Photodiode Array Detector Research Articles

An eco-friendly HPLC method for concurrent determination of carbocisteine, guaifenesin, and oxomemazine in their combined formulations

The respiratory tract infections have a growing concern by healthcare specialists. Carbocisteine, guaifenesin, and oxomemazine are widely used as co-formulated anti-cough drugs. For the first time, a precise, accurate, and green HPLC method has been developed and validated for their determination in their combined dosage forms. The separation was accomplished using a photodiode array detector at 220 nm with an isocratic green mobile phase consisting of phosphate buffer 0.025 M, (pH 3) and ethanol (75:25, v/v) at a flow rate of 1.0 mL/min and ambient temperature. The developed method was validated in accordance with ICH guidelines. Carbocisteine, guaifenesin, and oxomemazine were separated in less than 12 min at 1.569 ± 0.005 min, 8.546 ± 0.007 min, and 10.877 ± 0.008 min, respectively. The linear ranges for carbocisteine, guaifenesin, and oxomemazine were 31.25–187.50, 25–150, and 0.5–3.0 µg/mL, respectively. The developed method can be used in quality control laboratories for the simultaneous determination of the investigated drugs in their pharmaceutical dosage forms. In addition, it proved its superiority over the reported methods in terms of greenness using different assessment tools.

Metabolites of Geum aleppicum and Sibbaldianthe bifurca: Diversity and α-Glucosidase Inhibitory Potential.

α-Glucosidase inhibitors are essential in the treatment of diabetes mellitus. Plant-derived drugs are promising sources of new compounds with glucosidase-inhibiting ability. The Geum aleppicum Jacq. and Sibbaldianthe bifurca (L.) Kurtto & T.Erikss. herbs are used in many traditional medical systems to treat diabetes. In this study, metabolites of the G. aleppicum and S. bifurca herbs in active growth, flowering, and fruiting stages were investigated using high-performance liquid chromatography with photodiode array and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PDA-ESI-tQ-MS/MS). In total, 29 compounds in G. aleppicum and 41 components in S. bifurca were identified including carbohydrates, organic acids, benzoic and ellagic acid derivatives, ellagitannins, flavonoids, and triterpenoids. Gemin A, miquelianin, niga-ichigoside F1, and 3,4-dihydroxybenzoic acid 4-O-glucoside were the dominant compounds in the G. aleppicum herb, while guaiaverin, miquelianin, tellimagrandin II2, casuarictin, and glucose were prevailing compounds in the S. bifurca herb. On the basis of HPLC activity-based profiling of the G. aleppicum herb extract, the most pronounced inhibition of α-glucosidase was observed for gemin A and quercetin-3-O-glucuronide. The latter compound and quercetin-3-O-arabinoside demonstrated maximal inhibition of α-glucosidase in the S. bifurca herb extract. The obtained results confirm the prospects of using these plant compounds as possible sources of hypoglycemic nutraceuticals.

Physicochemical stability of ready-to-administer mitomycin C solutions for intravesical instillation

ObjectiveThe aim of the study was to investigate the physicochemical stability of mitomycin-containing medicinal products for bladder instillation, formulated with urea as excipient (mito-medac®, Mitomycin medac). For comparison, the stability...

Portable Instruments Based on NIR Sensors and Multivariate Statistical Methods for a Semiautomatic Quality Control of Textiles

Near-infrared (NIR) spectroscopy is a widely used technique for determining the composition of textile fibers. This paper analyzes the possibility of using low-cost portable NIR sensors based on InGaAs PIN photodiode array detectors to acquire the NIR spectra of textile samples. The NIR spectra are then processed by applying a sequential application of multivariate statistical methods (principal component analysis, canonical variate analysis, and the k-nearest neighbor classifier) to classify the textile samples based on their composition. This paper tries to solve a real problem faced by a knitwear manufacturer, which arose because different pieces of the same garment were made with “identical” acrylic yarns from two suppliers. The sweaters had a composition of 50% acrylic, 45% wool, and 5% viscose. The problem occurred after the garments were dyed, where different shades were observed due to the different origins of the acrylic yarns. This is a challenging real-world problem for two reasons. First, there is the need to differentiate between acrylic yarns of different origins, which experts say cannot be visually distinguished before garments are dyed. Second, measurements are made in the field using portable NIR sensors rather than in a controlled laboratory using sophisticated and expensive benchtop NIR spectrometers. The experimental results obtained with the portable sensors achieved a classification accuracy of 95%, slightly lower than the 100% obtained with the high-performance laboratory benchtop NIR spectrometer. The results presented in this paper show that portable NIR sensors combined with appropriate multivariate statistical classification methods can be effectively used for on-site textile quality control.

Rapid high performance liquid chromatography method for erlotinib quantification in vitro: Application to study the effect of resveratrol on metabolism and cellular uptake of erlotinib.

Erlotinib is a selective epidermal growth factor receptor inhibitor that is used for the treatment of non-small cell lung cancer and pancreatic cancer. Its metabolism is mainly mediated by cytochrome P450 3A (CYP 3A). Resveratrol, a natural compound found in many plants and supplements, is known to inhibit CYP3A enzyme, therefore, it may act as an inhibitor for the metabolism of erlotinib. Development of a rapid high performance liquid chromatography with photodiode array detection (HPLC-PDA) method for the quantification of erlotinib in liver microsomes and cancer cells and its application to study resveratrol effect on metabolism and cellular uptake of erlotinib. HPLC-PDA was used to develop an efficient bioanalytical method with a 2.5-min runtime preceded by a simple protein precipitation step. The method was validated according to the European Medicines Agency guidelines. Erlotinib metabolic stability and resveratrol effect on erlotinib metabolite formation were evaluated in rat liver microsomes. Furthermore, the method was used to measure the intracellular concentrations of erlotinib in cancer colorectal cells and investigating resveratrol effect on the cellular uptake of erlotinib. A rapid HPLC-PDA method was developed and validated for the first time to address potential drug interaction of erlotinib with resveratrol. Resveratrol was a strong inhibitor of erlotinib metabolism in vitro with IC50 = 4.03 μM. Resveratrol, however, had no effect on erlotinib cellular uptake after 1h incubation in human colorectal cancer cells. The study suggests that resveratrol may produce a potential herb-drug interaction with erlotinib at the metabolism level and should be investigated in patients in the clinic.

Correlations of flavonoids content and antioxidant activity in bee honey from Bosnia and Herzegovina

In this study, it was performed identification and quantification of flavonoids (apigenin, chrysin, hesperetin, kaempferol, luteolin, naringenin, and quercetin) and flavonoid glycosides (rutin and vitexin) in total 49 samples of five different honey types from Bosnia and Herzegovina: meadow honey (MH, 22 samples), forest (FH, 10), acacia (AH, 7), chestnut (CH, 5), and heather honey (HH, 5). Additionally, evaluation of correlations between FC and total hydrophilic antioxidant score (antioxidant activity against both: ROO· + OH·) in supernatants (s) and in bulk (noncentrifuged) solution (b) of these honey types was performed. Moreover, correlations between flavonoids content (FC) and previously reported antioxidant activity against both peroxyl and hydroxyl free radicals (AC(ROO·) and AC(OH·)) for the same honey samples was examined. High performance liquid chromatography with photodiode array detector (HPLC-DAD) and isocratic elution mode was used as method of analysis. Flavonoids were extracted by solid phase extraction (SPE). The average contents of three flavonoids (chrysin, naringenin, and luteolin) in MH were statistically higher than in AH (p**<0.01). Also, the average content of naringenin in FH was statistically higher than in CH (p*<0.05). We observed a high (positive) linear correlation between FC and AC(ROO·) in s of four honey types (FH, AH, HH, CH) (R2=0.920). If we correlate FC and AC(ROO·)s of three honey types (FH, AH, HH), linearity is very high (R2=0.968), and for FH, AH, CH linearity is complete. The correlation between FC and AC(ROO·) in b of the same honey types is similar, but lower. The correlation does not exist between FC and AC(OH·) neither in s nor in b of five or four honey types, but for FC to both (AC(OH·)s and AC(OH·)b) of three honey types (FH, AH, CH), linearity is moderate (R2=0.732 and R2=0.696, respectively). Keywords: antioxidant activity, correlations, flavonoids, honey, HPLC-DAD.

Dissipation Kinetics of Imidacloprid and Thiamethoxam in a Sweet Lime Orchard Soil Near Pulivendula using Ultra-Hplc Coupled with a Photodiode Array Detector (PDA)

Imidaclopride (IMI) and Thiamethoxam (THI) were the neonicotinoids that were most frequently used in Andhra Pradesh in sweet lime orchards to control Helicoverpa armigera and Marucavitrata. Despite the frequent use of these insecticides, little is known about their behaviour and interaction in the soils of sweet lime orchards. The main objective of this study is to estimate the degradation of IMI and THI in soils from sweet lime orchards collected in and around Pulivendula, near Kadapa, using established kinetic models. A new, rapid, sensitive, precise, and validated "Ultra High Performance Liquid Chromatography Coupled with a Photodiode Array Detector" (UHPLC-PDA) is developed for the quantification of IMI and THI individually in agricultural soil samples by the QuEChERS extraction technique. The IMI and THI were sprayed on the sweet lime trees at a rate of 2 ml/l and 1.5 ml/l respectively. Soil samples were collected for analysis at 0 (within 1 hour), 1, 3, 5, and 10days time intervals after spraying on soil soils. Quantification was carried out utilizing a 40:60 (v/v) methanol/water mobile phase and a validated reverse-phase HPLC with a "PDA" detector at 272nm wavelength. Within the measured range of 0.05 to 1 ppm concentration, the calibration graphs of IMI and THI in methanol solvent were linear with an index of correlation greater than 0.996. Sprayed soil recovery ranges from 95% to 110% respectively, in respect of IMI and THI. The dissipation kinetics of IMI and THI was studied in logarithmic first-order kinetic models, for which the R2 was 0.948 and 0.997 respectively. The IMI residues were 1.91, 0.45, 0.31,

The Assessment of the Skin-Whitening and Anti-Wrinkling Effects of Anemarrhena asphodeloides Bunge Root Extracts and the Identification of Nyasol in a Developed Cream Product

Anemarrhena asphodeloides Bunge (A. asphodeloides Bunge) root extract contains nyasol as its main ingredient. Nyasol was extracted and prepared as a cosmetic raw material in 95% ethanol. To identify nyasol as a marker compound qualitative analysis was performed using ultra-performance liquid chromatographyi coupled with electrospray ionization–tandem mass spectrometry. Below a nyasol content of 12 μg/mL, the root extract exhibited negligible cytotoxicity. In this concentration range, melanin production in B16F10 mouse melanoma cells decreased as the concentration of nyasol increased, indicating a skin-whitening effect. In addition, an antiwrinkling effect was confirmed by evaluating the inhibition of MMP-1 protein expression in TNF-α-treated HaCaT cells by either A. asphodeloides Bunge root extract (>0.31 μg/mL) or nyasol (>0.25 μg/mL). High-performance liquid chromatography-coupled with a photodiode detector array was used to show that our extract contained 5.06 ± 0.01% nyasol. Furthermore, when this analysis method was applied for the quality control of a cream product containing 2 wt.% of A. asphodeloides Bunge root extract, the measured content of nyasol (0.1%) was over 90% of the nominal quantity. Therefore, the product was deemed to be within the required quality standards.

Tyrosinase Inhibition Activities of Depsides Isolated from Ramalina Species

Three depsides, namely sekikaic acid (1), homosekikaic acid (2), and 4′-O-demethylsekikaic acid (3) were isolated from acetone fraction of Ramalina spp. The structures were characterized by using spectroscopic techniques like 1H NMR, 13C NMR, ESI MS and IR. The quantitative determinations of these compounds were conducted by reversed phase high performance liquid chromatography with photodiode array detector (LC-PDA). The developed assay method could be considered as a suitable quality control method for Ramalina spp. The content on percentage dry basis of these compounds were 1.39%, 0.98% and 0.58% for compound 1, 2 and 3, respectively. It is the first time report for tyrosinase inhibition activity for depsides. All of these compounds exhibited inhibition for tyrosinase enzyme with the IC50 values 110.3±3.5, 90.1±1.4, and 206.4±5.1 µg/mL by the compounds 1, 2 and 3, respectively. The structure activity relationship of despides showed that the methoxy group at ring A might have enhanced the inhibitory activity. Therefore, these compounds may have their potential use in cosmetics with further studies.

Hogweed Seed Oil: Physico-Chemical Characterization, LC-MS Profile, and Neuroprotective Activity of Heracleum dissectum Nanosuspension.

The seeds of dissected hogweed (Heracleum dissectum Ledeb., Apiaceae) are the source of hogweed oil (HSO), which is still underexplored and requires careful chemical and biological studies. The performed physico-chemical analysis of HSO elucidated basic physical characteristics and revealed the presence of fatty acids, essential oil components, pigments, and coumarins. High-performance liquid chromatography with photodiode array detection and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PDA-ESI-tQ-MS/MS) identified 38 coumarins that were characterized and quantified. Various furanocoumarins were the major components of HSO polyphenolics, including imperatorin, phellopterin, and isoimperatorin, and the total coumarin content in HSO varied from 181.14 to 238.42 mg/mL. The analysis of storage stability of the selected compounds in HSO indicated their good preservation after 3-year storage at cold and freezing temperatures. The application of the CO2-assisted effervescence method allowed the production of an HSO nanosuspension, which was used in a brain ischemia model of rats. The HSO nanosuspension enhanced cerebral hemodynamics and decreased the frequency of necrotic processes in the brain tissue. Thus, H. dissectum seeds are a good source of coumarins, and HSO nanosuspension promotes neuroprotection of the brain after lesions, which supports earlier ethnopharmacological data.

HPLC methods for studying pharmacokinetics of tivozanib and in vitro metabolic interaction with dexamethasone in rat

Tivozanib is a recently approved tyrosine kinase inhibitor for the treatment of renal cell carcinoma. In this work, two new HPLC methods coupled with fluorescence (FLD), or photodiode array detectors (PDA) were developed and used for the first time for tivozanib quantification in rat plasma and liver microsomes. The described methods were efficient with a 4-min runtime employing a Gemini-NX C18 column (50 × 2.1 mm, 3 µm) and a mobile phase of acetonitrile and ammonium acetate buffer (pH 4.7, 10 mM) (40:60, v/v) delivered at a flow rate of 0.4 mL/min. The use of HPLC-FLD allowed the quantification of 50 ng/ mL tivozanib using only 100 µL rat plasma. The HPLC-FLD method was validated according to the US food and drug administration (FDA) bioanalytical guidelines and was applied successfully in a rat pharmacokinetic study (n = 7) following oral administration of 1 mg/ kg tivozanib. Furthermore, HPLC-PDA was used for monitoring the depletion of 1 μM (454.9 ng/mL) tivozanib in rat liver microsomes and was applied to study the effect of dexamethasone induction on tivozanib metabolism in vitro. Results showed that dexamethasone enhanced the intrinsic clearance of tivozanib by 60 % suggesting a potential drug-drug interaction at the metabolism level. Dexamethasone is commonly used in the management of cancer disease and thus coadministration with tivozanib therapy may cause treatment failure in patients. The simplicity, speed and cost-effectiveness of the reported methods are ideal for supporting in vivo and in vitro tivozanib studies, including drug-drug interaction studies, particularly in bioanalytical labs lacking LC-MS/MS capabilities.

Ecofriendly stability-indicating UHPLC-PDA method for determination of the new influenza antiviral prodrug Baloxavir Marboxil; application to degradation kinetic studies and structure elucidation of the major degradation products using LC-MS

Implementation of green chemistry principles in analytical procedures is of great importance. Green analytical chemistry minimizes the dangerous impact on human beings and the environment that is the primary objective nowadays. In the proposed work, a well-developed, fully validated and ecofriendly stability indicating UHPLC coupled with photodiode array detector (PDA) method was established for the determination of Baloxavir Marboxil (BXM), a novel antiviral drug for the treatment of influenza A and B, in raw materials and pharmaceutical formulations. The method employed Inertsil ODS-3 C18 column to separate BXM from its forced degradation products using a mobile phase composed of 0.1% citric acid (pH 2.5 ± 0.05)-methanol (50:50, v/v), at a flow rate of 0.8 mL/min in an isocratic separation mode. BXM was monitored using diode array detector at 260.0 nm. BXM stability was inspected using various stress conditions as per ICH recommendations. The impact of acid, base hydrolysis, and oxidative stress conditions was greater on BXM in comparison to photo and thermal hydrolysis. The formed degradation products were injected into the mass spectrometer (MS) to elucidate their structures. The suggested pathways for degradation mechanisms were presented. Moreover, the proposed method was effectively utilized to study the degradation kinetics of acid, base and oxidative degradation of BXM. Additionally, four assessment tools were employed to evaluate the greenness of the developed method, namely; the National Environmental Method Index, the Analytical Eco-scale, Green Analytical Procedure tool, and the Analytical Greenness metric. Moreover, a comparative study of the method's greenness was conducted with the reported HPLC method and the results confirming that the suggested method is superior regarding the guidelines and principles of green chemistry. In addition to, having higher qualitative and quantitative scores in comparison to the reported method, and providing reliable and precise results of the method greenness.

Development and Validation of Robust, Highly Sensitive and Stability-Indicating RP-HPLC Method for Estimation of Deferasirox and its Degradation Products.

A rapid, simple and highly sensitive stability-indicating reverse-phase high-performance liquid chromatographic technique, coupled with a photodiode array detector, was developed and validated for the estimation of Deferasirox (DFS). The chromatographic separation was achieved using a C-18 (250 × 4.6 mm, 5μm) stationary phase and a mobile phase composed of 0.1% orthophosphoric acid and acetonitrile at a flow rate of 1mL/min. The detection was carried out at a wavelength of 245nm with a constant injection volume of 10μL throughout the analysis. With an R2 value of 0.9996, the calibration curve was determined to be linear over an appropriate concentration range of 50-500ng/mL. According to the International Conference on Harmonization (ICH) Q1 (R2) guideline, DFS was evaluated under stress conditions that included hydrolytic (acid, alkali and neutral), oxidative and thermal degradation. The findings demonstrated that significant degradation was observed in acidic degradation conditions, whereas drug substance was found to be stable when exposed to neutral, basic, oxidative and thermal degradation. The developed method was validated as per ICH guidelines. The developed method was employed successfully to estimate the amount of DFS in bulk and pharmaceutical formulation.

Statistical Medium Optimization for the Production of Anti-Methicillin-Resistant Staphylococcus aureus Metabolites from a Coal-Mining-Soil-Derived Streptomyces rochei CMB47

The development of novel antibacterial drugs needs urgent action due to the global emergence of antibiotic resistance. In this challenge, actinobacterial strains from arid ecosystems are proving to be promising sources of new bioactive metabolites. The identified Streptomyces rochei strain CMB47, isolated from coal mine Saharan soil, provided an ethyl acetate extract which tested against a series of pathogens. It displayed a minimum inhibitory concentration of <0.439 µg/mL against MRSA. A statistical experimental design using a response surface methodology (RSM) based on the second-order rotatable central composite design (RCCD) was planned to develop an efficient fermentation process able to improve the bioactive metabolite production. The optimal conditions were determined for starch and NaNO3 concentrations, incubation time and the initial pH value, reaching the inhibition zone diameter of 20 mm, close to the experimental value, after validation of the model. A bioassay-guided fractionation of the crude extract provided the most active fractions, which were analyzed by HPLC equipped with a photodiode array detector and coupled online with an electrospray mass spectrometer (HPLC-DAD/ESI-MS), obtaining preliminary indications on the molecular structures of the metabolites. These results support the potential interest in further investigations into the purification and full characterization of the metabolites responsible for the biological activity observed so far.

Simultaneous quantification of (E) and (Z) isomers of rilpivirine and four degradation products in bulk and tablets by reversed-phase ultra-high-performance liquid chromatography and confirmation of all by molecular weight.

The (E)-isomer of rilpivirine is an approved antiretroviral drug used to treat human immunodeficiency virus. A simple, fast, accurate, and precise analytical method is required to confirm the quality, purity, efficacy, and safety of drug substances and drug products containing rilpivirine. This research article offers a comprehensive ultra-high performance liquid chromatography method for the simultaneous separation and quantification of (E) and (Z) isomers of rilpivirine, including two amide impurities, one nitrile impurity, and one dimer impurity, in both bulk and tablet forms. After complete validation, the proposed reversed-phase ultra-high-performance liquid chromatography method has proven to be simple, fast, linear, accurate, and precise, with a lower limit of quantification and detection of 0.05 and 0.03μg/ml, respectively, for all six analytes. Separation was achieved on a Waters Acquity ethylene bridged hybrid Shield RP18 (150×2.1mm, 1.7μm) column maintained at 35.0°C using a gradient elution of acetonitrile and 0.05% formic acid in 10mM ammonium formate at a flow rate of 0.30ml/min. A systematic forced degradation study on the undissolved rilpivirine revealed the formation of acid-base hydrolyzed amide impurities (Impurity-A and Impurity-B), oxidative nitrile impurities (Impurity-C), and Z-isomer and dimer impurities of rilpivirine (Impurity-D and Impurity-E) due to alkaline hydrolysis and photodegradation. The proposed method is primarily appropriate for applications requiring the precise determination of desired and undesired isomers of rilpivirine and its degradation products, such as those involving the safety, efficacy, and quality roles of rilpivirine in bulk and tablet forms. Additionally, the proposed ultra-high-performance liquid chromatography method in combination with a mass spectrometer and photo-diode array detector is helpful for the confirmation and correct identification of all analytes.

Sensitive determination of polybrominated diphenyl ethers (PBDEs) in water and milk by effervescence-enhanced switchable hydrophilic-hydrophobic solvent-based salting-out microextraction and high-performance liquid chromatography with photodiode array detection (HPLC-PDA)

Here is reported effervescent reaction-enhanced switchable hydrophilic-hydrophobic solvent-based salting-out microextraction (ERSSM) with high-performance liquid chromatography with photodiode array detection (HPLC-PDA) for the preconcentration, extraction, and trace-level determination of polybrominated diphenyl ethers (PBDEs) in milk and water. The important variables were rigorously optimized to be 150 µL of hexanoic acid as the extraction solvent, 400 µL of Na2CO3 as the alkaline source, 350 µL of H2SO4 solution as the acid source, and NaCl as the salting-out agent. The optimized conditions provided a linear range from 0.2 to 50 µg L−1 with limits of detection and quantitation from 0.026 to 0.085 µg L−1 and 0.087 to 0.28 µg L−1 for six PBDEs. The intra-day and inter-day precision values were from 2.48% to 6.75%, and the fortified recoveries for PBDEs were between 78.06% and 103.07% in water and milk samples. The developed procedure avoids the use of a traditional organic disperser and mechanical mixing allowing the determination of PBDEs outdoors by synchronous extraction method and high efficiency for the analytes. These advantages suggest a high potential for the routine monitoring of PBDEs in liquid food and environmental samples.

Development and Validation of HPLC–Photodiode Array Method for Detecting Steroids in Skin Whitening Products Simultaneously

Since steroids are prohibited to be present in cosmetic products, thus an identification of these outlawed compounds intentionally incorporated in skin whitening product is enough for market surveillance purpose. Simultaneous method for detecting prednisone (PRN), triamcinolone acetonide (TCA), hydrocortisone acetate (HCA), clobetasole propionate (CBP), and mometasone furoate (MTF) has not been developed until now. The goals of this study were to develop and to validate for screening these five steroid compounds in cosmetic product by using reverse phase (RP) high-performance liquid chromatography (HPLC) equipped with photo diode array (PDA) detector. Validation method was applied including the system suitability test, determination of specificity and selectivity, and determination of detection limit. . In optimization step, we succeeded distinguish and identify five steroid compounds with different retention time.The retention times of PRN, TCA, HCA, CBP and MTF were detected at 3.267, 4.260, 4.910, 15.360, and 16.707 min, respectively. The method performed good selectivity with resolution more than 1.5. While for determination of limit of detection (LOD) was carried out by calibration curve approach over the range 0.5-5 µg/ml and resulted in LOD value for PRN, TCA, HCA, CBP and MTF were 7.20, 8.85, 8.17, 9.30, and 8.42 µg/g, respectively. The developed method can be applied for routine analysis of PRN, TCA, HCA, CBP and MTF in various type of cosmetic products.

Methods optimization and application: Solid phase extraction, ultrasonic extraction and Soxhlet extraction for the determination of antiretroviral drugs in river water, wastewater, sludge, soil and sediment

The continuous release of antiretroviral drugs into the environmental has resulted in the interest to assess their occurrence in various environmental matrices. Their presence has led to antiretroviral drugs being considered the pollutants of concern due to their possible alterations of the ecosystem as well as the antiviral resistance that may develop upon their unintentional consumption. Therefore, in this work, solid phase extraction (SPE), ultrasonic extraction (UE), Soxhlet extration (SE) and liquid chromatography coupled to photodiode array detector (LC-PDA) methods have been optimized and validated. They were then applied for the simultaneous determination of abacavir, nevirapine and efavirenz antiretroviral drugs in wastewater, river water, sludge, soil and sediments. The percentage recoveries ranged from 71% to 112% for SPE, 88 – 108% for SE and 61 – 104% for UE. Good precision with a relative standard deviation less than 20% in all compounds for all methods was obtained. The LODs and LOQs ranged between 0.68 and 0.77 µg/L and 2.1–2.4 µg/L for SPE; 0.8–0.9 µg/kg and 2.3–2.8 µg/kg for SE and 1.6–2.8 µg/kg and 4.9 – 7.0 µg/kg for UE, respectively. The concentrations ranged from <lod - 102 µg/L, <lod – 814 µg/L, and <lod – 6759 µg/L, <lod − 138 µg/g, <lod - 98.9 µg/g, in river water, wastewater, sludge, soil and sediment samples, respectively. Abacavir was dominant in water while efavirenz was dominant in soil/sediments. The results showed that SE is more sensitive and more accurate than UE, hence it can be recommended for routine analysis despite its longer extraction times. The percentage removal efficiency ranged from 44% to 87% for nevirapine, 6–53% for efavirenz, and 75–91% for abacavir which indicates that these compounds were not completely removed during the WWTP processes, hence they ended up in river waters.

Multicomponent antihypertensive pharmaceuticals determination with related impurity analysis using MEKC: Whiteness and greenness assessment

In the present study, a white and green micellar electrokinetic chromatography method (MEKC) coupled with a photo diode array detector (DAD) has been established for challenging multi-component analysis of two antihypertensive combinations therapy. The first one is the supramolecular complex LCZ696 of valsartan (VAL) and sacubitril (SAC) with sacubitril related impurity (BMP) and the second combination is nebivolol (NEB) with thiazide like diuretics: hydrochlorothiazide (HCZ) and indapamide (IND). Separation was done using fused silica capillary (40 cm × 50 μm id) along with 10 mM phosphate buffer adjusted to pH 10 in presence of 25 mM sodium dodecyl sulphate (SDS). Linearity was assessed in the concentration ranges of 10–300, 10–300, and 5–50 μg. mL−1 for VAL, SAC, and BMP (Mix I) respectively, while for Mix II 20–200 μg. mL−1 for HCZ, IND and NEB with r > 0.9991. LOD were 3.12,3.11 and1.53 μg. mL−1for VAL, SAC, and BMP respectively. In addition, LOD for Mix II were 5.92,4.44 and 5.30 μg. mL−1for HCZ, IND and NEB respectively. The applicability of the suggested method was proved by investigating the five antihypertensive drugs at various concentrations levels in different pharmaceutical preparations with sacubitril related impurity analysis,BMP,at minute level in presence of parent drug, SAC, reaching 1.6%. Moreover, the proposed method did not rely only on the greenness evaluation tool using the most widely used Analytical Eco-Scale and the novel AGREE tool but also was merged with whiteness appraisal using RGB 12 algorithm.

Comparison of Different Green Extraction Techniques Used for the Extraction of Targeted Flavonoids from Edible Feijoa (Acca sellowiana (O.Berg) Burret) Flowers

This study aimed to investigate the effect of four green extraction techniques (ultrasound-assisted extraction, UAE; supercritical fluid extraction, SFE; subcritical water extraction, SWE; and extraction using deep eutectic solvents, DES) on the extraction of targeted flavonoids from edible feijoa flowers. The bioactive components in the obtained extracts were quantified by High-Performance Liquid Chromatography-Photodiode Array Detector (HPLC-PDA). Moreover, total polyphenol content and antioxidant activity by DPPH•, ABTS•+, FRAP, and CUPRAC assays were investigated. UAE generally gave the highest yields for isoquercitrin and quercetin content (18.36-25.33 and 10.86-16.13 µg/g), while DES extraction with choline chloride:lactic acid (1:2) and H2O content of 50% gave the highest yield of chrysanthemin (90.81 µg/g). The highest yield of flavone (12.69 mg/g) was obtained with supercritical CO2 at 300 bar. Finally, UAE gave the highest total polyphenol content (ca. 64 mg GAE/g) and antioxidant activity at 70 °C during 30 min with 40% (0.84 mmol TEAC/g and 2.25 mmol Fe2+/g, for ABTS•+ and CUPRAC, respectively) and 60% ethanol-water solution (0.49 mmol TEAC/g and 2.09 mmol Fe2+/g, for DPPH• and FRAP, respectively). The eco-friendly extraction techniques resulted in selective methods capable of extracting targeted bioactive compounds from edible feijoa flowers.