Initial Drug Concentration Research Articles

Iron metal-organic framework nanofiber membrane for the integration of electro-Fenton and effective continuous treatment of pharmaceuticals in water

In this study, an iron metal-organic framework (Fe-MOF) was synthesized and immobilized by electrospinning technique with the objective of obtaining a membrane composed of nanofibers of this material (Fe-MOF nanofiber membrane). The characterization performed by XRD, TEM, SEM, EDS mapping and FTIR confirmed the correct synthesis of Fe-MOF as well as its correct retention in the elaborated membranes. The usefulness and effectiveness of the Fe-MOF nanofiber membrane as a catalyst for the electro-Fenton process was evaluated by performing sulfamethoxazole degradation tests. Different parameters such as the effect of intensity (25 and 100 mA), the effect of the drug initial concentration (10–50 mg/L) and the reusability of membranes were studied. Then, the degradation of a drug mixture formed by sulfamethoxazole and antipyrine was evaluated, reaching a degradation of 92.10 % and 87.43 % respectively for each drug in 4 h at 25 mA. In addition, the identification of reactive oxygen species was ascertained by scavenger assays. The study of degradation products was also carried out and their toxicity was predicted by ECOSAR program, concluding that the environmental toxicity would disappear with mineralization. Finally, given the good results obtained in batch tests, the behavior of the process was studied in a system that works continuously, achieving a stable degradation of 83.10 % in the case of treatment with a mixture of drugs. This confirmed the stability of the Fe-MOF nanofiber membrane, as well as, its catalytic activity, making it suitable for long-term treatments.

5-Fluorouracil adsorption on graphene oxide-amine modified graphene oxide/hydroxyapatite composite for drug delivery applications: Optimization and release kinetics studies

The present study focused on investigation of graphene oxide/hydroxyapatite (GO/HAp) and amine modified graphene oxide/hydroxyapatite (GO-NH2/HAp) composites as potential drug carrier agents for 5-Fluorouracil (5-FU). Incorporation of 5-Fluorouracil drug was performed via adsorption through π-π interactions and electrostatic attractions. Modification of graphene oxide was performed for the production of amine modified graphene oxide/hydroxyapatite composite with the intention of enhancing adsorption performance. The X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and zeta potential/particle size analysis were performed for particle characterization while Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analysis were used to analyze detailed morphological properties. Experimental design studies were followed out in order to determine the effect of adsorption parameters including graphene oxide amount, pH and initial drug concentration on 5-Fluorouracil adsorption behavior. Adsorption isotherms of both composites with unmodified and modified GO were best fitted to Freundlich model with R2 values of 0.9616 and 0.9682 respectively. The maximum adsorption capacities (qm) were calculated as 47.3 mg/g and 18.4 for graphene oxide/hydroxyapatite and amine modified graphene oxide/hydroxyapatite composites respectively at pH 2.0. The highest adsorption percentage was obtained for amine modified graphene oxide/hydroxyapatite composite as 40.87 % at pH 2.0 condition. In vitro release kinetic studies revealed that compliance with Higuchi and Korsmeyer-Peppas kinetic models were observed for graphene oxide/hydroxyapatite, whereas zero order and Korsmeyer-Peppas kinetic models pointed out as the well-fitted model for amine modified graphene oxide/hydroxyapatite composite. The release period of 5-FU drug from all composites were continued up to 8–10 h in physiological conditions (pH 7.4, 37 °C) indicating an achieved controlled release. Based on the overall findings, graphene oxide/hydroxyapatite and amine modified graphene oxide/hydroxyapatite composites could be suggested as a potential drug delivery agent for 5-FU in clinical applications.

Eco-friendly tea waste magnetite nanoparticles for enhanced adsorptive removal of norfloxacin and paroxetine from water

Traces of pharmaceuticals have been detected in water cycle raising concerns regarding the potential risks to human health and aquatic environment. Accordingly, removal of such compounds from water samples is a major concern. Herein, a facile and green NaOH modified tea waste magnetite nanoparticles have been fabricated for the adsorptive removal of a commonly used antibiotic (norfloxacin) and antidepressant (paroxetine) from water samples. The synthesized nanoparticles were characterized using TEM, FT-IR, DLS and VSM. Factors affecting the adsorption efficiency have been investigated with respect to pH (5, 7 and 9), adsorbent amount (0.125, 0.25 and 0.5 g), initial drug concentration (25, 50 and 100 µg/mL) and contact time (0.5, 1 and 2 h). The adsorption isotherms have been calculated. A percentage removal of 98 % and 99 % were obtained for simultaneous removal of 50 µg/mL norfloxacin and paroxetine, respectively in 2 h. Monitoring norfloxacin and paroxetine concentrations was performed through a validated HPLC-DAD method. The reusability of the nanoparticles has been studied for 3 adsorption–desorption cycles. No significant loss in adsorption efficiency was observed offering a sustainable water treatment. This study would offer a facile, green and economic protocol for the removal of complex organic compounds from water resources.

Effect of doping on the morphology of cerium molybdate: A mechanistic approach towards efficient energy storage and sustainable environmental mitigation through heterogeneous photocatalysis

In this paper, we describe the synthesis of cerium molybdate (Ce2(MoO4)3) and different compositions of Bi-doped cerium molybdate (Ce2-xBix(MoO4)3) where x = 0.01, 0.03, 0.05, 0.07, and 0.09, through simple co-precipitation method. The synthesized materials were optically, structurally, and morphologically characterized by various sophisticated techniques, including UV–visible, FTIR, Raman, PXRD, BET, and SEM-EDX. Upon addition of bismuth, the optical band gaps are reduced from 3.35 eV (Ce2(MoO4)3) to 2.83 eV Ce1.93Bi0.07(MoO4)3. The charge storage potential and AC conductivity of the synthesized materials were investigated through dielectric studies where the dielectric constant increased by increasing dopant concentration up to 7 %. At 20 Hz, Ce1.93Bi0.07(MoO4)3 showed a significantly greater dielectric constant (3.597 × 106) compared to undoped Ce2(MoO4)3 (3.262 × 105). Similarly, the AC conductivity of Ce1.93Bi0.07(MoO4)3 increased up to 4.758 S m−1 compared to the undoped Ce2(MoO4)3 (2.270 S m−1) at 20 MHz. The photocatalytic efficiency was investigated against diclofenac potassium, which also considerably improved by increasing bismuth content. The maximum photodegradation efficiency of 87.9 % was observed for Ce1.93Bi0.07(MoO4)3 in 180 min under UV light irradiation at optimized conditions (pH = 4, catalyst dosage = 20 mg, and initial concentration of drug = 5 mg L−1). The photocatalytic reaction followed pseudo-first-order kinetics with a rate constant of 0.0108 min−1 with stability up to five successive runs of photocatalytic activity indicating its good recyclability. These findings suggest that Bi-doped cerium molybdate could be used as a promising material for photocatalysis and energy storage devices.

Studies on Sorption and Release of Doxycycline Hydrochloride from Zwitterionic Microparticles with Carboxybetaine Moieties.

The aim of this study was to examine the use of zwitterionic microparticles as new and efficient macromolecular supports for the sorption of an antibiotic (doxycycline hydrochloride, DCH) from aqueous solution. The effect of relevant process parameters of sorption, like dosage of microparticles, pH value, contact time, the initial concentration of drug and temperature, was evaluated to obtain the optimal experimental conditions. The sorption kinetics were investigated using Lagergren, Ho, Elovich and Weber-Morris models, respectively. The sorption efficiency was characterized by applying the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The calculated thermodynamic parameters (ΔH, ΔS and ΔG) show that the sorption of doxycycline hydrochloride onto zwitterionic microparticles is endothermic, spontaneous and favorable at higher temperatures. The maximum identified sorption capacity value is 157.860 mg/g at 308 K. The Higuchi, Korsmeyer-Peppas, Baker-Lonsdale and Kopcha models are used to describe the release studies. In vitro release studies show that the release mechanism of doxycycline hydrochloride from zwitterionic microparticles is predominantly anomalous or non-Fickian diffusion. This study could provide the opportunity to expand the use of these new zwitterionic structures in medicine and water purification.

Solar light driven degradation of piroxicam and paracetamol by heterogeneous photocatalytic fenton system: Process optimization, mechanistic studies and toxicity assessment

The widespread occurence of pharmaceutical pollutants seriously threatens the environment and human well-being. In the present study, zinc ferrite nanoparticles (ZnFe2O4 NPs) have been synthesized by co-precipitation method and used as photocatalyst for the degradation of two most commonly prescribed painkillers, piroxicam (PXM) and paracetamol (PCM), via heterogeneous Fenton process under the solar light. The synthesized ZnFe2O4 NPs showed a narrower band gap i.e. 1.87 eV, signifying the ability to efficiently work in visible light range. In context of photocatalytic applications, the operational conditions were optimized to achieve maximum degradation. PCM and PXM were completely degraded (100%) at the optimized photocatalytic dose (20 mg L−1), reaction time (180 min), initial drug concentration (10 mg L−1), and pH (6.0), which is close to the natural environment. The extent of mineralization as estimated by the reduction of total organic carbon (TOC) was observed to be ∼91 and 82% for PCM and PXM respectively. Kinetic studies revealed that photocatalytic degradation followed pseudo-first-order kinetics. Moreover, the ZnFe2O4 NPs retained ∼90 % of photocatalytic activity after five consecutive reaction cycles, showing remarkable reusability and stability of catalyst.

Continuous flow column adsorption and desorption for the study of interaction of fluoroquinolone antibiotic ofloxacin hydrochloride with ZnO and CuO nanometal oxides in aqueous solution: (Continuous column adsorption desorption)

Broad-spectrum antibiotic, major veterinary medicines, due to large consumption and inappropriate disposal contribute a major part in generation of pharmaceutical pollutants in aquatic environment. The study investigates the interaction of nanometal oxides for adsorption and desorption of Fluoroquinolone antibiotic, ofloxacin hydrochloride from aqueous solution using vertical and sequential bed adsorption columns: designing parameters of adsorption column determined using bed depth service time model. To optimize the continuous flow column adsorption, varying initial drug concentration and flow rates have been studied using ZnO and CuO nanoparticles at pH 4, already determined for optimized batch studies. To access the characteristic behaviour of breakthrough curves, Thomas model and Yoon-Nelson models have been studied, which were in good agreement with experimental data. Sequential bed column shows slightly better results than vertical bed column as the sequential bed is simple and economical, the solution flows in continuous manner under gravity without any mechanical devices and come into contact with fresh adsorbent bed having same amount as that in vertical bed. Therefore sequential bed column can consider in small scale industries for pharmaceutical wastewater treatment. Column desorption experiments have also been carried out by using HCl/NaOH as desorbing agent for the regeneration of drug loaded adsorbent column.

High performance adsorptive removal of emerging contaminant paracetamol using a sustainable biobased mesoporous activated carbon prepared from palm leaves waste

In this work, a novel bio-based carbon material was prepared via a facile pyrolysis method using chemically activated dead palm leaves as a sustainable and efficient carbon precursor. The as-prepared activated carbon with KOH activation (AC-KOH) was characterized by XRD, FTIR, SEM, EDS, and BET analysis. The AC-KOH was used for the adsorption of paracetamol (PCT) from aqueous solutions and the effect of experimental conditions such as contact time (0.08–30 hours), pH (2.96–12.1), initial drug concentration (1–50 mg L−1), adsorbent dosage (0.12–1.2 g L−1), and temperature (25–45 °C) was investigated. The system achieved equilibrium in 4 hours and PCT uptake was highly dependent on solution pH. A maximum removal efficiency was achieved at a pH of around 5.86. Kinetic model analysis indicated that the uptake follows the pseudo-second-order model (R2 = 0.989). The maximum monolayer capacity of the developed AC for PCT was found to be 87.87 mg g−1 at time of equilibrium (4 hours), solution pH of 5.86, adsorbent dose of 0.2 g L−1, concentration of 1–50 mg L−1 and temperature of 25 °C. The PCT uptake process was feasible, spontaneous (ΔG0 < 0), and endothermic (ΔH0 > 0) according to the thermodynamics evaluation. The mechanism of PCT adsorption primarily involved pore-filling, π-π interaction, and H-bonding. The adsorbent exhibited reasonable reusability towards PCT adsorption up to two regeneration cycles. The results of this work support that the dead palm leaves are efficient, cheap, and sustainable feedstock for producing activated carbon adsorbent to be used for an efficient removal of PCT from real wastewater samples.

Carbamazepine adsorption with a series of organoclays: removal and toxicity analyses

Organoclays have been used as efficient adsorbents for pharmaceutical pollutants present in waters. Carbamazepine (CBZ) is one of the drugs most frequently found in water bodies. In this study, four organoclays were prepared by modifying bentonite with the cationic surfactants hexadecyltrimethylammonium bromide (HDTMA) and octadecyltrimethylammonium bromide. The synthesized materials were characterized by XRD, CHN, FTIR, TG, BET and SEM analyses, confirming organophilization. The surfactants were interspersed in different arrangements in the interlayer space. CBZ sorption was investigated through batch equilibrium experiments, under variation of the pH, contact time, dosage of adsorbent, and initial drug concentration. Changes in pH showed no adsorption influence. CBZ sorption by the organoclays followed a pseudo-second-order kinetics. The best sorption performance was obtained for the BCN1-HDTMA100 clay, with a capacity of 34.34 ± 1.41 mg g−1, about ten times greater than the unmodified bentonite under the same conditions. This may be attributed to the higher surfactant content. The adsorption isotherm at 25 ºC showed linear behavior. Toxicity tests of the organoclays and corresponding medium in presence of CBZ were carried out. This is a novelty report. Most of the organoclays had no toxicity against Artemia salina. The toxicity of the medium after adsorptive treatment was eliminated. Organoclay-CBZ hybrids were also characterized after adsorption. FTIR and TG analyzes confirmed the incorporation of the drug. Hydrophobic interaction was the dominant contribution evaluated to the adsorption of CBZ. The results demonstrated that organoclays can be a promising alternative adsorbent for the removal of pharmaceutical pollutants in water remediation.

Definition of Design Space for Preparation and Stability of Tramadol Hydrochloride Loaded Nanoparticles Using OFAT Experiments for Infusion in Pain Management

This paper presents an experimental study on preparation of tramadol hydrochloride (TrH) loaded nanoparticles, and stability determination in various infusion solutions. In this study, various nanoparticle preparation parameters based on w/o/w emulsification solvent evaporation method, including stabilizer type, stabilizer concentration, polymer concentration, homogenization speed and initial drug amount were systematically tested to verify their versatility for preparing nanoparticles. Initially both particle size and encapsulation efficiency of nanoparticles were changed significantly with the change in surfactant and polymer ratio (p<0.05). However, homogenization speed only changed particle size (average size 339.3±1.8 nm for 15000 rpm, 318.9±6.4 nm for 20000 rpm and 237.2±7.8 nm for 25000 rpm) (p<0.05) and initial drug concentration is only affected the encapsulation efficiency (34.2±0.7% for 4 mg/mL and 33.2±0.9 for 1.6 mg/mL) (p<0.05). Storage at room temperature for 3 months resulted in an increase in particle size and polydispersity index. Prepared nanoparticles showed the best stability after storage at – 20 °C for in 3 months. Finally, storage of nanoparticles in various infusion solutions resulted an undesirable changes for 6% Hydroxyethyl starch in 0.9% sodium chloride injection, 10% Dextran 40 and 4% Succinyl gelatin solutions. It was shown that an appropriate delivery of TrH loaded PLGA nanoparticles as infusion can be prepared only in water for injection, 20% Mannitol, 0.9% Sodium chloride and 5% Dextrose solutions.

Validity conditions of approximations for a target-mediated drug disposition model: A novel first-order approximation and its comparison to other approximations.

Target-mediated drug disposition (TMDD) is a phenomenon characterized by a drug's high-affinity binding to a target molecule, which significantly influences its pharmacokinetic profile within an organism. The comprehensive TMDD model delineates this interaction, yet it may become overly complex and computationally demanding in the absence of specific concentration data for the target or its complexes. Consequently, simplified TMDD models employing quasi-steady state approximations (QSSAs) have been introduced; however, the precise conditions under which these models yield accurate results require further elucidation. Here, we establish the validity of three simplified TMDD models: the Michaelis-Menten model reduced with the standard QSSA (mTMDD), the QSS model reduced with the total QSSA (qTMDD), and a first-order approximation of the total QSSA (pTMDD). Specifically, we find that mTMDD is applicable only when initial drug concentrations substantially exceed total target concentrations, while qTMDD can be used for all drug concentrations. Notably, pTMDD offers a simpler and faster alternative to qTMDD, with broader applicability than mTMDD. These findings are confirmed with antibody-drug conjugate real-world data. Our findings provide a framework for selecting appropriate simplified TMDD models while ensuring accuracy, potentially enhancing drug development and facilitating safer, more personalized treatments.

Treatment of wastewater containing ciprofloxacin using the hybrid treatment approach based on acoustic cavitation

AbstractThe present work investigates the treatment of wastewater containing an antibiotic, ciprofloxacin (CIP), using acoustic cavitation (AC) coupled with other advanced oxidation processes (AOPs). For the laboratory scale degradation study, operating parameters like drug concentration, operating pH, and initial temperature were initially optimized and then used in hybrid approach of AC in combination with AOPs. At 15 m/L initial drug concentration, neutral pH of 7, and ambient temperature of 30°C, optimum CIP degradation of 13.66% was obtained within 120 min of operation. The intensification of the AC‐based approach was subsequently achieved using other oxidants like H2O2, potassium persulphate (KPS), and O3. The combination of AC with H2O2 and KPS resulted in 44.30% and 35.41% CIP degradation, respectively, while AC combined with ozone resulted in almost complete degradation of CIP within 90 min of treatment with a maximum cavitational yield of 4.761 × 10−6 mg/J. The cost estimation for the optimized treatment approaches revealed that AC combined with ozone is the best process for degradation with the least operational cost of 8.7 Rs/L (105 US $/m3). Complete degradation of CIP with AC + O3 based approach at much lower costs opens a window for implementation in the pharmaceutical industries.

Ultraviolet Photodegradation of Ciprofloxacin Using Zinc Oxide and Iron-Doped Zinc Oxide (Fe-ZnO) Nanoparticles (NPs): Kinetic and Isotherm Measurements

This article describes the auto-combustion sol-gel synthesis of zinc oxide (ZnO), 0.1% iron-doped zinc oxide (0.1% Fe-ZnO), and 0.2% iron-doped zinc xide (0.2% Fe-ZnO) NPs with the goal of determining their suitability as a photocatalyst for the degradation of a hazardous antibiotic drug (ciprofloxacin). The functional group, surface morphology, and crystallinity of ZnO, 0.1% Fe-ZnO, and 0.2% Fe-ZnO NPs were studied using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and x-ray diffraction analysis (XRD). Various parameters, such as solution pH, catalyst dosage, light exposure period, and initial drug concentration, were optimized for quantitative degradation. The photocatalytic degradation of ciprofloxacin using ZnO, 0.1% Fe-ZnO, and 0.2% Fe-ZnO follows pseudo-first-order kinetics. The proposed method has been applied to commercial formulations such as Ciprofloxacinro, Ciprofloxacinro XR, and Ciprofloxacinro ProQuin XR with satisfactory results.

Construction of novel CoFe2O4/h-BN/MIL-53 (Al) magnetic nanocomposites for the removal of hazardous antibiotics from water

In this study, the CoFe2O4/hexagonal boron nitride (h-BN) nanocomposite prepared via the microwave irradiation method, was hybridized with the MIL-53 (Al) metal–organic framework. The structure and morphology of the magnetic CoFe2O4/h-BN/MIL-53(Al) nanocomposite were investigated using Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analyzer (EDX), Brunauer-Emmett-Teller (BET) surface area analysis, vibrating sample magnetometry (VSM) and zeta potential analysis. The adsorption performance of the CoFe2O4/h-BN/MIL-53 (Al) nanocomposite as a magnetically recyclable adsorbent for removing tetracycline (TC) and ciprofloxacin (CIP) antibiotics in aqueous solutions was investigated under different influence factors, including contact time, initial drug concentration, adsorbent dosage, pH conditions, temperature and ionic strength. The results indicated that the nanocomposite adsorbed 100 % of drugs within a short time (20–––30 min), with a maximum adsorption capacity of 625.00 mg g-1and 270.27 mg g−1, respectively. Additionally, the adsorption mechanism was also discussed based on the obtained results. After the drug absorption and removal process, the nanocomposite can be easily separated and reused several times without losing its absorption activity, therefore making it an appropriate choice for removing drugs from polluted water.

Synthesis and characterization of new composite from modified silica-coated MnFe2O4 nanoparticles for removal of tetracycline from aqueous solution.

In this study, a new composite from silica coated MnFe2O4 nanoparticles, diethylenetriamine, 3-chloropropyl trimethoxysilane and Mg-Al Layered Double Hydroxide (Mg-Al LDH/DETA/CPTMS/SCNPs) composite was synthesized. The Mg-Al LDH/DETA/CPTMS/SCNPs composite was examined by Fourier transform infrared spectrometer (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDS), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA) and Vibrating Sample Magnetometry (VSM). The synthesized composite exhibited magnetic property with a saturation magnetization of 0.40 emu g-1. The Mg-Al LDH/DETA/CPTMS/SCNPs composite was utilized as a successful adsorbent for removal of tetracycline from aqueous solutions. The effect of various operation factors such as initial drug concentration, adsorbent dosage, pH and contact time were investigated. The optimized variable conditions such as adsorbent dose of 60 mg L-1, drug concentration of 100 mg L-1, pH = 7 and contact time 30 min were obtained. For describing the adsorption isotherms, the Langmuir, Freundlich and Temkin adsorption models were utilized. The results indicated that the adsorption isotherm is in good agreement with Langmuir model. According to the Langmuir analysis, the maximum adsorption capacity (qm) of the Mg-Al LDH/DETA/CPTMS/SCNPs composite for tetracycline was obtained to be 40.16 mg g-1. The kinetic studies revealed that the adsorption in all cases to be a pseudo second-order process. The negative value of ΔG° and the positive value of ΔH° showed the adsorption process to be spontaneous and endothermic.

Removal of Amoxicillin Drug from Aqueous Solution by using Marble Powder Surface Activated by Several Acids

In recent years, the problem of the removal drug from wastewater has become one of the most important global problems due to the accumulation of large quantities of drugs on the surface of the water, which causes a lack of penetration of sunlight into water contaminated with drug, and this leads to a reduction in aquatic life forms for all living organisms and also leads to problems large environmental impacts and many dangerous diseases for humans. An attempt was made to prepare an environmentally friendly, economical and available surface that has a high absorption capacity to remove the contaminants of pharmaceuticals such as amoxicillin (AMX) drug. In this study, waste material such as white marble was used as an absorbent material, and its adsorption properties were enhanced and activated by treating it with several acids (HCL, H2SO4, and HNO3). The prepared white marble before and after adsorption were characterized by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The influence of several parameters like contact time (5–120 minutes), initial concentration of drug (10–50 mg/L), adsorbent dosage (0.02–0.2 g), solution temperature (10–40oC), and pH (2–10) was estimated for adsorption method optimization. The equilibrium adsorption result was examined utilizing the isotherm Langmuir, and isotherm Freundlich models. The attained data indicated that, sorption was found to be fast, 84.44% within 1 hour.

Nano spinel NiAl2O4: structure, optical and photocatalytic performance evaluation and optimization

Four kinds of spinel NiAl2O4 were synthesized by the polyacrylamide gel method using Al2(SO4)3·18H2O and Al(NO3)3·9H2O as aluminum salts and anhydrous NiSO4 and NiSO4·6H2O as nickel salts. The effects of different aluminum salts and nickel salts on the structure, optical and photocatalytic activity of spinel NiAl2O4 were confirmed by various characterizations. There is no NiO impurity in the spinel NiAl2O4 synthesized with Al2(SO4)3·18H2O as aluminum salt, while NiAl2O4, NiO and C–O functional group coexist in the target product with Al(NO3)3·9H2O as aluminum salt, and C–O functional group and NiO inhibits the photocatalytic activity of the system. Based on photocatalytic experiment, response surface methodology and free radical verification experiment, the influence of experimental parameters including synthesis pathway, initial drug concentration, initial pH and catalyst content on the photocatalytic activity of spinel NiAl2O4 and the main active species involved in the reaction were investigated. The degradation percentage of spinel NiAl2O4 synthesized with Al2(SO4)3·18H2O as aluminum salt and NiSO4·6H2O as nickel salt was 86.3% at the initial concentration of 50 mg l−1, pH = 5.33 and catalyst content of 1 g l−1. The mechanism investigation confirmed that the C–O functional group plays the dual role of impurity level and electron transfer in the degradation of tetracycline hydrochloride by spinel NiAl2O4.

Zero-order Release of Metformin in Polyacrylamide Hydrogel

Water-soluble polymers with a three-dimensional crosslinked network structure, known as a hydrogel, has widespread applications in clinical and experimental medicine as drug carriers. Upon entering the targeted area for treatment, hydrogel loaded with drugs releases them through both diffusion and self-degradation mechanisms. In this study, the drug release process in polyacrylamide hydrogel uniformly loaded with metformin hydrochloride is investigated. To achieve a uniform drug release rate from the hydrogel, we establish a statistical model of drug release from polyacrylamide hydrogel using response surface methodology based on experimental design technique. The established statistical model can predict drug release behavior at a low cost within the design domain. The relationship between initial drug concentration and drug release rate in metformin-loaded polyacrylamide hydrogel has been investigated. A zero-order drug release effect in hydrogels is achieved through an optimized design of the initial distribution of drug concentration of a five-layered drug-containing hydrogel. This study has significant implications for the realization of drug molecule transport and sustained release in vivo.

Folic acid conjugated poly (Amidoamine) dendrimer grafted magnetic chitosan as a smart drug delivery platform for doxorubicin: In-vitro drug release and cytotoxicity studies

This study reports the development of a magnetic and pH-responsive nanocarrier for targeted delivery and controlled release of doxorubicin (DOX). A multifunctional magnetic chitosan nanocomposite (FA–PAMAMG2–MCS) was fabricated by grafting poly(amidoamine) dendrimer and folic acid onto the MCS surface for active targeting. DOX was loaded into this core-shell bio-nanocomposite via adsorption. Structural and morphological characterization of the prepared nanomaterials was performed using XRD, FT-IR, VSM, TGA, BET, FE-SEM/EDX, and TEM techniques. Adsorption capacity of the FA–PAMAMG2–MCS was optimized by changing diverse parameters, such as pH, initial drug concentration, temperature, contact time, and adsorbent dosage. The maximum adsorption capacity for DOX was 102.85 mg g−1 at 298 K. The in-vitro drug release curve at pHs 5.6 and 7.4 manifested a faster drug release from the prepared nanocarrier in acidic environments and, conversely, a slower release in neutral environments over 48 h. The release kinetics followed Peppas-Sahlin models, showing non-Fickian behavior. Moreover, the in-vitro cytotoxicity studies against the human breast cancer (MDA-MB 231) cell line demonstrated the remarkable anticancer activity of the DOX@FA–PAMAMG2–MCS and declared its potency for nanomedicine applications. This multifunctional system could overcome limitations of conventional chemotherapeutic agents through pH-triggered drug release, enabling targeted cytotoxicity against cancer cells.

Lipid-Based Nanocarriers for Delivery of Neuroprotective Kynurenic Acid: Preparation, Characterization, and BBB Transport.

Encapsulation possibilities of an extensively investigated neuroprotective drug (kynurenic acid, KYNA) are studied via lipid-based nanocarriers to increase the blood-brain barrier (BBB) specific permeability. The outcomes of various preparation conditions such as stirring and sonication time, concentration of the lipid carriers and the drug, and the drug-to-lipid ratio are examined. Considering the experimentally determined encapsulation efficiency, hydrodynamic diameter, and ζ-potential values, the initial lipid and drug concentration as well as the stirring and sonication time of the preparation were optimized. The average hydrodynamic diameter of the prepared asolectin-(LIP) and water-soluble lipopolymer (WSLP)-based liposomes was found to be ca. 25 and 60 nm under physiological conditions. The physicochemical characterization of the colloidal carriers proves that the preparation of the drug-loaded liposomes was a successful process, and secondary interactions were indicated between the drug molecule and the polymer residues around the WSLP membrane. Dissolution profiles of the active molecule under physiological conditions were registered, and the release of the unformulated and encapsulated drug is very similar. In addition to this outcome, the in vitro polar brain lipid extract (porcine)-based permeability test proved the achievement of two- or fourfold higher BBB specific penetration and lipid membrane retention for KYNA in the liposomal carriers relative to the unformatted drug.