Fourier Transform Infrared Studies Research Articles

DSC and FTIR study on the interaction between pentacyclic triterpenoid lupeol and DPPC membrane.

Natural products are a great resource for physiologically active substances. It is widely recognized that a major percentage of current medications are derived from natural compounds or their synthetic analogues. Triterpenoids are widespread in nature and can prevent cancer formation and progression. Despite considerable interest in these triterpenoids, their interactions with lipid bilayers still need to be thoroughly investigated. The aim of this study is to examine the interactions of lupeol, a pentacyclic triterpenoid, with model membranes composed of 1,2‑dipalmitoyl‑sn‑glycerol‑3‑phosphocholine (DPPC) by using non-invasive techniques such as differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The DSC study demonstrated that the incorporation of lupeol into DPPC membranes shifts the Lβ'-to-Pβ' and Pβ'-to-Lα phase transitions toward lower values, and a loss of main phase transition cooperativity is observed. The FTIR spectra indicated that the increasing concentration (10mol%) of lupeol causes an increase in the molecular packing and membrane fluidity. In addition, it is found that lupeol's OH group preferentially interacts with the head group region of the DPPC lipid bilayer. These findings provide detailed information on the effect of lupeol on the DPPC head group and the conformation and dynamics of the hydrophobic chains. In conclusion, the effect of lupeol on the structural features of the DPPC membrane, specifically phase transition and lipid packing, has implications for understanding its biological function and its applications in biotechnology and medicine.

Self-associates of 1,2,4-triazole: FTIR studies, quantum chemical calculations and topological analysis

The Fourier Transform Infrared (FTIR) spectroscopic technique has been employed to study the self-associates of 1,2,4-triazole (Htrz) in solid phase. The self-associates have been identified using density functional theory (DFT) calculations carried out on various multimers of Htrz under B3LYP/6–311++ G(d, p) level. Comparison of the experimental and theoretical frequencies of N−H andC−Hstretching absorptional bands indicate that Htrz exists as multimers upto hexamer. The Occupancy of the anti-bonding orbitals of the proton donors, Natural bond Orbital (NBO), Frontier Molecular Orbital (FMO), Electrostatic potential surface (ESP), reduced density gradient (RDG) analyses have also been executed. In addition, topological parameters have also been analysed to characterize the hydrogen bonds and proton donating covalent bonds. The analyses show that pentamer is the most stable among all the H-bonded associates and the dimer 3 in which classical and non-classical H-bond interaction coexists is the least stable. The topological parameter values suggest that the N−H bonds of dimer1/pentamer are with the highest/smallest covalent character. The criteria proposed in literature to describe the covalent nature of bonds, in particular proton donor bonds, appears to fails in the Htrz dimer in which classical and non-classical hydrogen bonds coexist.

An investigation on the photocatalytic and antibacterial response of green fluorescent carbon dots synthesized from corn flour

Abstract The present work elucidates on a facile hydrothermal synthesis method for producing highly fluorescent carbon dots using corn flour as a natural carbon source. The structural confirmation was validated through XRD (X-ray Diffraction), HR-TEM (High-Resolution Transmission Electron Microscope), and FTIR (Fourier Transform Infra-Red) studies. The synthesized carbon dots exhibited an excitation-dependent photoluminescence (PL) emission. The optical band gap of as-synthesized carbon dots was estimated using UV-absorption spectral analysis. The variation in optical and luminescent response of the carbon dot suspension with the rate of centrifugation was also monitored. Furthermore, investigations on the photocatalytic response of as-synthesized carbon dots towards degradation of methylene blue and its activity as a potential antimicrobial agent against Escherichia coli are also presented.

Physicochemical and Volatile Compounds Analysis of Fruit Wines Fermented with Saccharomyces cerevisiae: FTIR and Microscopy Study with Focus on Anti-Inflammatory Potential.

The growing trend in fruit wine production reflects consumers' interest in novel, diverse drinking experiences and the increasing demand for healthier beverage options. Fruit wines made from kiwi, pomegranates, and persimmons fermented using S. bayanus Lalvin strain EC1118 demonstrate the versatility of winemaking techniques. Kiwifruit, persimmon, and pomegranate wines were analyzed using HPLC and GC-TOFMS analyses to determine their concentrations of phenolic acids and volatile compounds. These results were supported by Fourier transform infrared (FTIR) spectroscopy to characterize and compare chemical shifts in the polyphenol regions of these wines. The wines' characterization included an anti-inflammatory assay based on NO, TNF-alpha, and IL-6 production in the RAW 264.7 macrophage model. FTIR spectroscopy predicted the antioxidant and phenolic contents in the wines. In terms of polyphenols, predominantly represented by chlorogenic, caffeic, and gallic acids, pomegranate and kiwifruit wines showed greater benefits. However, kiwifruit wines exhibited a highly diverse profile of volatile compounds. Further analysis is necessary, particularly regarding the use of other microorganisms in the fermentation process and non-Saccharomyces strains methods. These wines exhibit high biological antioxidant potential and health properties, providing valuable insights for future endeavors focused on designing healthy functional food products.

Production of biodiesel from waste cooking oil using a novel surface-functionalized CaMoO4/ TiO2 solid catalyst

This study involves the synthesis of a mesoporous CaMoO4/TiO2 solid catalyst through the impregnation method. The catalyst, known for its novelty, efficiency, and recyclability, was thoroughly characterized using various techniques, including Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDAX), Thermogravimetric Analysis (TGA), Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) studies. Waste cooking oil is analysed using FTIR spectroscopy for its free fatty acid content. In addition, the specific catalytic activities are investigated under a variety of reaction conditions. A yield of 95.6 % is achieved under the standard trans esterification reaction operating parameters such as catalyst loading of 4 wt %, methanol to waste cooking oil molar ratio of 15:1 (v/v), reaction duration of 70 min, reaction temperature of 55 °C, stirring speed of 270 rpm, and temperature of calcination as 650 °C. The reaction kinetics (pseudo first order) is also studied. Solid catalysts can also be reused up to five successive times. Biodiesel is characterized by FTIR and 1H NMR studies to examine the presence of functional and methyl ester groups respectively, and the extracted biofuel met the specifications of ASTM D 6751 norms for standard diesel fuel.

Synthesis of nickel-cobalt ferrite/graphene oxide nanocomposites

Current investigation is an attempt to study the structural, optical, magnetic and dielectric properties of Ni0.5Co0.5Fe2O4/graphene oxide (NCF/GO) nanocomposites. NCF/GO nanocomposites were synthesized through the ultrasonication technique. NCF nanoparticles (NPs) and GO (with varying weight percentages of GO) were synthesized through sol–gel auto-combustion and modified Hummer’s method, respectively. The effect of nickel–cobalt ferrite NPs incorporation on graphene oxide was studied using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, field emission scanning electron microscopy (FESEM), vibrating sample magnetometer (VSM) and Impedance Analyzer. electrical and dielectric measurements. XRD and FTIR studies showed and confirmed the formation of both spinel for the NCF NPs and amorphous graphene oxide for NCF/GO nanocomposites. The crystallite size and lattice parameter for NCF NPs were found in the range of 21–47 nm and 8.33–8.36 Å, respectively. The optical band gap was found in the range of 1.73–1.83 eV with increasing GO concentration. VSM studies revealed that the saturation magnetization (Ms) value for NCF/GO nanocomposites is found to be decreased from 59 emu/g (for NCF) to 30 emu/g (for 60 wt% of GO) with increased GO weight percentage. There was a drastic variation observed in the value of coercivity (Hc) for NCF and NCF/GO nanocomposites. However, it remains almost constant within NCF/GO nanocomposites. Dielectric studies showed the exponentially decaying nature of dielectric constant and loss tangent with logarithmic frequency. Further, the dielectric constant is increased with increasing GO content. A maximum dielectric constant is observed for NCF/GO nanocomposites with 60 wt% of GO. The AC conductivity is found to be increasing with an increase in GO weight percentage and showed its sharply increasing nature at higher frequencies.

Fotocatalytic degradation of methylene blue by floating TiO2-coconut fiber

Indonesia's expanding industrial sector has resulted in an increase in the use of dyes. Methylene blue (MB), a dye used in the batik and textile industries, has the potential to be detrimental to people and the environment. Recent research indicates that the TiO2 photocatalyst has the ability to reduce MB. TiO2 transported in coconut fiber can improve illumination in the photocatalysis process. The purpose of this study is to examine the properties and activity of a TiO2-coconut fiber photocatalyst. SEM-EDX was used to characterize the morphology and composition of floating catalysts, and Fourier transform infrared (FT-IR) was used to characterize the functional groups. At 120 minutes, TiO2-coconut fiber photocatalysis with a mass ratio of 20:80 w/w demonstrated the maximum degradation of 62.72%. The SEM-EDX data demonstrate the morphology of TiO2 distribution on the surface of coconut fiber, which is distinguished by the presence of the main elements O, Ti, and C. The FT-IR study results demonstrate a shift and decrease in Ti-O absorption intensity from 756,09 cm1 to 721,38 cm1, indicating the presence of Ti-O-C bonds. It is hoped that this research will be useful in the treatment of MB in textile industry waste or other organic waste.

Evaluation of the binding properties of pectin isolated from <i>Citrullus lanatus</i> and <i>Cucumis sativus</i> peels in tetracycline capsule formulation

Background: The advent of science and technology has greatly enhanced the conversion of agro-industrial wastes into various value-added products to meet the demands of increasing population. The study evaluated the binding properties of pectin isolated from Citrullus lanatus and Cucumis sativus peels in comparison with carboxymethyl cellulose (CMC) and pectin BP in oxytetracycline capsule formulationsMethods: Pectin was extracted from Citrullus lanatus and Cucumis sativus peels using standard procedures. Extracted pectin was subjected to phytochemical, organoleptic and spectral analysis and then used to prepare batches of oxytetracycline granules and capsules. Granule flow, capsules properties and drug compatibility studies using Fourier transform infrared (FTIR) analysis were determined.Results: Phytochemical analysis of the powdered peels of C. lanatus and C. sativus showed the presence of alkaloid, saponin, terpenoid and carbohydrate. Percentage yield of pectin were 11.88 and 12.27% for C. lanatus and C. sativus, respectively. Oxytetracycline granules prepared exhibited the following micromeritic properties; Hausner’s ratios - 1.12 to 1.33; Carr’s indices - 11.11 to 32.61(%); angles of repose - 30.47 to 43.89° and flow rates - 1.17 to 5.67 g/sec. Disintegration times of formulated capsules were between 4.86 to 6.87 min and were within pharmacopoeial limits for capsules. FTIR studies showed no interaction between drug and excipients. Dissolution studies revealed decreased drug released with increase in binder concentration.Conclusion: Pectin extracted from the peels of C. lanatus and C. sativus fruits compared favourably with pectin BP and CMC in their binding properties, hence a suitable substitute binder in the formulation of oxytetracycline granules and capsules.

Effect of mango butter on the physicochemical properties of beeswax-Moringa seed oil-based oleogels for topical application

Objective The purpose of this research was to determine any connections between the characteristics of oleogels made of beeswax and the impact of mango butter. Methods Oleogel was prepared through inverted tube methods, and optimized through oil binding capacity. Other evaluations like bright field and polarized microscopy, Fourier-transform infrared (FTIR) spectroscopy, crystallization kinetics, mechanical study, and X-ray diffractometry (XRD). The drug release kinetic studies and in vitro antibacterial studies were performed. Results FTIR study reveals that the gelation process does not significantly alter the chemical composition of the individual components. Prepared gel exhibiting fluid-like behavior or composed of brittle networks is particularly vulnerable to disruptions in their network design. The incorporation of mango butter increases the drug permeation. In-vitro microbial efficacy study was found to be excellent. Conclusion The studies revealed that mango butter can be used to modify the physico-chemical properties of the oleogels.

Unveiling the effect of Pt addition on Ag/C catalyst for enhanced glycerol electrooxidation

This study investigates the performance of Ag/C and a range of Ag100-xPtx/C nanoparticles as electrocatalysts for glycerol electrooxidation reaction (GEOR). Low amounts of Pt (<2 %) were spontaneously deposited on Ag-supported nanoparticles using Ag as a sacrificial metal. The primary aim of the study is to determine the impact of adding a small amount of Pt to the Ag/C catalyst. Cyclic voltammetry is employed to assess the electrocatalyst's performance, while in situ Fourier Transform Infrared (FTIR) spectroscopy is used to examine the formed reaction intermediates and products. Additionally, physical characterization techniques such as XRD and XPS are applied to analyze the material structure. The Ag100-xPtx/C series of catalysts show a significant improvement in the glycerol oxidation process with the addition of 0.25 % of Pt to the material composition compared to pure Ag. It is observed that the enhancement performance reaches a limit at a Pt composition of approximately 7 % in the metallic nanoparticles, indicating that further increases in Pt content do not yield additional improvements. The in situ FTIR studies reveal that the presence of Pt on the Ag surface leads to a distinct glycerol electrooxidation mechanism compared to using Ag alone. Small amounts of Pt deposits promote C−C−C bond breaking, as evidenced by the selective formation of formic acid and CO2. FTIR results demonstrate a preference for carboxylic acid formation, with no significant evidence of dihydroxyacetone (DHA) production. The findings emphasize the critical role of Pt composition in the electrooxidation of glycerol paving the way for the design and development of more efficient and sustainable electrooxidation catalysts.

Understanding seawater-induced fatigue changes in glass/epoxy laminates: A SEM, EDS, and FTIR study

Composite polymeric materials have exhibited significant advantages when operating in hostile conditions such as the marine environment. However, there is a lack of information concerning three-dimensional variations induced by prolonged exposure to seawater in composite structures and their impact on fatigue performance. Thus, this study aims to investigate the effects of long-term exposure to natural seawater on both the fatigue strength and three-dimensional chemical changes of GFRP laminates. Fatigue tests were conducted under uniaxial cyclic loading at a stress ratio R = 0.1, considering three groups of specimens: a control group not immersed in natural seawater, a group immersed for 230 days in natural seawater, and a group immersed for 910 days in natural seawater. After the tests, fracture surfaces were analysed using scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). SEM examination revealed the microstructural occurrence of fibre-matrix debonding, reducing the load transfer between the fibre and matrix, contributing to the fatigue life decrease in immersed specimens. The fatigue results revealed that the reduction in fatigue life of the specimens immersed for 230 days was approximately 66 % of that observed in the control specimens increasing to 95 % when the immersion period extended to 910 days. Moreover, the effect of immersion time on the chemical structure of various regions within the specimens was assessed using Fourier-transform infrared (FTIR) spectroscopy. The main findings suggest the existence of a concentration gradient within the laminate and that regions near permeable surfaces are more vulnerable to chemical changes compared to regions located further away, even after reaching saturation.

Green synthesis of copper nanoparticles by using pineapple peel waste: in vitro characterizations and antibacterial potential.

A considerable amount of fruit waste is being produced every day worldwide. The green synthesis of metal nanoparticles from fruit peel waste can be an innovative, cost-effective, and eco-friendly alternative to traditional methods. Copper nanoparticles (CuNPs) were synthesized by a green method using the pineapple peels extract (PLX) and copper sulfate pentahydrate. The formation of CuNPs was visually identified and detected by UV-Visible spectroscopy. The CuNPs were characterized by Fourier-transform infrared (FTIR) spectroscopy, particle size analyzer, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The antioxidant and reducing power of CuNPs were conducted by %DPPH scavenging and electron transfer-based ferric reducing antioxidant power (FRAP) assay, respectively. The antibacterial properties of CuNPs were determined in gram-positive, and gram-negative bacteria. The results showed that the CuNPs were spherical in shape with mean particle size 290.5nm. The zeta potential of the nanoparticles was found to be -12.3mV indicating the instability in the colloidal state. The FTIR study confirmed the peaks of phytochemicals present in the PLX and the nanoparticles supporting the use of pineapple peels as stabilizing, reducing and capping agents. Both the DPPH and reducing power assay depicted that the synthesized CuNPs had significant antioxidant activity. However, the synthesized CuNPs had strong inhibitory capacity against both gram-positive and gram-negative test organisms. Thus, the CuNPS could be used for its viable antibacterial potential to preserve fruits, flowers, and vegetables from bacterial contamination.

Effect of bovine serum albumin on gallic acid and tannic acid radical scavenging properties and binding kinetics with 2,2-diphenyl-1-picrylhydrazyl

A detailed study on gallic acid (GA), tannic acid (TA) antioxidant properties, and binding kinetics with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) in the presence of bovine serum albumin (BSA) was performed using electronic absorption (UV/Vis), fluorescence, and Fourier transform infrared (FTIR), spectroscopy methods. The effective concentration (EC50), antioxidant reducing power (ARP), stoichiometry (EC100), and the number of reduced DPPH˙(n) were determined using the DPPH˙ assay. It was shown that the antioxidant efficacy of GA/TA reduces slightly in the presence of BSA. However, the duration of the antioxidant activity of GA/TA increases as a result of the complex formation with BSA. The concentration of free and BSA-bound GA/TA was determined using fluorescence spectra. The rate constant (kobs), which describes the main reaction between antioxidant and DPPH˙, and the second-order rate constant (k2) were determined. FTIR studies showed that the binding of GA/TA with BSA causes conformational changes in the secondary structure of the protein (decrease of α-helixes, an increase of β-sheet structures). Moreover, TA induces more pronounced effects compared to GA.

Reducing Time and Costs of FT-IR Studies of the Effect of SiNx, Dopants, and Emitter on Hydrogen Species in Si Wafers and Solar Cell Structures

Accurately measuring the hydrogen content in silicon (Si) solar cells is essential due to its connection to surface degradation and light and elevated temperature induced degradation (LeTID). Fourier Transform-Infrared (FT-IR) spectroscopy provides a quantitative technique for determining the content of various hydrogen species in Si wafers that have undergone various process steps. In this study, we examine both the effect of a silicon nitride (SiNx:H) layer during FT-IR spectroscopic measurements on hydrogen species, as well as the impact of an emitter present during firing on the amount of hydrogen introduced into Si wafers. We find that the presence of SiNx:H during measurements has negligible effects on the measured hydrogen species, potentially simplifying the preparation steps for FT-IR. For the emitter investigation we analyze boron (B)- and gallium (Ga)-doped p-type wafers to detect H-B, H-Ga, Oi-H2, and H2. We observe that hydrogen species initially present in B- and Ga-doped Si wafers differ significantly. Only H-Ga is detected in Ga-doped wafers, while H-B, Oi-H2, and H2 signals are measured in B-doped wafers. Moreover, we cannot confirm an increased release of H through the emitter into the bulk during the firing process. Finally, we conduct measurements at different temperatures and confirm that cryogenic temperatures are more effective for detecting H-B and H2 with concentrations in the 1014 cm-3 range. Nevertheless, useful spectra can still be obtained at liquid nitrogen (N2) temperatures.

Novel Chitosan-Coated Liposomes Coloaded with Exemestane and Genistein for an Effective Breast Cancer Therapy.

For achieving high effectiveness in the management of breast cancer, coadministration of drugs has attracted a lot of interest as a mode of therapy when compared to a single chemotherapeutic agent that often results in reduced therapeutic end results. Owing to their proven effectiveness, good patient compliance, and lower costs, oral anticancer drugs have received much attention. In the present work, we formulated the chitosan-coated nanoliposomes loaded with two lipophilic agents, namely, exemestane (EXE) and genistein (GEN). The formulation was prepared using the ethanol injection method, which is considered a simple method for getting the nanoliposomes. The formulation was optimized using Box-Behnken design (BBD) and was extensively characterized for particle size, ζ-potential, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analysis. The sizes of conventional and coated liposomes were found to be 104.6 ± 3.8 and 120.3 ± 6.4 nm with a low polydispersity index of 0.399 and 0.381, respectively. The ζ-potential of the liposomes was observed to be -16.56 mV, which changed to a positive value of +22.4 mV, clearly indicating the complete coating of the nanoliposomes by the chitosan. The average encapsulation efficiency was found to be between 70 and 80% for all prepared formulations. The compatibility of the drug with excipients and complete dispersion of the drug inside the system were verified by FTIR, XRD, and DSC studies. Furthermore, the in vitro release studies concluded the sustained release pattern following the Korsmeyer-Peppas model as the best-fitting model with Fickian diffusion. Ex vivo studies showed better permeation of the chitosan-coated liposomes, which was further confirmed by confocal studies. The prepared chitosan-coated liposomes showed superior antioxidant activity (94.56%) and enhanced % cytotoxicity (IC50 7.253 ± 0.34 μM) compared to the uncoated liposomes. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay displayed better cytotoxicity of the chitosan-coated nanoliposomes compared to the plain drug, showing the better penetration and enhanced bioavailability of drugs inside the cells. The formulation was found to be safe for administration, which was confirmed using the toxicity studies performed on an animal model. The above data suggested that poorly soluble lipophilic drugs could be successfully delivered via chitosan-coated liposomes for their effective delivery in breast cancer.

Green Synthesis of Aluminum Oxide Nanoparticles Using Clerodendrum phlomidis and Their Antibacterial, Anti-inflammatory, and Antioxidant Activities.

Clerodendrum phlomidisplays a significant role in many indigenous medical systems, and it can be mostly found in Southeast Asia. The objective of the study was to synthesize and characterize the biosynthesized aluminum oxide nanoparticles (AlO-NPs) usingC. phlomidisand analyze their antibacterial (bactericidal), antioxidant, and anti-inflammatory activities. The extract was prepared by the autoclave-assisted method, and the AlO-NPs were synthesized by the green synthesis method. The biosynthesized AlO-NPs were characterized by ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray (EDX) analysis. The antibacterial property was assessed by the Kirby-Bauer well diffusion method, and the antioxidant activity was checked by DPPH (2,2-diphenyl-1-picrylhydrazyl) activity compared with the control L-ascorbic acid. Anti-inflammatory activity was evaluated by an albumin denaturation assay, and diclofenac was used as a control. IBM SPSS Statistics for Windows, Version 21.0 was used for the statistical analysis. Results: An absorption peak at a wavelength of 380 nm was detected by UV-Vis spectroscopy analysis. It proves that AlO-NPs have been successfully produced by the green synthesis method. The results of the FT-IR study demonstrated the existence of numerous chemicals and functional groups in the 500-3500 cm-1range. AlO-NPs from the plant extract were subjected to FE-SEM analysis, which revealed an aggregated or spherically cluster-like structure. The sample's elemental makeup, which revealed that it included 38% aluminum and 28% oxygen, was identified with the help of the EDX, and this verified the high purity of the AlO-NPs. The results of the antibacterial activity of AlO-NPs revealed that there was a zone of inhibition forEnterococcus faecalis;however, there was no zone of inhibition forStreptococcus mutans. The synthesized AlO-NPs exhibit strong antioxidative (DPPH activity) and anti-inflammatory (albumin denaturation assay) action. In this work, the in vitro antioxidant activity ofC. phlomidiswas assessed using the standard, L-ascorbic acid, as a measure of DPPH activity. At a maximum concentration of 500 µg/ml, the obtained results showed the incredible antioxidant properties of the investigated AlO-NPs synthesized from the plant extracts and demonstrated 90% inhibition. AlO-NPs that were biosynthesized showed effective anti-inflammatory activity at a higher concentration of 100 µg/ml and demonstrated 89% inhibition in contrast to the drug diclofenac sodium. According to the study's findings, AlO-NPs made using a greener synthesis approach have the potential to be used in a variety of industries and are also an affordable and sustainable way to effectively act as anti-inflammatory and antioxidant agents.

DEVELOPMENT, CHARACTERIZATION AND PHARMACOKINETIC EVALUATION OF OPTIMIZED VILDAGLIPTIN SUSTAINED RELEASE MATRIX TABLET USING BOX-BEHNKEN DESIGN

Objective: The principal objective of this research was to develop and optimize cost-effective sustained-release Vildagliptin (VLN) tablets using the wet granulation method. Methods: The tablets were prepared by the non-aqueous wet granulation method. A Box-Behnken design was used to study the effect of the independent variables, i.e., HPMC K100 M, Eudragit RSPO and PVP K30, on the dependent variables swelling index, in vitro drug release at 8 and 12 h. The drug's physiochemical properties were investigated using ultraviolet (UV), Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). The hardness, thickness, weight variation, content uniformity, swelling index, and in vitro drug release study of the formulated tablets were all evaluated. The optimized formulation Opt-VLD-SR was evaluated for pharmacokinetic parameters like AUC, Cmax, tmax and MRT. Results: The FTIR and DSC studies confirmed that no interaction occurred between the drug, polymers and excipients. The crystalline nature of VLN remained unchanged in the optimised formulation tablet, according to DSC studies. With the optimal concentration of both polymers, formulation Opt-VLN delayed drug release for up to 12 h. The formulated Optimized Sustained-release tablets (Opt-VLD-SR) showed significantly lower Cmax±3.01ng/ml) than conventional IR tablets (256.17±8.02ng/ml). In the pharmacokinetic study, the MRT for Optimized-VLD-SR is (7.40h) showed a better result than the Vildagliptin IR marketed product (3.70 h.), which leads to higher bioavailability of Vildagliptin. Conclusion: Sustained release tablets of VLN with a combination of diffusion and erosion-controlled drug release mechanisms have been successfully developed.

Critical evaluation of silver nanoparticles synthesized at room temperature/microwave irradiation: A green approach

Biological routes of nanoparticle synthesis, especially the use of plant-based extracts, have shown great potential for the production of silver nanoparticles (Ag NPs). Ag NPs synthesized in this way is a simple one-step method that is economical and environmentally friendly. With the increasing need to develop new and effective antibacterial agents, a novel and stable Ag NPs is synthesized using aqueous seed extract of Strychnos potatorum (SP). Ag NPs obtained at room temperature (S1) and under optimal microwave irradiation (S2) were compared in the present work. The as-synthesized Ag NPs are characterized by Ultraviolet-Visible (UV-Vis) spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). UV-Vis spectra showed Surface Plasmon Resonance (SPR) peaks at 430nm (S1) and 438nm (S2) associated with the formation of Ag NPs. XRD patterns indicate the crystallinity of Ag NPs, with an average crystallite size of approximately 23nm (S1) and 15nm (S2). FT-IR study revealed potential biomolecules to form Ag NPs. FESEM and TEM analysis revealed the spherical shape of Ag NPs. An average particle size of approximately 31nm (S1) and 19nm (S2) was revealed from TEM analysis. To the best of our understanding, this study is novel as Ag NPs synthesized from SP using a microwave oven are described in detail for the first time. The study also demonstrated the potential of Ag NPs for antibacterial effect against Gram-positive bacteria (Streptococcus pneumoniae, Staphylococcus aureus) and Gram-negative bacteria (Klebsiella pneumoniae, Vibrio vulnificus). Our findings show that at a specific concentration, small NPs are more efficient in inhibiting bacterial activity. This research indicates that Ag NPs synthesized from SP exhibit strong antibacterial activity for the treatment of bacterial infection.

Effect of oxygen partial pressure on phase, local structure and photoluminescence properties of Hf(1-x)YxO2 thin films prepared by pulsed laser deposition

Hf(1-x)YxO2 (x = 0, 0.10, 0.15, 0.20) epitaxial thin films on YSZ(100) substrate were prepared at different oxygen (O2) partial pressures (100, 70, 30, and 10 sccm) by pulsed laser deposition. The effect of oxygen partial pressure on crystalline and local structure was investigated using X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) and X-ray absorption spectroscopy (XAS). The surface composition was determined by X-ray photoelectron spectroscopy. The XRD and FTIR studies reveal that undoped HfO2 thin films remain in monoclinic phase, and the Hf0.85Y0.15O2 & Hf0.80Y0.20O2 films stabilize in cubic phase at all oxygen pressures, whereas the structure of Hf0.90Y0.10O2 films changes from orthorhombic to cubic as oxygen pressure reduces from 100 sccm. The XAS at Hf-L3 edge and O K-edge shows the changes in bond distances, disorder and hybridization. In monoclinic HfO2 films the Hf–O bond distance and disorder increases and Hf–Hf bond decreases as the O2 partial pressure decreases, whereas disorder in doped films shows anomalous behaviour. The oxygen vacancies are evident from both XAS and photoluminescence studies. The results enlighten a deeper understanding of phase change, local structure, optical properties and pave a way to stabilize and identify different technologically important HfO2 phases for dielectric and ferroelectric applications.

Spectroscopic FTIR study for pathway of ribose formation via formose reaction in Astrochemistry

Ribose is one of the crucial molecular species in the study of the origin of life as it is the backbone of ribonucleic acid (RNA). On the early Earth, sugars including ribose are thought to be formed through formose reaction. Ribose and other organic molecules were also found in meteorites, signifying their existence in interstellar space, providing them with the essential components for prebiotic chemistry. The formose reaction can produce a mixture of simple sugars from formaldehyde molecules. In our study, we successfully synthesized sugars using the formose reaction under both thermal conditions and microwave irradiation. Notably, sugars were obtained within a remarkably short duration of 1 minute under microwave irradiation. The identification and characterization of the synthesized products were achieved through Fourier transform infrared (FTIR) spectroscopy and Fehling’s test, confirming the successful synthesis of sugars and the presence of aldehyde and alcohol functional groups. In addition, we propose an alternative pathway for sugar synthesis, which holds promise for further exploring the formose reaction in astrochemical experiments.