 0.02 for NLP and 0.64 and 0.27 for NAP by PLS in original and derivative mode, respectively. Both models were successfully applied for analysis of IMB, GMI, NLP and NAP in their dosage forms. Updated PLS in derivative mode and EDR were applied for determination of the studied drugs in spiked human urine. The obtained results were statistically compared with those obtained by the reported methods giving a conclusion that there is no significant difference regarding accuracy and precision.

Pharmaceutical grey water footprint: Accounting, influence of wastewater treatment plants and implications of the reuse

Emerging pollutants, including pharmaceutical compounds, are producing water pollution problems around the world. Some pharmaceutical pollutants, which mainly reach ecosystems within wastewater discharges, are persistent in the water cycle and can also reach the food chain. This work addresses this issue, accounting the grey component of the water footprint (GWF_P) for four of the most common pharmaceutical compounds (carbamazepine (CBZ), diclofenac (DCF), ketoprofen (KTP) and naproxen (NPX)). In addition, the GWF_C for the main conventional pollutants is also accounted (nitrate, phosphates and organic matter). The case study is the Murcia Region of southeastern Spain, where wastewater treatment plants (WWTPs) purify 99.1% of the wastewater discharges and there is an important direct reuse of the treated wastewater in irrigation. Thus, the influence of WWTPs and reuse on the GWF is analysed. The results reveal that GWF_P, only taking into account pharmaceutical pollutants, has a value of 301 m³ inhabitant^-1 year^-1; considering only conventional pollutants (GWF_C), this value increases to 4718 m³ inhabitant^-1 year^-1. So, the difference between these values is such that in other areas with consumption habits similar to those of the Murcia Region, and without wastewater purification, conventional pollutants may well establish the value of the GWF. On average, the WWTPs reduce the GWF_C by 90% and the GWF_P by 26%. These different reductions of the pollutant concentrations in the treated effluents show that the GWF is not only due to conventional pollutants, and other contaminants can became critical, such as the pharmaceutical pollutants. The reuse further reduces the value of the GWF for the Murcia Region, by around 43.6%. However, the reuse of treated wastewater is controversial, considering the pharmaceutical contaminants and their possible consequences in the food chain. In these cases, the GWF of pharmaceutical pollutants can be used to provide a first approximation of the dilution that should be applied to the treated wastewater discharges when they are reused for another economic activity that imposes quality restrictions. For the case of agriculture in the Murcia Region, the dilution required is 2 (fresh water) to 1 (treated wastewater), taking into account the pollution thresholds established in this work.

Role of humic substances in the photodegradation of naproxen under simulated sunlight

Humic substances (HS) including humic acid (HA) and fulvic acid (FA) are ubiquitous in the natural waters. Although numerous studies documented their role in photodegradation of organic pollutants, the competitive effects of photosensitization and light-screening of HS on the photodegradation of pollutants are not yet clear. In this work, the role of HS in the photodegradation of the pharmaceutical naproxen (NP) was studied under simulated sunlight. The direct photodegradation quantum yield of NP in deionized water was 2.1 × 10^-2, and the apparent quantum yields for photosensitized degradation of NP in the presence of FA and HA were 2.3 × 10^-4 and 2.6 × 10^-5, respectively. Both direct and photosensitized photodegradation decreased with increasing pH, consistent with the trend of singlet oxygen (¹O₂) reaction rate constants of NP. HA inhibited the photodegradation of naproxen thoroughly. In contrast, FA accelerated the photodegradation of NP at lower substrate concentration and light intensity, and vice versa. Direct photodegradation of NP declined sharply with spectral radiation attenuation of UV region, when HS-mediated photosensitization predominantly accounted for the photodegradation. The direct photodegradation was ascribed to decomposition of excited triplet state of naproxen (³NP^∗) and self-sensitization effect involving ¹O₂. The FA-mediated photodegradation was mainly attributed to ¹O₂ oxidation in aerated solution. These findings are important for assessing the competitive effects of humic substances on the photodegradation of pollutants under various conditions in natural waters.

Chiral recognition of naproxen enantiomers based on fluorescence quenching of bovine serum albumin-stabilized gold nanoclusters

A simple, fast and green method for chiral recognition of S- and R-naproxen has been introduced. The method was based on quenching of the fluorescence intensity of bovine serum albumin-stabilized gold nanoclusters in the presence of naproxen enantiomers. The quenching intensity in the presence of S-naproxen was higher than R-naproxen when phosphate buffer solution at pH7.0 was used. The chiral recognition occurred due to steric effect between bovine serum albumin conformation and naproxen enantiomers. Two linear determination range were established as 7.4×10^-7-9.1×10^-6 and 9.1×10^-6-3.1×10^-5molL^-1 for both enantiomers and detection limits of 7.4×10^-8molL^-1 and 9.5×10^-8molL^-1 were obtained for S- and R-naproxen, respectively. The developed method showed good repeatability and reproducibility for the analysis of a synthetic sample. To make the procedure applicable to biological samples, the removal of heavy metals from the sample is suggested before any analytical attempt.

Development of a New Microextraction Fiber Combined to On-Line Sample Stacking Capillary Electrophoresis UV Detection for Acidic Drugs Determination in Real Water Samples

A new analytical method coupling a (off-line) solid-phase microextraction with an on-line capillary electrophoresis (CE) sample enrichment technique was developed for the analysis of ketoprofen, naproxen and clofibric acid from water samples, which are known as contaminants of emerging concern in aquatic environments. New solid-phase microextraction fibers based on physical coupling of chromatographic supports onto epoxy glue coated needle were studied for the off-line preconcentration of these micropollutants. Identification and quantification of such acidic drugs were done by capillary zone electrophoresis (CZE) using ultraviolet diode array detection (DAD). Further enhancement of concentration sensitivity detection was achieved by on-line CE “acetonitrile stacking” preconcentration technique. Among the eight chromatographic supports investigated, Porapak Q sorbent showed higher extraction and preconcentration capacities. The screening of parameters that influence the microextraction process was carried out using a two-level fractional factorial. Optimization of the most relevant parameters was then done through a surface response three-factor Box-Behnken design. The limits of detection and limits of quantification for the three drugs ranged between 0.96 and 1.27 µg∙L⁻¹ and 2.91 and 3.86 µg∙L⁻¹, respectively. Recovery yields of approximately 95 to 104% were measured. The developed method is simple, precise, accurate, and allows quantification of residues of these micropollutants in Genil River water samples using inexpensive fibers.

Occurrence of naproxen, ibuprofen, and diclofenac residues in wastewater and river water of KwaZulu-Natal Province in South Africa

The present paper reports a detailed study that is based on the monitoring of naproxen, ibuprofen, and diclofenac in Mbokodweni River and wastewater treatment plants (WWTPs) located around the city of Durban in KwaZulu-Natal Province of South Africa. Target compounds were extracted from water samples using a multi-template molecularly imprinted solid-phase extraction prior to separation and quantification on a high-performance liquid chromatography equipped with photo diode array detector. The analytical method yielded the detection limits of 0.15, 1.00, and 0.63 μg/L for naproxen, ibuprofen, and diclofenac, respectively. Solid-phase extraction method was evaluated for its performance using deionized water samples that were spiked with 5 and 50 μg/L of target compounds. Recoveries were greater than 80% for all target compounds with RSD values in the range of 4.1 to 10%. Target compounds were detected in most wastewater and river water samples with ibuprofen being the most frequently detected pharmaceutical. Maximum concentrations detected in river water for naproxen, ibuprofen, and diclofenac were 6.84, 19.2, and 9.69 μg/L, respectively. The concentrations of target compounds found in effluent and river water samples compared well with some studies. The analytical method employed in this work is fast, selective, sensitive, and affordable; therefore, it can be used routinely to evaluate the occurrence of acidic pharmaceuticals in South African water resources.

Investigating natural attenuation of pharmaceuticals through unsaturated column tests

The growing consumption of pharmaceuticals together with their incomplete removal in wastewater treatment plants (WWTPs) implies the occurrence of these compounds in natural water resources. To investigate the natural attenuation of selected pharmaceuticals (caffeine, acetaminophen, sulfamethoxazole, naproxen and carbamazepine) during vadose zone infiltration, unsaturated column (L 26.67 cm, Ø 7.62 cm) experiments, filled with a sandy-loamy soil, were performed using two input concentrations (100 and 1000 μg L^-1). The software Hydrus 1D was used to simulate experimental data. Caffeine and acetaminophen were never detected at the column outlet indicating a low environmental concern. On the other hand, attenuation of the detected pharmaceuticals could be reproduced by a combination of retardation and removal approaches. Carbamazepine is among the selected contaminants the most persistent. A dependence of removal rates on input concentrations was detected for sulfamethoxazole (μ_w from 2.78 d^-1 to 1.16 d^-1) and naproxen (μ_w from 1.16 d^-1 to 0.63 d^-1) attributed mainly to decreased metabolism of microorganisms when a higher input concentration is applied. Two transformation products (TPs) (N4-Acetylsulfamethoxazole and epoxycarbamazepine) derived from sulfamethoxazole and carbamazepine transformation, respectively, were detected during the experiment with the highest input concentration.

A novel sensor for determination of naproxen based on change in localized surface plasmon peak of functionalized gold nanoparticles

A highly selective and sensitive colorimetric sensor for the determination of naproxen (NAP) based on the aggregation of the thiolated β-cyclodextrin (Tβ-CD) functionalized gold nanoparticles (Tβ-CD-Au NPs) in the presence of NAP and Zn²⁺is described. The hydrophobic end of NAP interacts with the immobilized Tβ-CD on the Au NPs and forms the complex of Tβ-CD:NAP while the Zn²⁺ ions form a 1:2 complex of (NAP)₂Zn with the carboxyl groups of NAP resulting in the aggregation of functionalized gold nanoparticles. As a result of aggregation, the localized surface plasmon resonance (LSPR) band of functionalized gold nanoparticles around 520nm decreases and a new red shifted band at 650nm appears which increases gradually as the function of NAP concentration. The calibration graph derived from the intensity ratios of absorbance at 650nm to 520nm was linear in the concentration range of 4-180μgL^-1of NAP. At the optimum conditions, the limit of detection (LOD) and quantification (LOQ) were found to be 0.6 and 2.1μgL^-1, respectively and the relative standard deviation at 20μgL^-1of NAP (n=5) was 2.5%. The selectivity and applicability of the method was verified through analyzes of the synthetic samples containing the major interference compounds reported in literature as well as tablets, wastewater and urine samples. The accuracy of the method was evaluated by recovery experiments and analysis of pharmaceutical tablets.

Non-steroidal anti-inflammatory drugs in the watercourses of Elbe basin in Czech Republic

Non-steroidal anti-inflammatory drugs (NSAIDs) belong to most used pharmaceuticals in the human and veterinary medicine. The widespread consumption of NSAIDs has led to their ubiquitous occurrence in water environment including large river systems. In the present study, concentrations of the five most frequently used NSAIDs (ibuprofen, diclofenac, naproxen, ketoprofen and indomethacin) were determined in the watercourses of the river Elbe basin in Czech Republic. The presence of the pharmaceuticals was measured at 29 sampling sites including urban and rural areas, small creeks and main tributaries of the Elbe monthly from April to December of 2011. For the NSAIDs quantitation, the comprehensive analytical method combing pentafluorobenzyl bromide (PFBBr) derivatization with highly sensitive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) was developed. Although the content of all NSAIDs varied at the particular sampling points significantly, total amount of particular compounds was relatively stable during all monitored periods with only non-significant increase in the spring and autumnal months. Ibuprofen was found to be the most abundant drug with maximum concentration of 3210 ng/L, followed by naproxen, diclofenac and ketoprofen (1423.8 ng/L, 1080 ng/L and 929.8 ng/L, respectively). Indomethacin was found only at several sampling sites (maximum concentration of 69.3 ng/L). Concentrations of all compounds except ibuprofen were significantly higher at sampling sites with low flow rates (creeks), followed by the biggest watercourses.

Detection and quantification of acidic drug residues in South African surface water using gas chromatography-mass spectrometry

A method was optimized for derivatization, separation, detection and quantification of salicylic acid, acetylsalicylic acid, nalidixic acid, ibuprofen, phenacetin, naproxen, ketoprofen, meclofenamic acid and diclofenac in surface water using gas chromatography-mass spectrometry. For most of the acidic drugs, recovery was in the range 60-110% and the percent standard deviation was below 15% for the entire method, with limits of detection ranging from 0.041 to 1.614 μg L^-1. The developed method was applied in the analysis of acidic drugs in Umgeni River system, KwaZulu-Natal South Africa. All of the selected acidic drugs were detected and quantified, their concentration in Umgeni River system ranged from 0.0200 to 68.14 μg L^-1.

Development of potential candidate reference materials for drugs in bottom sediment, cod and herring tissues

Regular use of a reference material and participation in a proficiency testing program can improve the reliability of analytical data. This paper presents the preparation of candidate reference materials for the drugs metoprolol, propranolol, carbamazepine, naproxen, and acenocoumarol in freshwater bottom sediment and cod and herring tissues. These reference materials are not available commercially. Drugs (between 7 ng/g and 32 ng/g) were added to the samples, and the spiked samples were freeze-dried, pulverized, sieved, homogenized, bottled, and sterilized by γ-irradiation to prepare the candidate materials. Procedures for extraction and liquid chromatography coupled with tandem mass spectrometry were developed to determine the drugs of interest in the studied material. Each target drug was quantified using two analytical procedures, and the results obtained from these two procedures were in good agreement with each other. Stability and homogeneity assessments were performed, and the relative uncertainties due to instability (for an expiration date of 12 months) and inhomogeneity were 10-25% and 4.0-6.8%, respectively. These procedures will be useful in the future production of reference materials.

Sorption, photodegradation, and chemical transformation of naproxen and ibuprofen in soils and water

Pharmaceutically active compounds (PhACs) are released into the environment where they undergo soil sorption, photodegradation, and chemical transformation into structurally similar compounds. Here we report on studies of naproxen (NAP) and ibuprofen (IBP), two widely-used nonsteroidal anti-inflammatory drugs (NSAIDS), in soils and water. Organic matter (OM) was observed to play an important role in each of these processes. Sorption was observed to be stronger and nonlinear in higher OM soils while weaker but still significant in lower OM, higher clay soils; the amphiphilic nature of these two PhACs combined with the complex charged and nonpolar surfaces available in the soil was observed to control the sorption behavior. Simulated solar photodegradation rates of NAP and IBP in water were observed to change in the presence of humic acid or fulvic acid. Structural analogs of each compound were observed as the result of chemical transformation in both photoexposed aqueous solutions and non-photoexposed soil. Two of these transformation products were detected as both soil and photo transformation products for both PhACs. OM was observed to influence the chemical transformation of both pharmaceuticals.

Suitability of passive sampling for the monitoring of pharmaceuticals in Finnish surface waters

The occurrence of five pharmaceuticals, consisting of four anti-inflammatory and one antiepileptic drug, was studied by passive sampling and grab sampling in northern Lake Päijänne and River Vantaa. The passive sampling was performed by using Chemcatcher® sampler with a SDB-RPS Empore disk as a receiving phase. In Lake Päijänne, the sampling was conducted during summer 2013 at four locations near the discharge point of a wastewater treatment plant and in the years 2013 and 2015 at four locations along River Vantaa. The samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in the multiple reaction monitoring mode. The concentrations of carbamazepine, diclofenac, ibuprofen, ketoprofen, and naproxen in Lake Päijänne determined by passive sampling ranged between 1.4-2.9 ng L(-1), 15-35 ng L(-1), 13-31 ng L(-1), 16-27 ng L(-1), and 3.3-32 ng L(-1), respectively. Similarly, the results in River Vantaa ranged between 1.2-40 ng L(-1), 15-65 ng L(-1), 13-33 ng L(-1), 16-31 ng L(-1), and 3.3-6.4 ng L(-1). The results suggest that the Chemcatcher passive samplers are suitable for detecting pharmaceuticals in lake and river waters.

The role of sorption and biodegradation in the removal of acetaminophen, carbamazepine, caffeine, naproxen and sulfamethoxazole during soil contact: A kinetics study

In countries like Spain, where water is a limited resource, reusing effluents from wastewater treatment plants may imply the introduction of incompletely eliminated pollutants into the environment. Therefore, this work identified the role of sorption and biodegradation in attenuating pharmaceutical compounds (acetaminophen, carbamazepine, caffeine, naproxen and sulfamethoxazole) in natural soil. It also determined which sorption and removal ("sorption+biodegradation") kinetics models describe the behaviour of these substances in the water-soil system. Presence of potential transformation products (TPs) as a result of pharmaceuticals biodegradation was also studied. To this end, serial batch-type experiments were performed with a soil:water ratio of 1:4 and an initial pharmaceutical concentration of 100μgL(-1). Despite results are dependent on soil characteristics, they revealed that, for those substances with a higher affinity to the soil used (loamy sand), sorption seems to play a key role during the first 48h of contact with soil, and gives way to biodegradation afterwards. The sorption of the pharmaceuticals studied follows a pseudo second-order kinetics. Caffeine and sulfamethoxazole displayed the fastest initial sorption velocities (h=2055 and h=228μgkg(-1)h(-1), respectively). The removal kinetics experiments, satisfactorily simulated by the first-order kinetics model, indicated the presence of potential microbial adaptation to degradation. Indeed, half-lives decreased from 1.6- to 11.7-fold with respect to initial values. The microbial capacity to degrade sulfamethoxazole could be a matter of concern if bacteria have developed resistance to this antibiotic. Caffeine, acetaminophen and sulfamethoxazole were mitigated to a greater extent, whereas the removal of naproxen and carbamazepine was more limited. The appearance of epoxy-carbamazepine and N4-acetyl-sulfamethoxazole as possible TPs of carbamazepine and sulfamethoxazole, respectively, indicated that biodegradation was incomplete and showed the capacity of soil microbes to transform these substances.

Removal rates of antibiotics in four sewage treatment plants in South India

The occurrence and removal of seven selected pharmaceutical compounds (PCs) in sewage treatment plants (STPs) in South India were investigated. The PCs selected for this study were sulfamethoxazole (SMX), trimethoprim (TMP), chloramphenicol (CAP), erythromycin (ERY), naproxen (NPX), bezafibrate (BZF), and ampicillin (AMP). Wastewater samples were collected from inlet and outlet of the STPs during pre-monsoon, monsoon, and post-monsoon seasons to investigate the seasonal influences in occurrence and removal rates. The analytical method was based on simultaneous extraction of all target compounds by solid phase extraction (SPE), using a hydrophilic-lipophilic-balanced (HLB) sorbent followed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The STP that catered exclusively to domestic wastewater had lesser concentrations of PCs compared to the STPs serving the combined hospital and domestic effluents. SMX was the dominant compound in all effluents with the highest concentration at 3.2 μg/L in the outlet of an STP. TMP and ERY were the other PCs present at higher concentrations in STP outlets (1 μg/L and 0-0.13 μg/L, respectively). Removal rates varied from 100 % for BZF to 60-100 % for SMX, CTX, and AMP.

Sorption of diclofenac and naproxen onto MWCNT in model wastewater treated by H2O2 and/or UV

The application of oxidation processes such as UV and/or H2O2 will change the physicochemical properties of carbon nanotubes (CNT). It may affect the sorption affinity of CNT to different contaminants and then affect their fate in the environment. In the present study the adsorption of two very common used pharmaceuticals (diclofenac and naproxen) onto CNT treated by UV, H2O2 or UV/H2O2 was investigated. Four different adsorption models (Freundlich, Langmuir, Temkin, Dubinin-Radushkevich) were tested. The best fitting of experimental data was observed for Freundlich or Langmuir model. The significant relationships between Q calculated from Langmuir model with O% and dispersity were observed. Kinetics of diclofenac and naproxen followed mainly pseudo-second order indicating for chemisorption limiting step of adsorption. The data showed that the mechanism of sorption was physical or chemical depending on the type of CNT modification.

Environmental fate of naproxen, carbamazepine and triclosan in wastewater, surface water and wastewater irrigated soil - Results of laboratory scale experiments

Lab-scale photolysis, biodegradation and transport experiments were carried out for naproxen, carbamazepine and triclosan in soil, wastewater and surface water from a region where untreated wastewater is used for agricultural irrigation. Results showed that both photolysis and biodegradation occurred for the three emerging pollutants in the tested matrices as follows: triclosan>naproxen>carbamazepine. The highest photolysis rate for the three pollutants was obtained in experiments using surface water, while biodegradation rates were higher in wastewater and soil than in surface water. Carbamazepine showed to be recalcitrant to biodegradation both in soil and water; although photolysis occurred at a higher level than biodegradation, this compound was poorly degraded by natural processes. Transport experiments showed that naproxen was the most mobile compound through the first 30cm of the soil profile; conversely, the mobility of carbamazepine and triclosan through the soil was delayed. Biodegradation of target pollutants occurred within soil columns during transport experiments. Triclosan was not detected either in leachates or the soil in columns, suggesting its complete biodegradation. Data of these experiments can be used to develop more reliable fate-on-the-field and environmental risk assessment studies.

SIMPLE, SENSITIVE AND SELECTIVE SPECTROPHOTOMETRIC ASSAY OF NAPROXEN IN PURE, PHARMACEUTICAL PREPARATION AND HUMAN SERUM SAMPLES

Two simple, rapid and sensitive spectrophotometric methods have been developed for the determination of naproxen in pure, pharmaceutical preparation and human serum samples. These methods are based on the formation of yellow ion-pair complexes between naproxen and two sulfophthalein acid dyes, namely bromocresol green (BCG method) and bromothymol blue (BTB method). The resulting complexes were measured at 424 nm (BCG method) and at 422 nm (BTB method). The effects of variables such as reagent concentration and reaction time were investigated to optimize the procedure. Beer's law was obeyed in the concentration range of 10-105 µg/mL and 5-85 µg/mL and the detection limits were found to be 0.347 and 0.31 µg/mL for BCG and BTB methods, respectively. The developed methods have been successfully applied for the determination of naproxen in bulk drugs, pharmaceutical formulations and human serum samples with good accuracy and precision. The results are comparable to those of reference methods, and hence are recommended for quality control and routine analysis.

A comparative study of the novel spectrophotometric methods versus conventional ones for the simultaneous determination of Esomeprazole magnesium trihydrate and Naproxen in their binary mixture

Two novel simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra are developed and validated for simultaneous determination of Esomeprazole magnesium trihydrate (ESO) and Naproxen (NAP) namely; absorbance subtraction and ratio difference. The results were compared to that of the conventional spectrophotometric methods namely; dual wavelength and isoabsorptive point coupled with first derivative of ratio spectra and derivative ratio. The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for determination of ESO and NAP in their laboratory prepared mixtures and pharmaceutical preparation. No preliminary separation steps are required for the proposed spectrophotometeric procedures. The statistical comparison showed that there is no significant difference between the proposed methods and the reported method with respect to both accuracy and precision.

Removal of acetaminophen and naproxen by combined coagulation and adsorption using biochar: influence of combined sewer overflow components

The combined coagulation and adsorption of targeted acetaminophen and naproxen using activated biochar and aluminum sulfate were studied under various synthetic "combined sewer overflow" (CSO) conditions. The biochar demonstrated better adsorption performance for both acetaminophen and naproxen (removal, 94.1 and 97.7%, respectively) than that of commercially available powdered activated carbon (removal, 81.6 and 94.1%, respectively) due to superior carbonaceous structure and surface properties examined by nuclear magnetic resonance analysis. The adsorption of naproxen was more favorable, occupying active adsorption sites on the adsorbents by naproxen due to its higher adsorption affinity compared to acetaminophen. Three classified CSO components (i.e., representing hydrophobic organics, hydrophilic organics, and inorganics) played different roles in the adsorption of both adsorbates, resulted in inhibition by humic acid complexation or metal ligands and negative electrostatic repulsion under adsorption and coagulation combined system. Adsorption alone with biochar was determined to be the most effective adsorptive condition for the removal of both acetaminophen and naproxen under various CSO conditions, while both coagulation alone and combined adsorption and coagulation failed to remove the acetaminophen and naproxen adequately due to an increase in ionic strength in the presence of spiked aluminum species derived from the coagulant.

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with (14)C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules.

Occurrence of selected pharmaceuticals in the principal sewage treatment plants in Rome (Italy) and in the receiving surface waters

This paper provides data on the occurrence of selected human pharmaceuticals (carbamazepine, clofibric acid, diclofenac, fenofibrate, fenoprofen, gemfibrozil, ibuprofen, ketoprofen, and naproxen) including steroid hormones (17β-estradiol, 17α-ethinylestradiol, and estrone) in influents/effluents to/from the four principal wastewater treatment plants (WWTPs) serving the city of Rome (Italy), in two different sampling campaigns. Target compounds were also analyzed in the receiving River Tiber and River Aniene. Analytical determination was carried out by LC-MS/MS after sample cleanup and concentration by off-line solid-phase extraction (SPE). The aim of the study was to increase the information currently available on the presence and persistence of pharmaceuticals in Italian urban wastewaters and to evaluate the environmental impact of the pharmaceutical residues discharged through effluents into the receiving rivers. Results indicated that after the treatment processes, most of pharmaceuticals were not completely eliminated, as average removal efficiencies were in the 14-100% wide range during both sampling periods, with higher yields in spring than in winter. Levels detected in overall samples ranged from 5 to 2,230 ng/L in influents and from 5 to 1,424 ng/L in effluents. Carbamazepine, diclofenac, ibuprofen, and gemfibrozil showed the highest persistence to removal. Concentrations in the receiving waters were about one order of magnitude lower than in effluents, with a tendency to increase progressively through the urban tract of the river. Finally, an environmental risk analysis showed that carbamazepine, gemfibrozil, and estrone can pose a high risk at the concentrations detected in effluents and a medium risk in rivers, highlighting their potential hazard for the health of the aquatic ecosystem.

Removal of pain-relieving drugs from aqueous solutions using Octolig and selected metalloligs

The possibility of removing certain pharmaceuticals (acetaminophen and naproxen) from water was tested using Octolig, a commercially available material with polyethylenediimine moieties covalently attached to high-surface area silica gel. In addition, the efficacy of two transition metals (cupric and ferric) derivatives of Octolig was tested. Previously amoxicillin had been successfully subjected to column chromatography for removal by means of ion encapsulation, the effectiveness of which would depend upon having appropriate anionic functional groups. Both pharmaceuticals were removed by passage over Octolig columns, though with less effectiveness than was achieved previously with xanthenylbenzenes or selected food dyes. Somewhat greater removal, ca 90%, was achieved using Cuprilig, the copper(II) derivative, but not with Ferrilig the iron(III) derivative, perhaps because the hydroxide counter ion was more closely associated with the transition metal ion and was not available to assist in proton removal.

Occurrence and behavior of the chiral anti-inflammatory drug naproxen in an aquatic environment

The present study reports on the occurrence and chiral behavior of the anti-inflammatory drug (S)-naproxen (NAP)-(S)-2-(6-methoxynaphthalen-2-yl)propionic acid-in an aquatic environment under both field and laboratory conditions. In influents and effluents of sewage treatment plants (STPs) in the Tama River basin (Tokyo), (S)-NAP was detected at concentrations of 0.03 µg L(-1) to 0.43 µg L(-1) and 0.01 µg L(-1) to 0.11 µg L(-1), respectively. The concentrations of a major metabolite, 6-O-desmethyl NAP (DM-NAP) were up to 0.47 µg L(-1) and 0.56 µg L(-1) in influents and effluents, respectively. (R)-naproxen was not detected in STP influents, although it was present in effluents, and the enantiomeric faction (= S/[S + R]) of NAP ranged from 0.88 to 0.91. Under laboratory conditions with activated sludge from STPs, rapid degradation of (S)-NAP to DM-NAP and chiral inversion of (S)-NAP to (R)-NAP were observed. During river die-away experiments, degradation and chiral inversion of NAP were extremely slow. In addition, chiral inversion of (S)-NAP to (R)-NAP was not observed during photodegradation experiments. In the river receiving STP discharge, NAP and DM-NAP concentrations reached 0.08 µg L(-1) and 0.16 µg L(-1) , respectively. The enantiomeric faction of NAP in the river ranged from 0.84 to 0.98 and remained almost unchanged with the increasing contribution of rainfall to the river water. These results suggest that the absence and decrease of (R)-NAP in river waters could indicate the inflow of untreated sewage. E

Evaluation of in-line Raman spectroscopic monitoring of size reduction during wet media milling of Biopharmaceutics Classification System Class II drugs

The aim of this study was to evaluate in-line Raman spectroscopy for monitoring the progress of particle size reduction in real time during wet-stirred media milling of two Biopharmaceutics Classification System (BCS) Class II drugs, griseofulvin and naproxen. To develop a validated online Raman method, Raman analyses were carried out offline by taking samples from the mill at various milling times. A multivariate linear model (partial least squares, PLS) was fitted to the raw data obtained from the Raman measurements and good linearity between online and offline Raman spectra was found. Line intensities (I) of the in-line spectra obtained during the wet media milling were processed by multivariate analyses and correlated with both the median size (d50) and the 90% passing particle size (d90), which were measured offline by laser diffraction. A two-parameter exponential growth model of the form d = exp[A(I - I0)] was found to establish a good correlation (R(2) > 0.90) as a statistically significant model with statistically significant parameters (P < 10(-4)). The correlations were applicable to milled suspensions with particles in the approximate size range of 0.1-6 μm for griseofulvin and 0.1-8 μm for naproxen. These results suggest that in-line Raman spectroscopy can be used to successfully monitor the progress of particle size reduction during wet media milling.

Transformation and removal pathways of four common PPCP/EDCs in soil

Pharmaceutical and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) enter the soil environment via irrigation with treated wastewater, groundwater recharge, and land application of biosolids. The transformation and fate of PPCP/EDCs in soil affects their potential for plant uptake and groundwater pollution. This study examined four PPCP/EDCs (bisphenol A, diclofenac, naproxen, and 4-nonylphenol) in soil by using (14)C-labeling and analyzing mineralization, extractable residue, bound residue, and formation of transformation products. At the end of 112 d of incubation, the majority of (14)C-naproxen and (14)C-diclofenac was mineralized to (14)CO2, while a majority of (14)C-bisphenol A and (14)Cnonylphenol was converted to bound residue. After 112 d, the estimated half-lives of the parent compounds were only 1.4-5.4 d. However a variety of transformation products were found and several for bisphenol A and diclofenac were identified, suggesting the need to consider degradation intermediates in soils impacted by PPCP/EDCs.

Effective anodic oxidation of naproxen by platinum nanoparticles coated FTO glass

This study investigated applications of the electrochemical anodic oxidation process with Pt-FTO and Pt/MWCNTs-FTO glasses as anodes on the treatment of one of the most important emerging contaminants, naproxen. The anodes used in this study have been synthesized using commercial FTO, MWCNTs and Pt nanoparticles (PtNP). XRD patterns of Pt nanoparticles coated on FTO and MWCNTs revealed that MWCNTs can prevent the surface of PtNPs from sintering and thus provide a greater reaction sites density to interact with naproxen, which have also been confirmed by higher degradation and mineralization efficiencies in the Pt/MWCNTs-FTO system. Results from the CV analysis showed that the Pt-FTO and Pt/MWCNTs-FTO electrodes possessed dual functions of decreasing activation energy and interactions between hydroxyl radicals to effectively degrade naproxen. The lower the solution pH value, the better the degradation efficiency. The existence of humic acid indeed inhibited the degradation ability of naproxen due to the competitions in the multiple-component system. The electrochemical degradation processes were controlled by diffusion mechanism and two major intermediates of 2-acetyl-6-methoxynaphthalene and 2-(6-Hydroxy-2-naphthyl)propanoic acid were identified. This study has successfully demonstrated new, easy, flexible and effective anodic materials which can be feasibly applied to the electrochemical oxidation of naproxen.

Environmental risk assessment of selected pharmaceuticals in Turkey

In this study, environmental risks of selected pharmaceuticals were investigated to assess potential hazards. Ciprofloxacin, Clarithromycin, Cefuroxime axetil, antibiotics, Benzalkoniuman antiseptic, Paracetamol, an analgesic, and Naproxen, an anti-inflammatory, were selected due to their high rate of usage in Turkey. Ciprofloxacin was found to have the highest risk due to its high PEC/PNEC ratio (28.636). Benzalkonium, Paracetamol and Clarithromycin have a potential to cause environmental hazards. The biodegradation and biological concentration factors (BCF) of the drugs were also determined using EPA/STWIN and EPA/BCFWIN programs. The results illustrated that these pharmaceuticals are nonbiodegradable in wastewater treatment plants. The BCFs of Benzalkonium and Clarithromycin were found to be very high, 70.790 L/kg and 56.490 L/kg, respectively. It was suggested that alternative treatment methods other than biological ones should be investigated for these pharmaceuticals because of their low biodegradability. Also, unnecessary use of antibiotics is supposed to be discouraged to reduce environmental hazards.

Non-steroidal anti-inflammatory drugs in Indian rivers

Pharmaceutical concentration data for Indian surface waters are currently scarce. Sewage often enters Indian rivers without prior treatment, and so previously reported environmental concentrations from regions with routinely implemented sewage treatment cannot simply be used to predict concentrations in Indian surface water. Improved knowledge of pharmaceutical concentrations in Indian waters would enable determination of potential risks posed to aquatic wildlife and human health in this region. The concentrations of five common non-steroidal anti-inflammatory drugs (NSAIDs; diclofenac, ketoprofen, naproxen, ibuprofen, and acetylsalicylic acid) were determined in surface waters from 27 locations of the Kaveri, Vellar, and Tamiraparani Rivers in southern India. The samples were extracted by solid-phase extraction and analyzed by GC-MS. The measured concentrations of four of the five drugs in this reconnaissance were relatively similar to those reported elsewhere (ND-200 ng/l); however, acetylsalicylic acid, the most readily degradable of the investigated drugs, was found at all sites and at considerably higher concentrations (up to 660 ng/l) than reported in European surface waters. This is the first report on the occurrence of NSAIDs in Indian rivers. The finding of elevated concentrations of acetylsalicylic acid is most likely a result of direct discharges of untreated sewage. Therefore, readily degradable pharmaceuticals may present larger concern in regions without consistent sewage treatment. Based on measured environmental concentrations, the risks of direct toxicity to aquatic wildlife and of humans consuming the water are discussed.