HPLC determination of ibuprofen, diclofenac and salicylic acid using hollow fiber-based liquid phase microextraction (HF-LPME)

Ionic liquid-based dispersive liquid-liquid microextraction of anthelmintic drug residues in small-stock meat followed by LC-ESI-MS/MS detection

An ionic liquid-based dispersive liquid-liquid microextraction (IL-DLLME) of 20 anthelmintic drugs followed and detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed, optimized, and validated. The parameters affecting the anthelmintic extraction efficiencies such as selection of extraction solvent (ionic liquids), selection of disperser solvent, volume of extraction solvent, volume of disperser solvent, pH of the aqueous phase, extraction time, salt addition, and centrifugation time were optimized. Validation was conducted according to ISO/IEC 17025:2017 and Commission Implementing Regulation (EU) 2021/808 of 22 March 2021. Validation parameters such as calibration function, matrix effect, limit of detection (LOD), limit of quantification (LOQ), decision limit (CCα), accuracy, and precision were established. Coefficient of determination (R 2) values ranging from .99938 to .99995 were obtained using the matrix calibration curve spiked at 0, 0.25, 1.0, 1.5, and 2.0 times MRL. The LODs and LOQs were calculated using the standard deviation of the response and the slopes of the calibration curves ranged from 0.35 to 26.1 μg/kg and from 1.2 to 87.0 μg/kg, respectively, and were dependent on calibration range. The CCα values ranged from 23 to 1022.0 μg/kg and are also dependent on the MRL concentration levels. The coefficient of variation (CV) values calculated are within the reproducibility range of 16%-30% adapted from the Horwitz Equation CV = 2(1-0.5 log C) and ranged from 1.7% to 16.9%. The developed and validated and the standard QuEChERS method were compared. The IL-DLLME LC-MS/MS method was applied to 32 small stock (18 caprine [goat] and 14 ovine [sheep]) liver samples received from municipal abattoirs at Botswana National Veterinary Laboratory for the analysis of anthelmintic drug residues. The results obtained indicated that the anthelmintic drug residues were all below the detection capability, and therefore, the samples were passed as fit for human consumption.

Hollow Fibre-Supported Liquid Membrane for the Determination of Sulfonamide Residues in Egg Samples

In this study, a three-phase hollow fibre-supported liquid membrane (HF-SLM) technique incorporated with high-performance liquid chromatography (HPLC) coupled with diode array detection (DAD) was developed for the extraction, clean-up, and determination of fifteen sulfonamide residues in chicken egg samples. The residues were extracted from the 5 mL sample solution of pH 2.5 into a thin layer of organic phase (1-octanol with 10% TOPO) immobilised in hollow fibre pores and then back-extracted into approximately 6 μL of aqueous phase (pH 13) located in the lumen of the hollow fibre. After extraction, 6 μL of the acceptor phase was injected into an HPLC instrument for subsequent analysis. Under optimum conditions, the limit of detection (LOD) and limit of quantification (LOQ) values ranged from 0.8–7.9 μg·kg−1 and from 2.4–21.0 μg·kg−1, respectively, linearity in the range of 5 1 000 μg·kg−1, and intra- and inter-day precision (%RSD) values at three concentration levels (50, 100, and 500 μg·L−1) ranged from 6.2–15.7%, 7.3–15.0%, and 7.3–14.6%; and 6.4–17.4%, 4.3–16.2%, and 8.3–16.5%, respectively, were obtained. The accuracy of the method, expressed as percentage recovery, was in the range of 71.0–98.7%, with corresponding %RSD (n = 6) values ranging from 1.9–9.9% being obtained. The developed method provided enrichment factors in the range of 17.1 to 541.4. The applicability of the proposed method was also evaluated by analysing egg samples, which were randomly collected from local supermarkets located in Gauteng Province, South Africa. The results obtained revealed that the developed method has the potential to be used as an alternative method for the determination of sulfonamide residues in egg and related complex samples.

A Visible-Light-Active CuS/MoS2/Bi2WO6 Aptamer Sensitively Detects the Non-Steroidal Anti-Inflammatory Drug Diclofenac

Diclofenac is a non-steroidal, anti-inflammatory drug and is clinically used for the treatment of osteoarthritis, non-articular rheumatism, etc. This research aimed to demonstrate the creation of an upgraded photoelectrochemical (PEC) aptamer sensor for detecting diclofenac (DCF) with high sensitivity. In this work, photoactive materials and bio-identification components served as visible-light-active CuS/MoS₂/Bi₂WO₆ heterostructures and aptamers, respectively. CuS and MoS₂/Bi₂WO₆ were combined to improve photocurrent responsiveness, which helped the structure of PEC aptasensors. Additionally, the one-pot synthesis of CuS/MoS₂/Bi₂WO₆ was ecologically beneficial. With these optimizations, the photocurrent response of aptamer/CS/CuS/MoS₂/Bi₂WO₆ exhibited linearity between 0.1 and 500 nM DCF. The detection limit was 0.03 nM (S/N = 3). These results suggest that the PEC sensing technique might produce an ultra-sensitive sensor with high selectivity and stability for DCF detection.

Development and Validation of an HPLC-UV Method for the Quantification of 4'-Hydroxydiclofenac Using Salicylic Acid: Future Applications for Measurement of In Vitro Drug-Drug Interaction in Rat Liver Microsomes

Salicylic acid is a key compound in nonsteroidal anti-inflammatory drugs that has been recently used for preventing the risk of hospitalization and death among COVID-19 patients and in preventing colorectal cancer (CRC) by suppressing two key proteins. Understanding drug−drug interaction pathways prevent the occurrence of adverse drug reactions in clinical trials. Drug−drug interactions can result in the variation of the pharmacodynamics and pharmacokinetic of the drug. Inhibition of the Cytochrome P450 enzyme activity leads to the withdrawal of the drug from the market. The aim of this paper was to develop and validate an HPLC-UV method for the quantification of 4′-hydroxydiclofenac as a CYP2C9 metabolite using salicylic acid as an inhibitor in rat liver microsomes. A CYP2C9 assay was developed and validated on the reversed phase C18 column (SUPELCO 25 cm × 4.6 mm × 5 µm) using a low-pressure gradient elution programming at T = 30 °C, a wavelength of 282 nm, and a flow rate of 1 mL/min. 4′-hydroxydiclofenac demonstrated a good linearity (R2 > 0.99), good reproducibility, low detection, and quantitation limit, and the inter and intra-day precision met the ICH guidelines (<15%). 4′-hydroxydiclofenac was stable for three days and showed an acceptable accuracy and recovery (80−120%) within the ICH guidelines in a rat liver microsome sample. This method will be beneficial for future applications of the in vitro inhibitory effect of salicylic acid on the CYP2C9 enzyme activity in rat microsomes and the in vivo administration of salicylic acid in clinical trials.

At-line coupling of hollow fiber liquid-phase microextraction to capillary electrophoresis for trace determination of acidic drugs in complex samples

Direct analysis of complex samples is demonstrated by the at-line coupling of hollow fiber liquid-phase microextraction (HF-LPME) to capillary electrophoresis (CE). The hyphenation of the preparative and the analytical technique is achieved through a 3D-printed microextraction device with an HF located in a sample vial of a commercial CE instrument. The internal geometry of the device guides the CE separation capillary into the HF and the CE injection of the HF-LPME extract is performed directly from the HF lumen. The 3D-printing process ensures uniform dimensions of the devices, their constant position inside the sample vial, and excellent repeatability of the HF-LPME as well as the CE injection. The devices are cheap (∼0.01 €) and disposable, thus eliminating any possible sample-carryover, moreover, the at-line CE analysis of the extract is performed fully autonomously with no need for operator's intervention. The developed HF-LPME/CE-UV method is applied to the determination of acidic drugs in dried blood spot and wastewater samples and is characterized by excellent repeatability (RSD, 0.6-9.6%), linearity (r², 0.9991-0.9999), enrichment (EF, 29-97), sensitivity (LOD, 0.2-3.4 μg/L), and sample throughput (7 samples/h). A further improvement of selected characteristics of the analytical method is achieved by the at-line coupling of HF-LPME to capillary isotachophoresis (ITP) with electrospray ionization-mass spectrometry (ESI-MS). The HF-LPME/ITP-ESI-MS system facilitates enhanced selectivity, matrix-free analytical signals, and up to 34-fold better sensitivity due to the use of ESI-MS detection and additional on-capillary ITP preconcentration of the HF-LPME extracts.

Two different synchronous spectrofluorimetric approaches for simultaneous determination of febuxostat and ibuprofen

Two green, simple and sensitive synchronous spectrofluorimetric methods were developed for the first time for the simultaneous estimation of febuxostat (FEB) and ibuprofen (IBU). Method I is constant-wavelength synchronous spectrofluorimetry where FEB and IBU were recorded at 329 and 258 nm, respectively, using Δλ of 40 nm. Method II is constant-energy synchronous spectrofluorimetry using a wavenumber interval of -4000 cm-1. All measurements were carried out in a borate buffer of pH 7 and distilled water for dilution which increased the methods' greenness. The two methods were rectilinear over concentration ranges of 30.0-700.0 ng ml-1 and 0.5-9.0 µg ml-1 in the first method and 20.0-500.0 ng ml-1 and 0.1-8.0 µg ml-1 in the second method for FEB and IBU, respectively. High sensitivity was attained for the two drugs with limits of quantitations (LODs) down to 0.41 and 5.51 ng ml-1 in the first method and 0.25 and 3.32 ng ml-1 in the second method for FEB and IBU, respectively. Recovery percentages were in the range of 97.3-101.9% after extraction from spiked human plasma samples, demonstrating high bioanalytical applicability. The two methods were further applied to tablet dosage forms with good recovery results. The methods' greenness was assessed according to the analytical Eco-Scale and Green Analytical Procedure Index guidelines.

The study of chiral recognition on ibuprofen enantiomers by a fluorescent probe based on β-cyclodextrin modified ZnS:Mn quantum dots

In this paper, a fluorescence method for chiral detection of ibuprofen and its enantiomer was developed. The L-cystenine-capped ZnS:Mn quantum dots were synthesized and functionalized with β-cyclodextrin (β-CD-QDs). The β-CD-QDs exhibited different quenching effect to the S-(+)-ibuprofen and the R-(-)-ibuprofen based on the advantage of the inclusion complex of cyclodextrin. It was found that the quenching of β-CD-QDs by S-(+)-ibuprofen was due to the formation of inclusion complex through both static quenching and photoinduced electron transfer, but only slight quenching with the R-(-)-ibuprofen. The stability constants derived from Hildebrand-Benesi method and absorption titration experiments were applied to determine the stability constants of the formed complexes, the double reciprocal plots suggest that a conclusion complex with a ratio of 1:1 was formed between β-CD-QDs and S-(+)-ibuprofen, but did not with the R-(-)-ibuprofen. The fluorescence intensity of the β-CD-QDs was linearly dependent on the concentration of the S-(+)-IBP in the range of 0-0.5 nmol/L with an limit of detection of 0.29 nmol/L.

Non-steroidal anti-inflammatory drugs in the environment: Where were we and how far we have come?

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most well-known pharmaceuticals with a broad scope of properties that are widely used in human and veterinary medicine. Because of their extensive utilization, NSAIDs are commonly identified in the environment as trace emerging contaminants. Regardless of vast experience with these drugs, NSAIDs are full of contradictions that trigger major concerns for environmental researchers. A limited understanding on NSAID's occurrence, distribution and eco-toxicological effects have led to an escalated dilemma in the last decade. Thus, a broad-spectrum study covering all aspects of occurrence, detection and removal is required to meet the fundamental levels of knowledge on the effects of NSAIDs in all exposed environmental aspects. Therefore, this paper focuses on classifying the sources and entry points of residual NSAIDs. Further, detecting and regulating their concentrations in both input streams and receiving environments, along with the removal processes of this specific class of emerging compounds, in the direction of developing a management policy is comprehensively reviewed.

Application of Hollow Fibre-Liquid Phase Microextraction Technique for Isolation and Pre-Concentration of Pharmaceuticals in Water

In this article, a comprehensive review of applications of the hollow fibre-liquid phase microextraction (HF-LPME) for the isolation and pre-concentration of pharmaceuticals in water samples is presented. HF-LPME is simple, affordable, selective, and sensitive with high enrichment factors of up to 27,000-fold reported for pharmaceutical analysis. Both configurations (two- and three-phase extraction systems) of HF-LPME have been applied in the extraction of pharmaceuticals from water, with the three-phase system being more prominent. When compared to most common sample preparation techniques such as solid phase extraction, HF-LPME is a greener analytical chemistry process due to reduced solvent consumption, miniaturization, and the ability to automate. However, the automation comes at an added cost related to instrumental set-up, but a reduced cost is associated with lower reagent consumption as well as shortened overall workload and time. Currently, many researchers are investigating ionic liquids and deep eutectic solvents as environmentally friendly chemicals that could lead to full classification of HF-LPME as a green analytical procedure.

A Bayesian Regularized Artificial Neural Network for Simultaneous Determination of Loratadine, Naproxen and Diclofenac in Wastewaters

Background::

Simultaneous determination of medication components in pharmaceutical samples using ordinary methods have some difficulties and therefore these determinations usually were made by expensive methods and instruments. Chemometric methods are an effective way to analyze several components simultaneously.

Objective::

In this paper, a novel approach based on Bayesian regularized artificial neural network is developed for the determination of Loratadine, Naproxen, and Diclofenac in water using UV-Vis spectroscopy.

Methods:

A dataset is collected by performing several chemical experiments and recording the UV-Vis spectra and actual constituent values. The effect of a different number of neurons in the hidden layer was analyzed based on final mean square error, and the optimum number was selected. Principle Component Analysis (PCA) was also applied to the data. Other back-propagation methods, such as Levenberg-Marquardt, scaled conjugate gradient, and resilient backpropagation, were tested.

Results::

In order to see the proposed network performance, it was performed on two crossvalidation methods, namely partitioning data into train and test parts, and leave-one-out technique. Mean square errors between expected results and predicted ones implied that the proposed method has a strong ability in predicting the expected values.

Conclusion::

he results showed that the Bayesian regularization algorithm has the best performance among other methods for simultaneous determination of Loratadine, Naproxen, and Diclofenac in water samples.

Determination of Non-Steroidal Anti-Inflammatory Drugs in Animal Urine Samples by Ultrasound Vortex-Assisted Dispersive Liquid–Liquid Microextraction and Gas Chromatography Coupled to Ion Trap-Mass Spectrometry

A low solvent consumption method for the determination of non-steroidal anti-inflammatory drugs (NSAIDs) in animal urine samples is studied. The NSAIDs were extracted with CH2Cl2 by the ultrasound vortex assisted dispersive liquid–liquid microextraction (USVA-DLLME) method from urine samples, previously treated with β-glucuronidase/acrylsulfatase. After centrifugation, the bottom phase of the chlorinated solvent was separated from the liquid matrix, dried with Na2SO4, and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) + trimethylchlorosilane (TMCS) (99 + 1). After cooling at room temperature, the solution was concentrated under nitrogen flow, and 1 µL of solution was analyzed in gas chromatography/ion trap-mass spectrometry (GC-IT-MS). The enrichment factor was about 300–450 times and recoveries ranged from 94.1 to 101.2% with a relative standard deviation (RSD) of ≤4.1%. The USVA-DLLME process efficiency was not influenced by the characteristics of the real urine matrix; therefore, the analytical method characteristics were evaluated in the range 1–100 ng mL−1 (R2 ≥ 0.9950). The limits of detection (LODs) and limits of quantification (LOQs) were between 0.1 and 0.2 ng mL−1 with RSD ≤4.5% and between 4.1 and 4.7 ng mL−1 with RSD ≤3.5%, respectively, whereas inter- and intra-day precision was 3.8% and 4.5%, respectively. The proposed analytical method is reproducible, sensitive, and simple.

TiO2 nanoparticles and C-Nanofibers modified magnetic Fe3O4 nanospheres (TiO2@Fe3O4@C-NF): A multifunctional hybrid material for magnetic solid-phase extraction of ibuprofen and photocatalytic degradation of drug molecules and azo dye

Accurate sensitive analysis of drug ingredient substances in biological, pharmaceutical and environmental samples and removal of drug ingredient substances in environmental samples owngreat importance for sustaining viability. The realization of these processes using a single material offers significant advantages in terms of cost, time and ease of use. In this study, TiO₂ nanoparticles and C-Nanofibers modified magnetic Fe₃O₄ nanospheres (TiO₂@Fe₃O₄@C-NFs) synthesized as a multifunctional material employing a simple hydrothermal synthesis method. This innovative material was exploited in the magnetic solid-phase extraction (MSPE) method for the preconcentration of ibuprofen and photocatalytic degradation of antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), and azo dye. To our knowledge, no studies have been previously conducted using the same material as magnetic solid-phase extraction adsorbent and magnetically separable photocatalyst. The characterization of TiO₂@Fe₃O₄@C-NFs was carried out by XRD, FE-SEM, EDX and Raman techniques. The main analytical parameters affecting MSPE performance of ibuprofen such as pH, sorbent amount eluent type and volume and sample volume were optimized. The optimum values of the method were determined at the following parameters: pH 4.0, adsorbent amount 150 mg and eluent 2 mL of acetone. Ibuprofen analysis after MSPE was carried out using a high-performance liquid chromatography diode array detection system (HPLC-DAD). The photocatalytic degradation efficiencies of TiO₂@Fe₃O₄@C-NF hybrid material for probe-analytes reached 80-100% and the complete degradation attained within the range of 8-125 min under UV irradiation. Simple preparation, practical isolation from solutions, high efficiency, reproducibility, and sustainability are the main advantages of the TiO₂@Fe₃O₄@C-NFs for MSPE and photocatalytic degradation applications.

Green synthesis of magnetic carbon nanodot/graphene oxide hybrid material (Fe3O4@C-nanodot@GO) for magnetic solid phase extraction of ibuprofen in human blood samples prior to HPLC-DAD determination

In this study, a green production method was used to obtain magnetic carbon nanodot/graphene oxide hybrid material (Fe₃O₄@C-nanodot@GO) for the magnetic solid phase extraction (MSPE) of ibuprofen (IBU) in human plasma prior to HPLC-DAD determination. For the first time in the literature, Fe₃O₄@C-nanodot@GO hybrid material was synthesized and used as an adsorbent. C-nanodots were produced from pasteurized cow milk by using a simple and cheap hydrothermal method. After production of the C-nanodots and GO, Fe₃O₄@C-nanodot@GO hybrid material was fabricated in green solvent medium by using an one-step hydrothermal method. The method was based on the simple separation, preconcentration and analysis of ibuprofen by using MSPE-HPLC-DAD combination. The concentration changes of ibuprofen in human bloods against time were successfully monitored by using this combined method. For this purpose, blood samples were taken from volunteers at certain intervals after the administration of a certain dose of ibuprofen, and the MSPE method was used to monitor the concentration changes of ibuprofen in the blood samples. Experimental variables affecting the extraction efficiency of IBU such as sample solution pH, amount of adsorbent, extraction time, eluent type and volume were studied and optimized in the details. The characterization studies for the Fe₃O₄@C-nanodot@GO were carried out by X-ray diffraction spectrometry (XRD), Fourier transform infrared spectrometry (FT-IR), Raman spectrometry (Raman), energy dispersive x-ray (EDX), vibrating sample magnetometry (VSM) and scanning electron microscopy (SEM) techniques. Under the optimum experimental conditions, the limit of detection (LOD) was 8.0 ng mL^-1 and the recoveries at three spiked levels in human plasma were ranged from 91.0% to 95.0% with the relative standard deviation (RSD %) less than 4.0 % (n = 6). The results show that together use of MSPE with HPLC-DAD provides a simple and rapid analysis of ibuprofen in human plasma samples.

Multi-walled Carbon Nanotubes Reinforced into Hollow Fiber by Chitosan Sol-gel for Solid/Liquid Phase Microextraction of NSAIDs from Urine Prior to HPLC-DAD Analysis

Background:

The efficient analytical method for the analysis of nonsteroidal antiinflammatory drugs (NSAIDs) in a biological fluid is important for determining the toxicological aspects of such long-term used therapies.

Methods:

In the present work, multi-walled carbon nanotubes reinforced into a hollow fiber by chitosan sol-gel assisted-solid/ liquid phase microextraction (MWCNTs-HF-CA-SPME) method followed by the high-performance liquid chromatography-diode array detection (HPLC–DAD) was developed for the determination of three NSAIDs, ketoprofen, diclofenac, and ibuprofen in human urine samples. MWCNTs with various dimensions were characterized by various analytical techniques. The extraction device was prepared by immobilizing the MWCNTs in the pores of 2.5 cm microtube via chitosan sol-gel assisted technology while the lumen of the microtube was filled with few microliters of 1-octanol with two ends sealed. The extraction device was operated by direct immersion in the sample solution.

Results:

The main factors influencing the extraction efficiency of the selected NSAIDs have been examined. The method showed good linearity R2 ≥ 0.997 with RSDs from 1.1 to 12.3%. The limits of detection (LODs) were 2.633, 2.035 and 2.386 µg L-1, for ketoprofen, diclofenac, and ibuprofen, respectively. The developed method demonstrated a satisfactory result for the determination of selected drugs in patient urine samples and comparable results against reference methods.

Conclusion:

The method is simple, sensitive and can be considered as an alternative for clinical laboratory analysis of selected drugs.

Simultaneous magnetic dispersive micro solid phase extraction of valsartan and atorvastatin using a CMC-coated Fe3O4 nanocomposite prior to HPLC-UV detection: multivariate optimization

In this study, a sensitive, rapid, accurate and practical procedure is established for determination of atorvastatin and valsartan from human biological fluids by dispersive micro solid phase extraction (D-μ-SPE) combined with HPLC-UV detector.

An evaluation of crude palm oil (CPO) and tocotrienol rich fraction (TRF) of palm oil as percutaneous permeation enhancers using full-thickness human skin

The drawbacks associated with chemical skin permeation enhancers such as skin irritation and toxicity necessitated the research to focus on potential permeation enhancers with a perceived lower toxicity. Crude palm oil (CPO) is obtained by direct compression of the mesocarp of the fruit of the oil palm belonging to the genus Elaeis. In this research, CPO and tocotrienol-rich fraction (TRF) of palm oil were evaluated for the first time as skin permeation enhancers using full-thickness human skin. The in vitro permeation experiments were conducted using excised human skin mounted in static upright 'Franz-type' diffusion cells. The drugs selected to evaluate the enhancing effects of these palm oil derivatives were 5-fluorouracil, lidocaine and ibuprofen: compounds covering a wide range of Log p values. It was demonstrated that CPO and TRF were capable of enhancing the percutaneous permeation of drugs across full-thickness human skin in vitro. Both TRF and CPO were shown to significantly enhance the permeation of ibuprofen with flux values of 30.6 µg/cm² h and 23.0 µg/cm² h respectively, compared to the control with a flux of 16.2 µg/cm² h. The outcome of this research opens further scope for investigation on the transdermal penetration enhancement activity of pure compounds derived from palm oil.

NSAIDs Determination in Human Serum by GC-MS

Non-steroidal anti-inflammatory drugs (NSAIDs) are being widely consumed without medical prescription and are often the cause of intoxication, usually in young children. For this, there is a special need in their determination in routine toxicology analysis. As screening methods mainly focus on drugs of abuse (DOA) that are alkaline compounds in their majority, they are not optimized for acidic drugs, such as NSAIDs. Thus, more specific methods are needed for the detection and quantification of this class of drugs. In this study, the efficient extraction of NSAIDs from blood serum and their accurate determination is studied. Optimum pH extraction conditions were studied and thereafter different derivatization procedures for their detection. From the derivatization reagents used, N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% Trimethylchlorosilane (TMCS) was found to be the optimum choice for the majority of the examined NSAIDs; pH of 3.7 was selected as the most efficient for the extraction step. Herein the formation of the lactam of diclofenac was also thoroughly investigated. The developed Gas Chromatography-Mass Spectrometry (GC-MS) method had a run time of 15 min with the mass spectrometer operating in Electron Impact (EI) within the mass range of 40 to 500 amu. The method was linear with R2 above 0.991 and limits of quantitation (LOQ) ranging from 6 to 414 ng/mL. The intra-day accuracy and precision were found between 1.03%–9.79% and 88%–110%, respectively, and the inter-day accuracy and precision were between 1.87%–10.79% and 91%–113%. The optimum protocol was successfully applied to real clinical samples, where intoxication of NSAIDs was suspected.

Fabrication of calixarene-grafted bio-polymeric magnetic composites for magnetic solid phase extraction of non-steroidal anti-inflammatory drugs in water samples

Calixarene framework functionalized bio-polymeric magnetic composites (MSp-TDI-calix) were synthesized and utilized as magnetic solid-phase extraction (MSPE) sorbent for the extraction of non-steroidal anti-inflammatory drugs (NSAIDs), namely indoprofen (INP), ketoprofen (KTP), ibuprofen (IBP) and fenoprofen (FNP), from environmental water samples. MSp-TDI-calix was characterized by FT-IR, XRD, FESEM, EDX, VSM and BET analysis, and the results were compared with Sp-TDI and Sp-TDI-calix. To maximize the extraction performance of MSp-TDI-calix decisive MSPE affective parameters such as sorbent amount, extraction time, sample volume, type of organic eluent, volume of organic eluent, desorption time and pH were comprehensively optimized prior to HPLC-DAD determination. The analytical validity of the proposed MSPE method was evaluated under optimized conditions and the following figures of merit were acquired: linearity with good determination coefficient (R² ≥ 0.991) over the concentration range of 0.5–500 µg/L, limits of detection (LODs) ranged from 0.06–0.26 µg/L and limits of quantitation (LOQ) between 0.20–0.89 µg/L. Excellent reproducibility and repeatability under harsh environment with inter-day and intra-day relative standard deviations were obtained in the range of 2.5–3.2% and 2.4–3.9% respectively. The proposed method was successfully applied for analysis of NSAIDs in tap water, drinking water and river water with recovery efficiency ranging from 88.1–115.8% with %RSD of 1.6–4.6%.

In-line carbon nanofiber reinforced hollow fiber-mediated liquid phase microextraction using a 3D printed extraction platform as a front end to liquid chromatography for automatic sample preparation and analysis: A proof of concept study

A novel concept for automation of nanostructured hollow-fiber supported microextraction, combining the principles of liquid-phase microextraction (LPME) and sorbent microextraction synergically, using mesofluidic platforms is proposed herein for the first time, and demonstrated with the determination of acidic drugs (namely, ketoprofen, ibuprofen, diclofenac and naproxen) in urine as a proof-of-concept applicability. Dispersed carbon nanofibers (CNF) are immobilized in the pores of a single-stranded polypropylene hollow fiber (CNF@HF) membrane, which is thereafter accommodated in a stereolithographic 3D-printed extraction chamber without glued components for ease of assembly. The analytical method involves continuous-flow extraction of the acidic drugs from a flowing stream donor (pH 1.7) into an alkaline stagnant acceptor (20 mmol L^-1 NaOH) containing 10% MeOH (v/v) across a dihexyl ether impregnated CNF@HF membrane. The flow setup features entire automation of the microextraction process including regeneration of the organic film and on-line injection of the analyte-laden acceptor phase after downstream neutralization into a liquid chromatograph (LC) for reversed-phase core-shell column-based separation. Using a 12-cm long CNF@HF and a sample volume of 6.4 mL, linear dynamic ranges of ketoprofen, naproxen, diclofenac and ibuprofen, taken as models of non-steroidal anti-inflammatory drugs, spanned from ca. 5-15 µg L^-1 to 500 µg L^-1 with enhancement factors of 43-97 (against a direct injection of 10 µL standards into LC), and limits of detection from 1.6 to 4.3 µg L^-1. Relative recoveries in real urine samples ranged from 97% to 105%, thus demonstrating the reliability of the automatic CNF@HF-LPME method for in-line matrix clean-up and determination of drugs in urine at therapeutically relevant concentrations.

Ibuprofen loaded nano-ethanolic liposomes carbopol gel system: in vitro characterization and anti-inflammatory efficacy assessment in Wistar rats

The objective of the present study was to develop and characterize nano-ethanolic liposomes (NEL) for transdermal delivery of ibuprofen (IBU). The NEL for transdermal delivery of IBU were prepared by thin film hydration technique and evaluated for vesicle size, shape, entrapment efficiency, transdermal flux, and in vivo anti-inflammatory activity in Wistar rats. The NEL optimized formulation (NEL-Opt) presented vesicle sizes of 32.85±1.98 nm and entrapment efficiency of 86.40±0.55% with improved transdermal flux. The presence of ethanol and flexibility of NEL could be the reasons for better permeation enhancement of IBU via rat’s skin. In vivo anti-inflammatory study of IBU-loaded NEL-Opt gel showed significant reduction (41.18%) of edema in carrageenan-induced rat paw edema as compared to conventional gel of IBU, where reduction of edema was found to be 12.50%. Our results suggest that developed NEL formulations are efficient systems for transdermal IBU delivery against inflammation. The stability study confirmed that the NEL-Opt gel formulation was considerably stable at refrigerator temperature. Our results concluded that NEL are an efficient carrier for transdermal delivery of IBU.

Salicylic acid determination in estuarine and riverine waters using hollow fiber liquid-phase microextraction and capillary zone electrophoresis

A low-cost methodology using hollow fiber liquid-phase microextraction (HF-LPME) and capillary zone electrophoresis (CZE) with UV-Vis detector was developed to analyze the salicylic acid (SA) in estuarine and riverine waters. The technique is easy-to-use and rapid, and demands little volume of organic solvent. The extraction was carried out using a polypropylene membrane supporting into octan-1-ol. HF-LPME under optimized conditions (donor solution sample pH 2, acceptor solution pH 14, sample volume 25 mL, fiber length 10 cm, acceptor volume 25 μL, extraction time 3 h and stirring speed 350 rpm) presented high enrichment factor (407 times) and good recovery in real water samples (from 88 to 110%). A limit of detection of 2.6 μg L^-1 was achieved using CZE with UV-Vis detector as quantification method. The method was applied to direct quantification of SA in environmental complex estuarine and riverine water matrices.