Fourier Transform Infrared Studies Research Articles

Investigation of intrinsic electrical properties of cerium doped lithium cobalt oxide, nanostructured materials

Cerium doped lithium cobalt oxide LiCo1−xCexO2 (0≤x≤0.08) compositions have been synthesized by a modified ‘Pechini’ process. The structural and electrical properties of the doped compositions were investigated through XRD, FTIR, EDX, Raman, and (EIS) experiments. X-Ray Diffraction (XRD) analysis established the formation of single phase crystalline nature of the synthesized powders. Ce doped samples crystallized in the R3m space group, with expansion along the ‘c’ lattice. Whereas scanning electron microscopic (SEM) analysis revealed that due to Ce doping the microstructure has altogether changed, with the presence of grains and grain boundaries. Raman and FTIR (Fourier transform infra-red) studies assisted to attribute ordered crystalline realms within the lattice. Energy Dispersive X-ray (EDX) confirmed the presence of no additional peak thus ruling out the presence of impurities. In order to discover the effects of the altered microstructure and existence of the crystalline domains on the resistive and dielectric properties all the compositions were exposed to EIS (electrical impedance spectroscopy) study at room temperature and in wide frequency range. Electrical properties demonstrated that LiCo1−xCexO2 (x = 0.04 and 0.06) had more resistance in comparison to x = 0 and 0.08 compositions. According to crystal field splitting theory, incoming electron from the doped metal created an insulating phase responsible for the enhanced resistance. Modified Debye behavior was exhibited by frequency dependent dielectric measurements at room temperature. As a result of tailored properties LiCo1−xCexO2 compositions can be used in high frequency devices.

Sticky hydrophobic behavior of cellulose substrates impregnated with alkyl ketene dimer (AKD) via sub- and supercritical carbon dioxide

Cellulose fibers were impregnated with alkyl ketene dimer (AKD) dissolved in n-heptane and carbon dioxide via sub- and supercritical impregnation techniques. The mechanistic pathways and hydrophobic performance at short and long times were investigated by contact angle (CA) analysis, scanning electron microscopy (SEM) with micrographs analyzed using Image-Pro Premier, and Fourier Transform Infrared (FTIR) analysis. The sizing development was significant after two days of treatment, and hydrophobic performance became uniform after two weeks regardless of the impregnation conditions investigated. Samples prepared at 100 and 200 bar produced more rapid development than those at higher and lower impregnation pressures, with the average CA at 200 bar and 21 °C being 140 ± 5°. ‘Sticky’ hydrophobicity was observed on surfaces treated at 200 and 250 bar at long times (> 140 days), and adhesive forces between the droplet (>20 μL) and surface were observed at surface tilt angles between 0 – 180°. SEM micrographs of the impregnated samples showed a reduction in substrate pore-size area (PSA) as hydrophobicity developed with time. There was little evidence of reaction-based sizing as the characteristic ketone and ester peaks were not observed in FTIR studies. The lactone ring remained intact. The 200 bar sample showed highest peak intensity for various hydrocarbon bonds observed – suggesting the optimal solubility of AKD in supercritical carbon dioxide (scCO2). Spreading of AKD across the fiber surfaces appeared to be the main sizing pathway, and identification of hydrogen bonding between AKD and cellulose fibers suggested a possible attachment method.

FTIR and rheological studies of PMMA-based nano-dispersed gel polymer electrolytes incorporated with LiBF4 and SiO2

Gel polymer electrolytes (GPEs) were prepared by dissolving lithium tetrafluoroborate (LiBF4) salt, poly(methylmethacrylate) (PMMA) polymer and distinct non-volatile solvents propylene carbonate (PC), and -N,N-dimethylformamide (DMF) in single as well as binary solvent mixtures. Ionic conductivities of 8.93 mS/cm and 6.68 mS/cm at 25 °C have been obtained for gel polymer electrolytes for 10 wt% PMMA in the solution of LiBF4 in binary solvent mixture of PC:DMF in (1:1) and (2:1) volume ratios respectively. The dispersion of nano-sized silica in gel polymer electrolyte not only exhibits small change in ionic conductivity but also enhances the mechanical strength as well as viscosity of gel polymer electrolytes. At room temperature, the ionic conductivity has been found to be 8.00 mS/cm for 6 wt% nano-sized silica in GPEs. Fourier-transform infrared (FTIR) spectroscopic studies have been used to scrutinize the corroboration of the complexation between PMMA, LiBF4, PC, DMF, PC:DMF, and SiO2. The interactions between salt and solvents in liquid electrolytes have also been analyzed by FTIR spectroscopy illustrating the strong interaction between lithium salt and solvent molecules. The appearance/disappearance and shifting of some peaks confirm the interaction among the constituents of nano-dispersed gel polymer electrolytes. The mechanical strength was confirmed by dynamic mechanical analysis (DMA) and viscosity [ηPC:DMF (2:1) > ηPC:DMF (1:1) > ηPC] for nano-dispersed silica-based gel polymer electrolytes. The electrical and mechanical stability with high ionic conductivity for such gel polymer electrolytes makes these electrolytes suitable for many device applications like high energy density lithium-ion batteries, super-capacitors, electro-chromic devices etc.

FTIR study of Achilles tendinopathy: protein secondary structure changes in tendon post injury

Abstract Introduction Tendinopathy, a disease involving tendon inflammation and damage, results in considerable productivity and economic losses for the patient and the society. Currently available diagnosis/ treatment monitoring modalities are less efficacious and highly subjective, underlying the need for better tools. Previously, we have shown that Fourier Transform Infrared (FTIR) spectroscopy has potential in tendinopathy diagnosis/ monitoring, when combined with multivariate statistical analysis. The current study explores the spectral range that gave the best results in statistical analysis, to discover protein secondary structures associated with tendon injury and recovery that can act as markers of disease. Methods Animals (n=60) underwent a surgery in which Achilles tendon were injured by dropping a 20g weight. Rats were divided into three groups (n=20) – control (C), Achilles tendon injury (I) and Achilles tendon injury treated with amniotic membrane fragment treated (T). FTIR spectra were obtained from each group 3, 7, 14, and 28 days post injury/ treatment. Results Triple helix, β-turn, and disordered structure levels differ between control, injured and treated tendons over the time period studied. Parallel β-sheets increase steadily over time in treated tendons compared to control and injured. Conclusion Combined analysis of Triple helix, β- sheets, β-turn, and disordered structure levels may be useful for tendinopathy diagnosis and treatment monitoring. However, further studies in this area are required to confirm the findings.

FORMULATION AND EVALUATION OF FAST DISSOLVING FILM OF LORNOXICAM

Objective: The aim of the present work was to formulate and evaluate fast dissolving film containing lornoxicam.Materials and Methods: To prepare the film, hydroxypropyl methylcellulose E5 and polyvinyl alcohol (PVA) were used as film-forming polymers by solvent casting method. Glycerine was used as plasticizer, aspartame, and mannitol as sweetener. All prepared films were evaluated for its weight variation, disintegration time, thickness, drug content, pH, dissolution study, and folding endurance. The drug-excipients compatibility study was done using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR).Results: Satisfactory results obtained when PVA was used as film-forming polymer, and the drug was dispersed in the polymer solution using poloxamer 407 as a solubilizing agent. Formulation F2 is considered as the optimized formulation as it showed good folding endurance (>300), faster disintegration rate (30 s), and maximum in vitro drug release (87%) within 5 min. DSC and FTIR studies showed no interaction between drug and the polymers.Conclusion: It can be concluded from the study that the fast dissolving film can be prepared for poorly water-soluble drug lornoxicam using PVA as a suitable film-forming polymer.

Synthesis, Structural and Optical Investigation of CdSe semiconductor Quantum Dots

In this paper, we present a simple synthetic route for the development of high quality CdSe quantum dots TGA capped in aqueous solutions. CdSe semiconducting Quantum dots were prepared by a chemical method at room temperature. The crystal structure, morphology, spectral and compositional properties were analyzed from powder X-ray Diffraction, High resolution transmission electron microscopy (HRTEM), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-Vis absorbance and Photoluminescence (PL), Fourier transform infrared (FTIR) and Fourier transform RAMAN (FT-RAMAN) techniques. The XRD results depicted the formation of CdSe quantum dots with the average crystallite size of 3 nm and 4 nm, which is in accordance with observations from HRTEM and TEM micrographs predict an average particle diameter of the QDs range between 2-3 nm. The UV-Vis absorbance peaks indicate the broad absorption behavior of the synthesized CdSe quantum dots. The calculated band gap energy was 2.55 eV and further it is found the particle size estimated from the maximum excitonic peaks for CdSe 2.7 nm. The photoluminescence studies evidenced that the luminesce property of quantum dots can be varied by systematically tuning precursor concentrations. The PL emission spectrum depicts the strong excitation peaks for the synthesized CdSe QDs with peaks centered at 603 nm. The capping of TGA was confirmed from FTIR and FT-RAMAN studies. From the FTIR spectra it is observed that, for the synthesized CdSe QDs almost all the peaks are common with slightly shifting behavior towards larger and shorter wave numbers. FT-Raman analysis was performed to study the sample qualities such as microcrystallinity, homogeneity and surface conditions for the as synthesized CdSe quantum dot. The resulting colloids are very stable, and no precipitate is observed over a period of 6 months.

Green synthesis of copper oxide nanoparticles and mosquito larvicidal activity against dengue, zika and chikungunya causing vector Aedes aegypti.

In the present study, high purity copper oxide nanoparticles (NPs) were synthesised using Tridax procumbens leaf extract. Green syntheses of nano-mosquitocides rely on plant compounds as reducing and stabilising agents. Copper oxide NPs were characterised using X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR), Field-emission scanning electron microscopy with energy dispersive spectroscopy, Ultraviolet-visible spectrophotometry and fluorescence spectroscopy. XRD studies of the NPs indicate crystalline nature which was perfectly matching with a monoclinic structure of bulk CuO with an average crystallite size of 16 nm. Formation of copper oxide NPs was confirmed by FT-IR studies and photoluminescence spectra with emission peaks at 331, 411 and 433 nm were assigned to a near-band-edge emission band of CuO in the UV, violet and blue region. Gas chromatography-mass spectrometry studies inferred the phytochemical constituents of the leaf extract. Larvicidal activity of synthesised NPs using T. procumbens leaf extract was tested against Aedes aegypti species (dengue, chikungunya, zika and yellow fever transmit vector).

Fast Fourier infrared spectroscopy to characterize the biochemical composition in diatoms

Diatoms are photosynthetic unicellular microalgae and are nature's hidden source of several biosynthetic metabolites with their use in biofuel, food and drug industries. They mainly contain various lipids, sterols, isoprenoids and toxins with their use in apoptotic, fertility controlling and cancer drugs. Chemical studies on diatoms are limited due to various limitations such as variation of nutrients, contaminants and change in seasonal factors in the environment. To overcome these limitations, we obtained axenic cultures of 12 fresh-water diatom strains on the 22nd day of inoculation having a dry weight of 1 mg each and performed their Fourier transform infrared (FTIR) study for the detection of functional groups responsible for their chemical moiety. The spectral mapping showed a varied level of polyunsaturated fatty acids, amides, amines, ketone bodies and esters for their applications in various pharmacological, food and biofuel industries in the exponential phase of their growth in f/2 media. The FTIR study of the 12 diatom strains showed various similarities in the form of some common peak patterns ranging from 3000 to 3600 cm-1 for vO-H absorption. The symmetric stretching vibration frequency of Diadesmis confervaceae (V2) type species showed different behaviour than others in the spectral region starting from 1600 to 1700 cm-1. The absorption between 1500 and 1575 cm-1 reflects the presence of the -N-H group. Infrared (IR) absorptions falling between 1600 and 1700 cm-1 reflect the presence of amide's vC=O in all species. Placoneis elginensis (V8) type species showed an additional absorption band which is centred around 1735-1750 cm-1 which perhaps reflects the presence of ester's vC=O. Diadesmis confervaceae (V2), Nitzschia palea (V4), Placoneis elginensis (V8), Nitzschia palea var. debilis (V6), Nitzschia inconspicua (V10), Gomphonema parvulum (V11) and Sellaphora (V12) showed distinct structural features with important key functionalities that can make them essential drug markers in the pharmaceutical industry.

FORMULATION AND DEVELOPMENT OF IN SITU FORMING GEL FOR THE TREATMENT OF ORAL THRUSH

Objective: The objective of the present work was to develop an in situ gel composed of Pluronic F-127, Carbopol 934, and methylparaben and loaded with fluconazole using DoE software to sustain the delivery of drug in the buccal cavity.Methods: In situ gels were prepared by temperature-induced method, by employing DoE and characterized by Fourier transform infrared (FTIR), differential scanning calorimeter (DSC), and evaluated for gelation temperature, gelation time, adhesive force, and in vitro diffusion studies.Results: Both FTIR and DSC studies suggested that there were no chemical interactions present between both drug and polymers. The formulated gels S1, S3, and S9 showed gelation at a body temperature. The viscosity, gel strength, and mucoadhesive force for the formulated in situ gels were found to be within the ranges of 375–738 cps, 35–62 s, and 4650–5210.32 dynes/cm2, respectively. The in vitro diffusion studies indicated that optimized in situ gel S3 exhibited the improved ability to sustain the drug compared to other formulations.Conclusion: Thus, developed in situ gel system was determined to be effective in terms of eradication of oral thrush.

Remarkable Ti-promotion in vanadium doped anatase titania for methylene blue adsorption in aqueous medium

We report here the synthesis of vanadium (5–20 at.%) doped titania and the pristine oxides via surfactant assisted coprecipitation method using cetyltrimethylammonium bromide as the surfactant and investigated their adsorption behavior towards hazardous methylene blue dye. The formation of anatase phase in all the doped materials is confirmed by the powder x-ray diffraction (P-XRD) analysis as corroborated by the Fourier transform-infrared (FT-IR) analysis, with particle sizes in the range 8–11 nm. Pure titania doesn’t show any adsorption property, but its presence enhances the adsorption property of vanadia considerably suggesting a promoting role of titania in the doped materials. The 10 at.% V-doped material, V0.1Ti0.9O2 is found to exhibit the best adsorption behaviour. The low resolution transmission electron microscopy studies reveal homogeneous nature, while ring type electron diffraction pattern suggests polycrystalline nature of the material. The high resolution transmission electron microscopy analysis suggests formation of single phase oxide. Kinetic and equilibrium studies have revealed the pseudo-second-order kinetics and Langmuir isotherm nature for this physisorption process. The pH dependency and recycling ability of this material have been discussed. Finally, X-ray photoelectron spectroscopy, FT-IR and P-XRD studies have been applied to understand the mechanism of regeneration of the material.

Synthesis Conditions on the Nature of GdBO3 Phase Formed

AbstractPresent study has been carried out to develop a facile synthetic methodology for preparing single phase monoclinic and triclinic forms of GdBO3, a potential phosphor material. This is achieved by varying annealing temperatures and annealing steps. Detailed structural studies, using X‐ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopic techniques confirmed that, Gd3+‐boric acid complexes formed initially at low temperatures (300 °C or less) get converted to monoclinic and triclinic forms of GdBO3 depending upon annealing temperatures, annealing steps and heating rates. Multiple steps with slow heating rates (∼3 °C/min) lead to the formation of single phase triclinic form of GdBO3. Two step heating with relatively faster heating rates (5 °C/min and above) results in single phase monoclinic GdBO3. FTIR and Raman studies also confirmed that boron exists only as BO4 structural units (in the form of B3O93− rings) in monoclinic GdBO3 and as BO3 structural units in triclinic GdBO3. Luminescence studies carried out with Eu3+ as a probe species confirmed more covalent nature around Eu3+/Gd3+ ions with improved red colour emission from triclinic form of GdBO3 compared to the monoclinic form.

DEVELOPMENT AND IN VIVO EVALUATION OF MUCOADHESIVE MICROSPHERES USING PIRENZEPINE

Objective: The current investigation objective was to fabricate gastroretentive mucoadhesive microspheres of pirenzepine and to investigate the pharmacokinetic parameters of optimized formulation in comparison with a marketed product.Methods: Pirenzepine mucoadhesive microspheres prepared using ionotropic gelation technique. Evaluation parameters and characterization such as Fourier transform infrared (FTIR) and scanning electron microscopy were performed. In vivo bioavailability studies were conducted in rabbits. The technique used was found to be handling easy, inexpensive, and reproducible process.Results: Among the total 14 formulations, M13 formulation was optimized and showed free flowing with good packability. FTIR studies investigated incompatibility were not observed between drug and excipients. The optimized formulation (M13) showed best cumulative percentage drug release of pirenzepine up to 99.07±0.17% within 12 h whereas marketed product displayed the drug release of 95.23±0.21% within 1 h. The release mechanism from microspheres followed the zero-order and Korsmeyer–Peppas model (R2=0.951 and 0.994), respectively. Optimized formulation (M13) was stable at 40°C±2°C/75% RH±5% RH for 6 months. Form in vivo studies, the optimized formulation bioavailability was much higher than the marketed product.Conclusion: Microspheres would be a promising drug delivery system could play a potentially significant role in pharmaceutical drug delivery in a controlled manner for an extended period of time for effective management of gastritis.

Combined In Situ XAFS and FTIR Study of the Hydrodeoxygenation Reaction of 2-Methyltetrahydrofuran on Ni2P/SiO2

This paper deals with a study of the mechanism of hydrodeoxygenation (HDO) at 0.1 MPa and 300–350 °C of 2-methyltetrahydrofuran (2-MTHF) over a Ni2P/SiO2 catalyst. The study was conducted using in situ Fourier transform infrared (FTIR) spectroscopy to monitor the adsorbed species during reaction and in situ X-ray absorption fine structure (XAFS) to probe the oxidation state of the Ni component. The work is relevant to the upgrading of bio-oil derived from the pyrolysis of biomass. It was deduced that the initial interaction of the 2-MTHF was with OH groups on the catalyst surface, followed by adsorption on Ni sites. Ring-opening of the tetrahydrofuran led to the formation of the main products of the reaction, n-pentane by HDO and n-butane + CO by decarbonylation. The CO band appeared with a slight delay in the FTIR spectrum because the reaction to form n-pentane was favored and turned over about four times before one n-butane + CO was formed.

Preparation and characterization of artemether loaded solid lipid nanoparticles: a 32 factorial design approach

ABSTRACT This study represents preparation and characterization of solid lipid nanoparticles (SLNPs) containing artemether. Nano-emulsion technique was employed to produce artemether loaded SLNPs. 2-factor 3-level design was employed to observe the effect of independent variables on dependent variables. 2D counter plots and 3D surface response plots were drawn and based on desirability factor the optimized formulation was selected. The X-ray diffraction (XRD) pattern and Fourier Transform Infrared (FTIR) spectroscopy of SLNPs were performed to check the compatibility of artemether with lipid. The optimized formulation shows average particle size 692.6 nm with smooth surface. Prepared formulation shows encapsulation efficiency in the range of 58.31% to 78.69% and maximum 82.23% drug release over a period of 30 h. The FTIR study shows no drug-excipients interaction. The artemether loaded SLNPs were successfully prepared with good encapsulation efficiency to achieve improved bioavailability and controlled drug release.

Synthesis of silver nanoparticles (AgNPs) from cinnamon against bacterial pathogens

Abstract Nanotechnology can be useful in diagnostic techniques, drug delivery, sunscreens, antimicrobial sanitizer and a friendly manufacturing process that reduce waste products. Development of Green Nanotechnology is generating interest of researchers towards eco-friendly biosynthesis of nanoparticles. In the research study silver nanoparticles were synthesized from aqueous silver nitrate (1 mM) through a simple and eco-friendly method using cinnamon as reductant and stabilizer. The aqueous silver ions when exposed to leaf broth were reduced and resulted in the green synthesis of silver nanoparticles ranges from 20 nm to 30 nm. The bio reduced silver nanoparticles were characterized by UV–Vis spectrophotometer, X ray diffraction, FESEM with EDAX and Fourier transform infra red (FTIR) spectroscopy. The FTIR study was carried out to recognize the possible biomolecules responsible for proficient stabilization of silver nanoparticles and their antimicrobial activity was screened against both gram positive, gram-negative microorganisms. The method can be used for rapid and eco-friendly biosynthesis of stable silver nanoparticles of size range from 20 to 30 nm possessing antimicrobial activity suggesting their possible application in the field of medicine.

Chemically synthesized 3D nanostructured polypyrrole electrode for high performance supercapacitor applications

Three-dimensional (3D) polypyrrole (Ppy) electrodes are directly grown on Ni foam using a solution-based cost effective chemical method and an in situ controlled precipitation route for supercapacitor application. The Ppy electrodes are characterized for their structural and morphological studies using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy. The XRD study revealed that Ppy electrodes are amorphous. SEM shows the formation of tiny spherical grains spread over the entire electrode surface. The FT-IR study confirms the formation of Ppy film on the electrode surface. The supercapacitive performance of the Ppy electrode using the cyclic voltammetry technique in a 3M KOH electrolyte shows a maximum specific capacitance of 931 F/g at a scan rate of 5 mV/s. Performance analysis of the supercapacitive electrode carried out using electrochemical impedance spectroscopy (EIS). A distorted semicircle in the high frequency region of EIS shows reduction in charge-transfer resistance.

The Production of Methane, Acetone, "Cold" CO and Oxygenated Species from IsoPropyl Alcohol in a Non-Thermal Plasma: An In-Situ FTIR Study.

This paper reports in situ Fourier transform infrared (FTIR) spectroscopic studies on the nonthermal plasma reaction of isopropyl alcohol in dinitrogen at Macor (a ceramic containing oxides of Al, Mg, and Si) and the analogous thermally driven process. While isopropyl alcohol did not react at the Macor at temperatures up to 600 °C, the study of the nonthermal plasma-driven process at the ceramic led to unexpected chemistry hitherto not observed, primarily the reaction of IPA in dinitrogen at short time scales to produce methane, HCN, acetone and "cold" CO at ca. 115 K. The CO, methane, and HCN rapidly established steady state concentrations, pointing to the need for faster FTIR studies: at longer times, isophorone and a "polymethylacetylene-like" polymer were formed as a brown oil. The observation of the steady-state gases and brown oil suggested parallel pathways in the plasma, the latter taking place at the plasma/catalyst interface, and the former in the plasma remote from the catalyst. Replacing dinitrogen with argon completely inhibited or negated the production of the oil, had no effect upon the processes taking place in the plasma remote from the Macor, and instead resulted in the production of acetylene.

Synthesis and characterization of V-doped TiO2 nanoparticles through polyol method with enhanced photocatalytic activities

This work reports the synthesis of vanadium-doped titanuim dioxide nanoparticles using titanium chloride and ethylene glycol as precursor and solvent respectively. The properties of as-prepared samples were investigated by X-ray diffractometry, scaning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, diffuse reflectance, and thermal analysis. X-ray diffraction patterns indicate that the TiO2 nanoparticles obtained after calcination at 500 °C under air atmosphere has the anatase phase with a tetragonal structure and the crystallite sizes were in the range 16.83–12.27 nm. The transmission electron microscopy was used to detect the morphology of synthesized nanoparticles. The functional groups present in the samples were identified by FTIR study. From the optical studies, there is a blue shift in the absorption edge for our samples that can be attributed to the presence of V in the TiO2. For V doped TiO2 nanoparticles the optical band gap varies between 3.18 and 2.60 eV with the increase of V concentration. The TGA findings allow the thermal cycle determination of samples whereas DTA findings allow the phase transition temperature identification. Finally, the evaluation of the photocatalytic activity is carried out using methyl blue as model of chemical pollutants in UV irradiation conditions and followed satisfactory the pseudo first order according to the Langmuir–Hinshelwood model.

A rotational Raman study under non-thermal conditions in a pulsed CO2 glow discharge

The implementation of in situ rotational Raman spectroscopy is realized for a pulsed glow discharge in CO2 in the mbar range and is used to study the rotational temperature and molecular number densities of CO2, CO, and O2. The polarizability anisotropy of these molecules is required for extracting number densities from the recorded spectra and is determined for incident photons of 532 nm. The spatiotemporally-resolved measurements are performed in the same reactor and at equal discharge conditions (5–10 ms on–off cycle, 50 mA plasma current, 6.7 mbar pressure) as in recently published work employing in situ Fourier transform infrared (FTIR) spectroscopy. The rotational temperature ranges from 394 to 809 K from start to end of the discharge pulse and is constant over the length of the reactor. The discharge is demonstrated to be spatially uniform in gas composition, with a CO2 conversion factor of 0.15 ± 0.02. Rotational temperatures and molecular composition agree well with the FTIR results, while the spatial uniformity confirms the assumption made for the FTIR analysis of a homogeneous medium over the line-of-sight of absorption. Furthermore, the rotational Raman spectra of CO2 are related to vibrational temperatures through the vibrationally averaged nuclear spin degeneracy, which is expressed in the intensity ratio between even and odd numbered Raman peaks. The elevation of the odd averaged degeneracy above thermal conditions agrees well with the elevation of vibrational temperatures of CO2, acquired in the FTIR study.

Multicomponent cyclodextrin system for improvement of solubility and dissolution rate of poorly water soluble drug

The purpose of the present study was to investigate the interaction of Cinnarizine (CIN) with Hydroxypropyl-β-Cyclodextrin (HPβCD) in the presence of Hydroxy Acids (HA). Various binary and ternary systems of CIN with HPβCD and HA were prepared by kneading and coevaporation methods. For the ternary systems, HA were tried in three different concentrations. The interaction in solution phase was studied in detail by the phase solubility method, and the solid phase interactions were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and Proton Nuclear Magnetic Resonance (1H-NMR). Phase solubility revealed the positive effect of HA on the complexation of CIN with HPβCD. Solid phase characterization confirmed the formation of inclusion complex in the ternary systems. Solubility and dissolution studies illustrated that out of three different concentrations tried, HA were most effective at the 1 M concentration level. Ternary systems were very effective in improving the solubility as well as dissolution profile of CIN than the CIN–HPβCD binary systems. FTIR, 1H-NMR and Molecular docking studies gave some insight at molecular level that actually which part of CIN was interacting with the HPβCD. Molecular docking and free energy calculation even enlighten the role of tartaric acid in increasing solubility of CIN in the ternary system.