Venlafaxine Research Articles

Enhanced degradation of venlafaxine induced by Fe2O3/CeO2 heterostructures through the thermal transformation from type I to direct Z-scheme in heterogeneous photo-Fenton

Heterostructures based on Fe2O3/CeO2 were synthesized by coprecipitating iron and cerium salts, with 70 % and 50 % atomic percentage of iron, and heat treatment at 600 and 800 °C (Fe70Ce600, Fe50Ce600, Fe70Ce800, Fe50Ce800). The catalytic activity in the Fenton and photo-Fenton process was evaluated in the degradation of venlafaxine (VEN) using UV/Vis LEDs. Treatment at 800 °C promoted greater crystallinity, increased crystallite size, decreased specific area, and high absorption between 200 and 600 nm, and bandgap energy (Eg) between 1.6 and 3.0 eV were observed. The heat treatment promoted different mechanisms in heterostructure materials with type I (straddling) schemes for Fe70Ce600 and Fe50Ce600, type II for Fe50Ce800, and direct Z for Fe70Ce800 responsible for generating a higher concentration of HO• radicals, high oxidation-reduction power (Fe2+/Fe3+) and (Ce4+/Ce3+), greater effective separation of charge carriers, providing improved catalytic activity due to the synergy between heterogeneous photocatalysis and photo-Fenton processes. LC-MS/MS analysis identified 12 transformation products (TPs), involving hydroxylation reactions, demethylation, and loss of cyclohexanol. The transformation products TP2 and TP9 were exclusive to Fe70Ce800, confirming different mechanisms among the heterostructures.

Formulation and Evaluation of Sustained Release Dosage Form of Venlafaxine Hydrochloride for Enhanced Treatment of Neurodisorders

In the present study, we have designed and developed a sustained-release tablet formulation of Venlafaxine Hydrochloride. The optimized formulation was then subjected to various evaluation parameters. The formulation of venlafaxine hydrochloride sustained release tablets with a dosage of 500 mg included the utilization of several hydrophilic polymers, including jackfruit mucilage, HPMC K4, and PVPK30, as release retardants. This was done to extend the duration of drug release to 12 hours. The formulation features, including pre-compression and post-compression investigations, were conducted individually according to established protocols. The tablets were determined to be compliant in terms of weight uniformity, hardness, thickness, diameter, friability, and drug content. Separate in-vitro dissolution studies were done for both tablets. The venlafaxine hydrochloride SR formulation F18 was optimized to provide the desired release profile for up to 12 hours. The Venlafaxine Hydrochloride SR formulation was optimized and exhibited zero-order release kinetics. The stability studies conducted under accelerated conditions at a temperature of 40 ± 2°C and a relative humidity of 75 ± 5% yielded good results. The study indicated that the sustained release administration of Venlafaxine HCl is potentially efficacious. It reduces the frequency at which the patient has to take medication and improves patient adherence. Our objective is to conduct in-vivo pharmacokinetic studies of the formulation to verify the drug’s entry into the systemic circulation.

Combination of low doses of mirtazapine plus venlafaxine produces antidepressant-like effects in rats, without affecting male or female sexual behavior.

Pharmacological treatments for depression are not always effective and produce unwanted side effects. Male and female sexual dysfunction is one of these side effects, which can lead to treatment withdrawal. Combination of two antidepressants with different mechanisms of action, like mirtazapine (MTZ) and venlafaxine (VLF) have been shown to be effective for treatment-resistant depression in humans. Combination of low doses of these drugs may still exert antidepressant-like effects without altering sexual behavior. To investigate the potential antidepressant-like effect of the chronic administration of low doses of MTZ plus VLF combined, as well as its impact on male and female sexual behavior in rats. The antidepressant-like effect of a 14-day treatment with combinations of MTZ plus VLF (0/0, 2.5/3.75 or 5/7.5mg/kg) was assessed in young adult male and female rats in the forced swim test (FST). The 5/7.5mg/kg MTZ/VLF combination was also tested in the chronic mild stress (CMS) test, in both males and females treated for 21days. The sexual effects of this last treatment were assessed in sexually experienced males and in gonadally-intact females during proestrus. The 5/7.5mg/kg MTZ/VLF combination produced an antidepressant-like effect in the FST and reversed the CMS-induced anhedonia in both male and female rats. This combination did not alter male sexual behavior, female proceptive and receptive behaviors or the regularity of the estrous cycle. The combination of low doses of MTZ and VLF might be a promising therapeutic alternative to treat depression without affecting the sexual response.

Design and evaluation of cost-effective oro-dispersible tablets of venlafaxine hydrochloride by effervescent method

Design and evaluation of cost-effective oro-dispersible tablets of venlafaxine hydrochloride by effervescent method

Pharmacokinetic Bioequivalence and Safety Assessment of Two Venlafaxine Hydrochloride Extended-Release Capsules in Healthy Chinese Subjects Under Fed Conditions: A Randomized, Open-Label, Single-Dose, Crossover Study.

Venlafaxine hydrochloride extended-release (ER) capsules are commonly used to treat depression and anxiety disorders. Evaluation of the bioequivalence of generic formulations with reference products is essential to ensure therapeutic equivalence. The objective of this study was to evaluate the bioequivalence, safety, and tolerability of Chinese-manufactured venlafaxine hydrochloride extended-release capsules compared with USA-manufactured EFFEXOR® XR in healthy Chinese volunteers under fed conditions. A randomized, open-label, single-dose, crossover study was conducted. Subjects were randomly assigned to receive the test formulation (one 150-mg ER capsule manufactured in China) or the reference formulation (one 150-mg ER capsule manufactured in the USA). The bioequivalence of the two drugs was assessed using the area under the plasma concentration-time curve from time zero to the last sampling time (AUC0-t) and the maximum observed concentration (Cmax). A total of 28 subjects were enrolled and randomly assigned to receive a single dose of either the test or reference capsule. All the subjects completed the study and were included in the pharmacokinetic (PK) and safety analyses. The mean AUC0-t and Cmax of venlafaxine and its active metabolite O-desmethylvenlafaxine were comparable between the test and reference products with both parameters close to 100% and the corresponding 90% confidence intervals within the specified 80-125% bioequivalence boundary. Safety was also assessed between the two products and all adverse events (AEs) in this study were mild in severity. Both the test and reference venlafaxine hydrochloride ER capsules were bioequivalent and showed a similar safety and tolerability profile in the population studied. This study was registered at the Drug Clinical Trial Registration and Information Publicity Platform ( http://www.chinadrugtrials.org.cn/index.html ) with registration number CTR20211243, date: June 1, 2021.

CYP2D6 Phenotype Influences Pharmacokinetic Parameters of Venlafaxine: Results from a Population Pharmacokinetic Model in Older Adults with Depression.

In this study, we aimed to improve upon a published population pharmacokinetic (PK) model for venlafaxine (VEN) in the treatment of depression in older adults, then investigate whether CYP2D6 metabolizer status affected model-estimated PK parameters of VEN and its active metabolite O-desmethylvenlafaxine. The model included 325 participants from a clinical trial in which older adults with depression were treated with open-label VEN (maximum 300 mg/day) for 12 weeks and plasma levels of VEN and O-desmethylvenlafaxine were assessed at weeks 4 and 12. We fitted a nonlinear mixed-effect PK model using NONMEM to estimate PK parameters for VEN and O-desmethylvenlafaxine adjusted for CYP2D6 metabolizer status and age. At both lower doses (up to 150 mg/day) and higher doses (up to 300 mg/day), CYP2D6 metabolizers impacted PK model-estimated VEN clearance, VEN exposure, and active moiety (VEN + O-desmethylvenlafaxine) exposure. Specifically, compared with CYP2D6 normal metabolizers, (i) CYP2D6 ultra-rapid metabolizers had higher VEN clearance; (ii) CYP2D6 intermediate metabolizers had lower VEN clearance; (iii) CYP2D6 poor metabolizers had lower VEN clearance, higher VEN exposure, and higher active moiety exposure. Overall, our study showed that including a pharmacogenetic factor in a population PK model could increase model fit, and this improved model demonstrated how CYP2D6 metabolizer status affected VEN-related PK parameters, highlighting the importance of genetic factors in personalized medicine.

Unexplained recurrent high fever observed in a depressed adolescent

BackgroundDepressive episodes in adolescents are often accompanied by various physical symptoms, but few studies have explored the association between depression and fever, This case study is the first to report the relationship between unexplained recurrent high fever and depression.Case presentationH is a 15 year old adolescent female currently in junior year. 2 + months ago, H gradually felt depressed after a class change. Around the time, the patient suddenly developed chills with no obvious trigger and fever. H was treated with anti-infective and anti-viral treatments all of which did not show significant improvement. No significant abnormality was seen in any of the related examinations. Considering that the patient’s anxiety, depression and somatic symptoms were obvious during the course of the disease, she was given venlafaxine hydrochloride extended-release capsule 75 mg/d; tandospirone citrate capsule 10 mg Bid; alprazolam tablets 0.4 mg qn to improve mood and sleep; supplemented with transcranial repetitive magnetic stimulation therapy 2 times/d; visible light therapy 1 time/d and psychological counseling once. Over the 6 days of treatment, the patient’s body temperature gradually returned to the normal range and her mood improved significantly.ConclusionDepression should be considered a potential cause of unexplained recurrent fevers in adolescents, even when the temperature is significantly outside the normal range.

Análisis retrospectivo de las hipoglucemias inducidas por venlafaxina en pacientes con sobredosis

IntroductionRecent publications relate the presence of hypoglycemia in venlafaxine (VLX) poisoning depending on the dose. Our aim was to analyze the clinical characteristics of patients who presented hypoglycemia induced by VLF overdose. Patients and methodsRetrospective study carried out in the Balearic Islands (2020–2023). Inclusion criteria: serum concentrations of VLX + O-desmethyl-venlafaxine (O-VLX)>800 ng/mL. The characteristics of patients with and without hypoglycemia were compared. ResultsTwenty-one patients were included, 8 (38.1%) with hypoglycemia. No differences were found in the doses referred to in both groups. Peak concentrations of VLX + O-VLX (ng/mL) were 9,783 [4,459–17,976] in patients with hypoglycemia and 1,413 [930–1,719] in patients without hypoglycemia (p<0.0001). The presence of hypoglycemia was associated with: lower age and level of consciousness; and higher frequency of suicide attempts, seizures, mydriasis, tachycardia and serotonin syndrome, invasive respiratory support, fluid therapy and ICU admission (p<0.05). ConclusionsThe detection of hypoglycemia in a VLX overdose case is a readily available marker to suspect the severity of the patient. In any case, serum concentrations when available allow us to confirm intoxication.

FeS2 nanosheets-luminol-O2 chemiluminescence method for determination of venlafaxine hydrochloride, imipramine hydrochloride, and cefazolin sodium.

This study introduces a novel chemiluminescence (CL) approach utilizing FeS2 nanosheets (NSs) catalyzed luminol-O2 CL reaction for the measurement of three pharmaceuticals, namely venlafaxine hydrochloride (VFX), imipramine hydrochloride (IPM), and cefazolin sodium (CEF). The CL method involved the phenomenon of quenching induced by the pharmaceuticals in the CL reaction. To achieve the most quenching efficacy of the pharmaceuticals in the CL reaction, the concentrations of reactants comprising luminol, NaOH, and FeS2 NSs were optimized accordingly. The calibration curves demonstrated exceptional linearity within the concentration range spanning from 4.00 × 10-7 to 1.00 × 10-3mol L-1, 1.00 × 10-7 to 1.00 × 10-4mol L-1, and 4.00 × 10-6 to 2.00 × 10-4mol L-1 with detection limits (3σ) of 3.54 × 10-7, 1.08 × 10-8, and 2.63 × 10-6mol L-1 for VFX, IPM, and CEF, respectively. This study synthesized FeS2 NSs using a facile hydrothermal approach, and then the synthesized FeS2 NSs were subjected to a comprehensive characterization using a range of spectroscopic methods. The proposed CL method was effective in measuring the aforementioned pharmaceuticals in pharmaceutical formulations as well as different water samples. The mechanism of the CL system has been elucidated.

Development and Evaluation of Venlafaxine Hydrochloride Tablets for Oral Drug Delivery Technology

Oral pills are the predominant, simple, and straightforward approach for administering drugs. The project’s primary goal is to create a pharmaceutical product that is equal in terms of its medicinal properties. A controlled-release version of the antidepressant venlafaxine hydrochloride was created and compared to the formulation currently available on the market. The launch of the branded product was assessed through an innovator and prototype evaluation. In order to develop stable and bioavailable dosage forms, it is necessary to gather pertinent data through preformulation testing. In order to create stable and bioavailable dosage forms, preformulation testing must be performed to gather relevant information among the several mixes, high-performance polymer copolymer K100M, ethyl cellulose, and cross-linked polyvinyl pyrrolidone 0.45%. The precise release mechanism could be determined by conducting in-vitro solubility tests on the created formulations and analyzing the results with a number of exponential equations. We used fourier-transform infrared (FTIR) and differential scanning calorimetry (DSC) studies to check if the polymers were compatible with the medicine.

Green innovation in analytical chemistry: A sustainable densitometric HPTLC approach for the distinctive separation and quantification of structurally related abused drugs - tramadol, tapentadol, and venlafaxine - in seized pharmaceutical dosage forms

An innovative ecofriendly high-performance thin layer chromatographic (HPTLC) method with spectrophotometric detection for simultaneous determination of Tramadol (TMD), Tapentadol (TAP), and Venlafaxine (VEN) in seized dosage forms was presented. Our method was conducted to achieve separation following the optimal conditions: pre-coated silica gel plates using a green mobile phase (heptane: acetone: ammonia, 7:3:0.5 v/v), with absorbance scanning at 272 nm. The validation of the method was done following International Conference on Harmonization (ICH) guidelines, demonstrates linearity, accuracy, precision, selectivity, robustness, and system suitability. Separation was achieved with a detection limit of 0.34, 0.16, and 0.084 (ug/band) for TMD, TAP, and VEN, respectively, the method successfully analyzes seized samples. Trueness is confirmed through a high degree of similarity between HPTLC and gas chromatography results. The study's ecofriendly approach, simplicity, and selectivity position it as a promising method for efficient, on-site monitoring of seized samples.

Physiologically Based Pharmacokinetic Modeling to Unravel the Drug-gene Interactions of Venlafaxine: Based on Activity Score-dependent Metabolism by CYP2D6 and CYP2C19 Polymorphisms.

Venlafaxine (VEN) is a commonly utilized medication for alleviating depression and anxiety disorders. The presence of genetic polymorphisms gives rise to considerable variations in plasma concentrations across different phenotypes. This divergence in phenotypic responses leads to notable differences in both the efficacy and tolerance of the drug. A physiologically based pharmacokinetic (PBPK) model for VEN and its metabolite O-desmethylvenlafaxine (ODV) to predict the impact of CYP2D6 and CYP2C19 gene polymorphisms on VEN pharmacokinetics (PK). The parent-metabolite PBPK models for VEN and ODV were developed using PK-Sim® and MoBi®. Leveraging prior research, derived and implemented CYP2D6 and CYP2C19 activity score (AS)-dependent metabolism to simulate exposure in the drug-gene interactions (DGIs) scenarios. The model's performance was evaluated by comparing predicted and observed values of plasma concentration-time (PCT) curves and PK parameters values. In the base models, 91.1%, 94.8%, and 94.6% of the predicted plasma concentrations for VEN, ODV, and VEN + ODV, respectively, fell within a twofold error range of the corresponding observed concentrations. For DGI scenarios, these values were 81.4% and 85% for VEN and ODV, respectively. Comparing CYP2D6 AS = 2 (normal metabolizers, NM) populations to AS = 0 (poor metabolizers, PM), 0.25, 0.5, 0.75, 1.0 (intermediate metabolizers, IM), 1.25, 1.5 (NM), and 3.0 (ultrarapid metabolizers, UM) populations in CYP2C19 AS = 2.0 group, the predicted DGI AUC0-96h ratios for VEN were 3.65, 3.09, 2.60, 2.18, 1.84, 1.56, 1.34, 0.61, and for ODV, they were 0.17, 0.35, 0.51, 0.64, 0.75, 0.83, 0.90, 1.11, and the results were similar in other CYP2C19 groups. It should be noted that PK differences in CYP2C19 phenotypes were not similar across different CYP2D6 groups. In clinical practice, the impact of genotyping on the in vivo disposition process of VEN should be considered to ensure the safety and efficacy of treatment.

Efficacy and safety of venlafaxine hydrochloride combined with tandospirone citrate for patients with vascular depression accompanied by somatic symptoms: An open-labeled randomized control trial.

To explore the pharmacological treatment of vascular depression (VaDep) and whether the blood levels of neurotransmitters can reflect the VaDep severity. VaDep patients with somatic symptoms were enrolled and randomly received venlafaxine + tandospirone (Combined Group) or venlafaxine (Monotherapy Group). The treatment efficacy was assessed by Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), and Patient Health Questionnaire-15 (PHQ-15). The levels of blood monoamine neurotransmitters were measured by enzyme-linked immunosorbent assay. Both groups reported a progressive decrease in HAMD, HAMA, and PHQ-15 scores to below the baseline after the respective treatment. Compared with the Monotherapy Group, the Combined Group reported a significant decrease in HAMD score at week 2 and markedly lower HAMA and PHQ-15 scores at weeks 1, 2, 4, and 8. Both groups showed a decrease in the levels of blood monoamine neurotransmitters at weeks 4 and 8 when compared with the baseline. A strong positive association was evident between the plasma 5-HT levels and the HAMD score. The combined therapy rapidly acts on VaDep comorbid with anxiety and somatic symptoms and significantly alleviates the anxiety and somatic symptoms. The plasma levels of 5-HT may serve as potential objective candidates in evaluating VaDep severity and the efficacy of the undertaken treatment regimen.

A Natural Language Processing Framework for Detecting Adverse Drug Reactions in Clinical Structured Drug Reviews

Background: Adverse drug reactions (ADRs) pose significant concerns in healthcare, yet their underreporting remains a challenge. Extracting spontaneous and non-automatic reports from free-text narratives contributes to this low rate of reporting. An automatic ADR detection system can mitigate these issues by identifying, summarizing, and reporting ADRs in a document. This study presents an adverse drug reaction detector (ADRD), a natural language processing (NLP) framework applied to the psychiatric treatment adverse reactions (PsyTAR) dataset. Aiming to automate ADR analysis, the framework explores the relationship between ADRs and patient satisfaction. Methods: A comprehensive eight-phase approach was employed in the ADRD framework, utilizing Python programming language libraries and NLP tools. The dataset underwent meticulous preprocessing, and the subsequent phases involved data summarization, pattern identification, data cleaning, sentiment calculation, assessment of drug effectiveness and usefulness, analysis of medical conditions, and identification of the most effective and ineffective drugs for each condition. Results: Analyzing 891 comments related to four unique drugs (i.e., Zoloft, Lexapro, Cymbalta, and Effexor XR) from patients with 285 distinct conditions, the framework offered insights into the dataset structure, statistical indicators, distribution of ratings and ADR counts, the impact of ratings on ADR counts, and length of comments’ influence on ratings. Conclusion: The challenges of extracting ADR reports from free-text narratives have led to their underreporting. ADRD offers an automated and insightful approach for enhancing ADR analysis and reporting processes, making strides toward bridging the gap in ADR reporting.

Citric acid cross-linking of a hydrogel from Aloe vera (Aloe barbadensis M.) engenders a pH-responsive, superporous, and smart material for drug delivery.

The current research work is based on the evaluation of a citric acid (CA) cross-linked Aloe vera (Aloe barbadensis M.) leaf hydrogel (CL-ALH) for pH-dependent and sustained drug release application. The CA was used in different concentrations (1.25, 2.5, 5.0, and 10.0%) to cross-link the ALH using homogenous reaction conditions. The synthesis of CL-ALH was confirmed through Fourier transform and nuclear magnetic resonance spectroscopic studies. The thermal analysis indicated that the ALH and CL-ALH were stable and decomposed in two steps. The scanning electron microscopic images of CL-ALH confirmed its porous nature due to the presence of interconnected channeling. The swelling of CL-ALH was evaluated at pH 1.2, 6.8, and 7.4 as well as in deionized water (DW). High swelling of CL-ALH was observed in DW, and at pH 7.4 and 6.8 whereas, less swelling of CL-ALH was witnessed at pH 1.2. CL-ALH also exhibited swelling/deswelling behavior in DW and ethanol, DW and normal saline, and at pH 7.4 and 1.2. Tablets were prepared from CL-ALH as a release retarding agent demonstrating the sustained release of venlafaxine hydrochloride (VFX) for 8 h. Whereas, VFX was released within 4 h from the ALH-based tablet formulation (un-cross-linked material) indicating the prolonged and sustained release behavior of CL-ALH. The VFX was released from CL-ALH tablets and followed zero-order kinetics. The mechanism followed by VFX release from CL-ALH tablets was non-Fickian diffusion. The in vivo fate of the tablet formulation was observed through an X-ray study. The CL-ALH-based tablet safely passed through the stomach of a stray dog without any significant erosion and then disintegrated in the small intestine and colon. These findings confirmed that the CL-ALH is an effective excipient for designing a sustained-release drug delivery system for the small intestine and colon.

In silico exploration of venlafaxine, a potential non-tricyclic antidepressant in a liposomal formulation for nose-to-brain drug delivery

Objective Non-tricyclic antidepressants (non-TCAs) work by preventing the intake of norepinephrine and serotonin. Therefore, the aim of this study was to identify a potent non-TCAs and to develop liposomal formulation, characterize and to determine the drug release study across model of dialysis membrane via in vitro and in silico techniques. Methods The in silico docking analysis identified venlafaxine (VLF) as the best non-TCAs with the depressant targets (PDB ID: 3PBL and 4BVN). VLF-loaded liposomal formulation was prepared by the thin-film hydration technique and characterized by physicochemical properties, including entrapment efficacy, in vitro drug release, particle size analysis, and FTIR. Moreover, this article also compares VLF and VLF-loaded with liposome carriers (LPs) based on nose-to-brain drug delivery approaches to treating depression. Results Drug release profiles of the optimal liposomal formulation of VLF-LPs were examined in the high entrapment efficiency 94.13 ± 1.20% was attained at 224 nm, composed of spherical particles having a mean particle size of 191 ± 2.0 nm, a polydispersity index of 0.281 ± 0.06 and zeta potential of −20.3 mV. The best formulation of VLF-LPs was more effective than oral VLF treatment, as shown by the in vitro drug release data. Conclusion The results show that the VLF-LPs formulation is a promising potential platform for application in nose-to-brain drug delivery. Thus, highlighting the robustness of the intranasal drug delivery system with enhanced pharmaceutical properties, efficacy, and bioavailability for the anti-depression effect.

Effect of rGO content on enhanced Photo-Fenton degradation of Venlafaxine using rGO encapsulated magnetic hexagonal FeTiO3 nanosheets

In this work, we synthesized magnetic reduced graphene oxide (rGO) encapsulated hexagonal FeTiO3 (FTO@rGO) nanosheets with rGO loading amount of 0, 1, 5 and 10 wt%, with a primary objective of efficiently degrading venlafaxine (VLF) through photo-Fenton processes across a wide pH range of 3–11. The inherent visible-light photocatalytic ability of ilmenite FeTiO3 (FTO) and catalytic activation of H2O2 by Fe sites during the photo-Fenton process were established. Through the strategic integration of rGO, all FTO@rGO catalysts show higher VLF degradation rate than FTO in photo-Fenton evolution experiments and the FTO@rGO catalysts with rGO loading amount of 5 wt% presents the highest VLF degradation rate (100 % VLF degradation at 90 min), which attributed to the accelerated migration of photo-generated electrons and the efficient Fe2+/Fe3+ cycle. Furthermore, the encapsulation of rGO significantly mitigated Fe leaching throughout the reaction pH range, directing H2O2 activation to occur at the FTO@rGO interface instead of in solution. Through a comprehensive analysis, we identified 47 intermediate products of VLF and deduced the degradation pathway based on 12 representative intermediates. The degradation process was primarily driven by hydroxyl radicals as the dominant reactive oxygen species, complemented by the contribution of superoxide radicals, photogenerated electrons, and holes during the FTO@rGO-catalyzed photo-Fenton process. This study not only expands the application of ilmenite in the realm of advanced oxidation processes (AOPs) but also provides valuable insights for the future exploration and development of metal oxide/carbonaceous heterostructure catalysts.

ZIF-67/Ag3VO4 based S-scheme heterojunction for visible light driven rapid photocatalytic removal of venlafaxine

A binary S-scheme heterojunction photocatalyst, ZIF-67/Ag3VO4 (ZAV), was successfully synthesized using a hydrothermal technique. The optimal ZAV-30 (ZIF-67/30 wt%Ag3VO4) demonstrated excellent performance by degrading 98.5% of Venlafaxine (VEN) within 60 min under visible light. Extensive investigations were carried out regarding the crystal structure, morphology, composition, specific surface area, optical characteristics and electrochemical impedance. The ZAV-30 heterojunction photocatalyst outperformed bare ZIF-67 and Ag3VO4 photocatalysts, primarily due to enhanced photon absorption and improved charge carriers’ separation via S-scheme transfer, redox capability and high charge transfer capacity supported by electrochemical experiments and photoluminescence. The S-scheme transfer was validated by in-situ XPS measurements after light exposure. Scavenger experiments indicated that both •OH and •O2− played crucial roles as active species in the photocatalytic process. Mass spectrometry (MS) analysis of intermediates facilitated the proposal of a probable photocatalytic degradation pathway for VEN. The photoactivity of the heterojunction was influenced by a range of factors including the pH of the VEN solution, initial VEN concentration, ZAV photocatalyst dosage, and ion effects. Interestingly the ZAV-30 heterojunction exhibited superior performance in lake water, tap water and river water too. Importantly, the ZAV-30 heterojunction exhibited excellent stability and reusability, making it a promising photocatalyst.

Enhanced removal of emerging pollutants through visible light-activated carbon nitride materials immobilized over 3D printed structures

This study investigates the performance of carbon nitride (CN) photocatalysts immobilized on 3D printed cylindrical supports for the removal of selected emerging pollutants, namely venlafaxine (VFX), citalopram (CTP), fluoxetine (FXT), and carbamazepine (CBZ), due to their rising consumption as antidepressants and the significant concerns for public health and the environment, mainly due to the direct impact of their presence in surface waters. The CN photocatalysts were synthesized using two precursors (dicyandiamide and urea), forming four different CN materials. Among the immobilized CN photocatalysts tested, the bulk CN prepared from urea (CNB-U/PLA) revealed the highest efficiency for the removal of VFX as the target antidepressant (above 90% after 30 min), which was ascribed to the lower recombination of photogenerated charges of this photocatalyst. The reuse tests confirmed the robust and effective photocatalytic performance of the CNB-U/PLA photocatalyst over multiple cycles, while its versatility with different support configurations demonstrates its adaptability and broad potential for various photocatalytic applications. The simultaneous removal of the four antidepressants was performed at low concentrations (1.8 μM), employing the most efficient immobilized photocatalyst (CNB-U/PLA), yielding remarkably high conversion rates (above 90% for VFX, CTP, and FXT, and around 70% for CBZ, after 60 min) under visible irradiation. The results demonstrate the ability of the immobilized CN system to effectively eliminate contaminants with different chemical properties. This study emphasizes the potential of this approach for comprehensive emerging pollutants removal, highlighting its significance in water treatment and environmental remediation strategies.

A comprehensive insight into the transformation pathways and products of fluoxetine and venlafaxine in wastewater based on molecular networking nontarget screening

Fluoxetine (FLX) and venlafaxine (VEN) are widely used antidepressant pharmaceuticals and were frequently detected in wastewater. Despite incomplete mineralization during biological wastewater treatment processes has been revealed, little is known about their transformation products (TPs) formed in the biological systems. To fill this gap, batch reactors and molecular networking nontarget screening were employed to identify the TPs and explore the transformation pathways of FLX and VEN in wastewater. On the basis, the concentrations of the TPs in wastewater treatment plants (WWTPs) were determined and their toxicity was predicted. The removal rate constants per unit of biomass of FLX and VEN were up to 0.3192 and 0.1644 L/(gMLSS*d) in batch experiments, respectively. Subsequently, 11 TPs of VEN and 11 TPs of FLX were tentatively identified, among which 9 TPs of FLX and 5 TPs of VEN were newly reported in this study. The proposed transformation pathways provided new insights into the transformation reactions including dehydrogenation, N-formylation and hydroxylation for FLX, and formylation, epoxidation and methylation for VEN. Particularly, N-succinylation and demethylation were the dominant transformation pathways for FLX and VEN during transformation processes. The results of sampling campaigns revealed that the accumulated concentration of TPs were higher than the concentrations of VEN in effluent of WWTPs. In silico prediction results suggested that certain TPs have higher toxicity, persistence and biodegradability than their corresponding parent compounds of FLX and VEN. In addition, VEN-TP264(a) showed higher ecological risks than VEN. This study revealed the transformation processes and fate of FLX and VEN in wastewater, indicating that greater concerns should be exerted on the toxicity detection and control of the TPs of FLX and VEN in the treated wastewater.