ATR-FTIR Studies Research Articles

Genotoxic, biochemical, cytotoxic and biomolecular alterations in the early-life stage of zebrafish exposed to diphenyl ether

Diphenyl ether (DE) is a chemical compound being used in a number of industries such as soap, detergents, perfumes, adhesive, dyes, herbicides and as a flame retardant in plastics, rubbers and textiles, etc. DE is the final debromination product of polybrominated diphenyl ethers (PBDEs) under anaerobic conditions. The present investigation evaluated the genotoxic, biochemical, histopathological, ultrastructural (SEM) and biomolecular (ATR-FTIR) changes in the zebrafish larvae after DE exposure. After the determination of 96 h LC50 value zebrafish embryos were exposed to sublethal concentrations (¼ LC50 and ½ LC50) of DE. Significantly increased DNA damage in terms of tail length (TL), tail intensity (TI), olive tail moment (OTM) and tail moment (TM) was observed after the DE exposure to zebrafish larvae. Also, increased lipid peroxidation (MDA) and decreased FRAP activity were reported after DE exposure. The catalase (CAT), Glutathione-S-transferase (GST), and Acetylcholinesterase (AChE) activity were reported to be significantly increased and a decreased superoxide dismutase (SOD) activity was observed in DE-exposed groups. After DE exposure, Decreased cell viability and increased apoptosis were reported in zebrafish larvae. The histological and ultrastructural (SEM) analysis revealed the alterations in the zebrafish larvae exposed to DE. The ATR-FTIR study revealed the changes in the biomolecules such as DNA and protein after the DE exposure. The present study will help to understand the destructive aspects of DE in the early life stages of aquatic organisms and could be utilized to assess environmental risk.

Assessment of microplastics in highland rock salts of Northern Borneo

Mountain salts produced from the highland region in NE Sarawak have a market value and also provide basic income to the communities. During the salt-making process, microplastics (MPs) may enter into commercial table salts from various sources, which has not been explored yet. Hence, the current research investigates the presence of MPs in the rock salts produced from the highland saline water in two different locations (L1 and L2) in NE Sarawak. Among the brine water and rock salt samples analysed, the highest concentrations of MPs were detected from the salt samples. It has been revealed that both the water and salt samples have the highest concentration of MPs occurring within the size range of 1–1000 μm. Transparent MPs are the most common colour observed in both salt and water samples, followed by white, blue, red, and black. The most prevalent shapes of MPs are fibers, which account for almost 47% in water samples and 87% in salt samples. Based on the ATR-FTIR study, polyethylene (PE) is the most prevalent polymer observed in salt samples, followed by polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET). In water samples, PP is the most dominating polymer, followed by PE and PS. Through SEM microphotographs, fiber-type MPs have smooth surfaces, fragment-type MPs have rough edges, and sheet-type MPs have layered surfaces. EDX analysis revealed that carbon (C) and oxygen (O) are the most abundant elements, followed by aluminium (Al) and sodium (Na) in MPs. Based on the results, it is inferred that the MPs in the rock salts are mainly sourced from the different stages of salt-making production. This preliminary study shed light on the presence and characteristics of MPs in rock salts in this region. The research outcomes could support sustainable management plans to improve the salt quality and enhance the market value.

Enhancement of Solubility and Dissolution Rate of Simvastatin Tablets by Liquisolid Compact Approach

The aim of the current work was to improve the solubility and dissolution rate of poorly water-soluble drug, simvastatin (SM) by using the liquisolid compact technique (LS; SM-LS). Liquid load factors, and excipient ratios were used to calculate the required amounts of excipients necessary to prepare the SM-LS and compressed to tablets according to mathematical models. Avicel PH102, Aerosil 200 and Crosspovidone (CP) was used as carrier, coating material and disintegrant, respectively. Drug-excipient mixtures were evaluated compatibility by Attenuated total reflectance (ATR) and differential scanning calorimetry (DSC). Prepared SM-LS formulations were evaluated for various pre-compression and post-compressional parameters, in-vitro dissolution, and stability studies (40 ± 2°C / 75 ± 5% RH) for 3 months. Among the different formulations, LS10 formulation which contains 30% drug, 5% CP, Avicel pH 102: Aerosil 200 (1:10) showed 14-folds increase in dissolution rate when compared with pure SM powder. FTIR-ATR and DSC studies confirmed that there was no interaction between the drug and excipients. Further, the LS10 formulation had shown comparable dissolution profile with commercially available tablet formulation. The LS10 formulation showed no significant changes in the physicochemical properties over 3 months during stability studies. Therefore, the SM loaded LS formulation could be considered as an alternative approach to enhance the solubility and dissolution for commercial formulations. Keywords: Liquisolids compacts, solubility, dissolution, carrier, coating material, stability.

Thermoluminescence and ATR-FTIR study of UVC-irradiated low-density polyethylene (LDPE) food packaging

This research aims to study the effects of ultraviolet C (UVC) radiation on low-density polyethylene (LDPE) food packaging. Main objectives include evaluating LDPE degradation and detecting UVC radiation using thermoluminescent dosimeters (TLDs) placed under LDPE samples. Results confirm accurate UVC detection after one hour of exposure, providing a useful tool for optimize food treatment procedures.ATR-FTIR spectroscopy analysis revealed subtle alterations (<8 % transmittance relative) in UVC-irradiated LDPE samples, including possible CH breakage (2910 and 2848 cm−1) and potential CC bond vibrations (1470 cm−1), among others. However, observed variations may stem from LDPE properties rather than entirely from UVC radiation. A comparative study of UVC-induced thermoluminescence (TL) emissions provided insights into various TLDs materials. TL kinetic analysis, using computerised glow curve deconvolution (CGCD) method, unveiled trap charge activation due to UVC exposure, including partial ionization, bleaching effect and photo-transfer (PTTL) processes. LDPE samples amplified UVC-TL responses, revealing intensity differences between the TLDs attributed to the PTTL process, accentuated by the lack of an annealing treatment. Additionally, chemical composition of the TL detectors such as, type, concentration, number, oxidation states and ionic radii of their dopants may influence UVC-TL response. Consequently, TL intensity ratios follow as: GR-200 (LiF: Mg, Cu, P) > TLD-100 (LiF: Ti, Mg) > TLD-400 (CaF2: Mn) > TLD-200 (CaF2: Dy). Thus, GR-200 detects ionizing radiation but cannot distinguish between ionizing and non-ionizing UVC radiation, while TLD-100 has limited effectiveness as a UVC radiation detector. In contrast, TLD-400 is suitable for detecting UVC radiation and TLD-200 emerges as the most favorable UVC detector, showing consistent response levels and minimal PTTL effect placed under the LDPE samples without the need of a thermal annealing treatment that makes the TLD-200 to be reusable in a low-cost measurement protocol.

Synthesis, characterization, and biomedical potential of nickel oxide and Silver-doped nickel oxide nanoparticles via green synthesis method

The present study focuses on the synthesis of pure and different concentrations, viz. 2 %, 5 %, and 10 %, 15 % of Silver doped nickel oxide (NiO) nanoparticles prepared by green synthesis method using aqueous flower extract of Moringa oleifera Lam. (MO). The flower extract of MO contains several bioactive constituents that can be used as a strong reducing, stabilizing and capping agent to prepare pure and Silver (Ag) doped NiO NPs. The XRD studies confirm the crystallinity structure of the material. Pure NiO is found to be around 20.38 nm on average, 14.7–18.29 nm for Ag-doped NiO nanoparticles, and it belongs to the face-centred cubic (FCC) structure. The morphology of the samples is studied using SEM analysis, and the elements present are confirmed by EDS. FTIR-ATR studies confirm the structure of the functional groups present in the samples. The UV–Vis spectra analyses are used to calculate the band gap values for the synthesized nanoparticles. Agar well diffusion methods are used to study the antimicrobial activity of green synthesized pure and silver-doped NiO nanoparticles. The antimicrobial studies reveal that good antibacterial activity is present in both gram-positive and gram-negative organisms of the green synthesis of pure and Silver doped NiO nanoparticles. Hence, the synthesized silver-doped NiO nanoparticles can be used for biomedical applications due to their antibacterial properties.

Pickering emulsion stabilized by quercetin-β-cyclodextrin-diglyceride particles: Effect of diglyceride content on interfacial behavior and emulsifying property of complex particles

This research develops diacylglycerol (DAG) based Pickering emulsions with enhanced oxidative stability stabilized by self-assembled quercetin/DAG/β-cyclodextrin (β-CD) complexes (QDCCs) using a one-step agitation method. Influence of DAG content (5%, 15%, 40%, and 80%, w/w) on the self-assembly behavior, interfacial properties, and emulsifying ability of complex particles was investigated. SEM, XRD and ATR-FTIR studies confirmed the formation of ternary composite particles. QDCCs in 80% DAG oil had the highest quercetin encapsulation efficiency (6.09 ± 0.01%), highest DPPH radical scavenging rate and ferric reducing antioxidant property (FRAP). β-CD and quercetin adsorption rates in emulsion with 80% DAG oil were 88.4 ± 2.53% and 98.34 ± 0.15%, respectively. Pickering emulsions with 80% DAG had the smallest droplet size (8.90 ± 1.87 μm) and excellent oxidation stability. This research develops a novel approach to regulate the physicochemical stability of DAG-based emulsions by anchoring natural antioxidants at the oil-water interface through a one-pot self-assembly method.

Nanoformulated herbal compounds: enhanced antibacterial efficacy of camphor and thymol-loaded nanogels

Herbal components are highly useful assets for the advancement of novel antibacterial drugs. Nanotechnology holds great promise as an approach to enhance the effectiveness and develop the composition of these substances. The study developed nanogels incorporating camphor, thymol, and a combination derived from the initial nanoemulsions with particle sizes of 103, 85, and 135 nm, respectively. The viscosity of nanogels and the successful loading of compounds in them were examined by viscometery and ATR-FTIR studies. The bactericidal properties of the nanogels were examined against four bacterial strains. The nanogel containing camphor and thymol at 1250 µg/mL concentration exhibited complete growth suppression against Pseudomonas aeruginosa and Staphylococcus aureus. The thymol nanogel at 1250 µg/mL and the camphor nanogel at 2500 µg/mL exhibited complete inhibition of growth on Listeria monocytogenes and Escherichia coli, respectively. Both nanogels showed favorable effectiveness as antibacterial agents and could potentially examine a wide range of pathogens and in vivo studies.

Biting into the truth: Connecting oral pathology and stable isotopes through the paradigmatic example of a hyper-specialized marine diet in Medieval Pontevedra (NW Iberia)

Human feeding patterns have been reconstructed in Archaeology by analysing either oral pathology or stable isotope ratios in human skeletal remains. However, no clear agreement has been developed between these two methodologies. The main objective of this study is to determine if we can establish a link between them when analysing a population with a hyper-specialized diet, in this case marine resources (and millet/maize). To reach this goal we developed a conjoined multi-isotope analysis using collagen and bioapatite (δ13Ccol, δ15Ncol and δ13Ccar) and a detailed study of oral health (caries, antemortem loss, periapical lesions, periodontal disease, calculus, and wear). All available skeletons with at least one preserved tooth from two cemeteries of the medieval town of Pontevedra (n = 34) were studied. The buried individuals belonged to the guild of fishers and artisans, professions which were dominant among the families of medieval Pontevedra. A detailed FTIR-ATR study of extracted bone bioapatite showed a high correlation between bioapatite carbonate content, carbonate typical vibrations, and FTIR-ATR indices related to bone diagenesis, which is in line with previous research. No significant correlations were found with bioapatite yield and isotopic composition (δ13Ccar and Δ13C), ruling out possible diagenetic effects. The diet was based on marine fish protein with contributions of millets (e.g., δ13Ccar -11.9 ± 1.8‰) that seems to be slightly higher in individuals linked to artisanal guilds. The oral pathology study shows severe dental wear from an early age (Grade 2–4 in permanent dentition for 20% of infants and 60% of juveniles in M1), as well as moderate-high presence of caries in permanent dentition (64%, 22/34) and dental calculus (72%, 24/33). Both the oral pathology and the isotopic signal differ from that observed in other areas of the Iberian Peninsula. This study points to the existence of connections between findings of the two methodologies, and specifically an association between intense dental wear and high consumption of marine resources and millet. At the same time, this analysis implies the necessity of caution in estimation of age by dental wear in populations linked to the sea.

"Nano in Nano"-Incorporation of ZnO Nanoparticles into Cellulose Acetate-Poly(Ethylene Oxide) Composite Nanofibers Using Solution Blow Spinning.

In this work, the preparation and characterization of composites from cellulose acetate (CA)-poly(ethylene oxide) (PEO) nanofibers (NFs) with incorporated zinc oxide nanoparticles (ZnO-NPs) using solution blow spinning (SBS) is reported. CA-PEO nanofibers were produced by spinning solution that contained a higher CA-to-PEO ratio and lower (equal) CA-to-PEO ratio. Nanoparticles were added to comprise 2.5% and 5% of the solution, calculated on the weight of the polymers. To have better control of the SBS processing conditions, characterization of the spinning suspensions is carried out, which reveals a decrease in viscosity (two- to eightfold) upon the addition of NPs. It is observed that this variation of viscosity does not significantly affect the mean diameters of nanofibers, but does affect the mode of the nanofibers' size distribution, whereby lower viscosity provides thinner fibers. FESEM-EDS confirms ZnO NP encapsulation into nanofibers, specifically into the CA component based on UV-vis studies, since the release of ZnO is not detected for up to 5 days in deionized water, despite the significant swelling of the material and accompanied dissolution of water-soluble PEO. Upon the dissolution of CA nanofibers into acetone, immediate release of ZnO is detected, both visually and by spectrometer. ATR-FTIR studies reveal interaction of ZnO with the CA component of composite nanofibers. As ZnO nanoparticles are known for their bioactivity, it can be concluded that these CA-PEO-ZnO composites are good candidates to be used in filtration membranes, with no loss of incorporated ZnO NPs or their release into an environment.

ATR-FTIR Spectroscopic Analysis of Novel Fixatives and their Histological Properties On Sheep Heart

Objective: In this study, new fixative solutions that are odorless and non-toxic were tested on the hearts of sheep to preserve the cellular structure and tissue architecture in a life-like manner. Material and Method: The changes of new fixatives before and after contact with tissue were detected for the first time by the ATR-FTIR spectroscopic method. After a preliminary inspection, hearts were fixed with six different solutions. It was periodically evaluated for weight, size, color, and hardness. Samples taken from the left vertical of each heart and stained with Hematoxylin eosin were observed histologically and alterations at the cellular level were evaluated. Results: As a result of the measurements of heart weights, reduction in Solution 1 (Standard Formaldehyde Fixative), Solution 4 and Solution 5 were detected at 5.64%, 23.70% and 14.38%, respectively. In Solution 4 and Solution 5, it was observed that the integrity of the myocardium was protected in terms of morphology, the stiffness was suited for sectioning and the coronary vessels were well preserved according to Solution 1. Further, compared to solution 1, it was determined that the endocardium and myocardium layers were well preserved in the tissues fixed in Solution 4 and Solution 5. Typical transversal streaking appearance in cardiac muscle tissue existed in all three Solution 1, Solution 4 and Solution 5. Conclusion: Solution 4 and Solution 5 were found to have superior fixative properties than Solution 1 (Formaldehyde). As a result of ATR-FTIR studies, it was determined that formaldehyde was converted into toxic formic acid in Standard Solution 1, while very few and harmless changes were detected in Solution 4 and Solution 5.

Enhanced adsorption of phenol using graphene oxide-bentonite nanocomposites: Synthesis, characterisation, and optimisation

Wastewater treatment is crucial because it causes harm to the environment of human beings. Adsorbents are faulted by low adsorption capacity and difficult recovery due to organic pollutants. This study aims to improve adsorption capacities using bentonite and other environmentally friendly and economically feasible adsorbents. To do this, using Hammer's approach, bentonite was subjected to an acidic treatment (1.5 M H2SO4) and then hybridized with synthetic graphene oxide (GO). Integrating GO nanosheets within the interlayer of acid-activated bentonite and depositing them onto the exterior surface using a simple ultrasonic-assisted method successfully created a graphene oxide-bentonite nanocomposite. GO, and its composites (at 5 and 10 wt%) were characterized using ATR-FTIR, BET, XRD, FE-SEM, and AFM studies. The results demonstrated that GO with a single-layer thickness of 0.618 nm could be successfully fabricated. We employed energy-dispersive X-ray spectroscopy (EDX) to detect changes in chemical composition before and after phenol adsorption. It was thoroughly studied how essential factors, including adsorbent dosage, pH, agitation period, and beginning phenol concentration, affected adsorption behavior. An obvious increases of the adsorption capacities from 30.69 to 46.43 mg/g were achieved under ideal circumstances of pH 6, an 8-hour contact duration, and doses of 0.3 g and 0.2 g for GO-MB5 and GO-MB10 composites, respectively. The pseudo-second-order kinetic and Langmuir equilibrium isotherm models efficiently described the adsorption process. More notably, the synthesized adsorbents could be successfully regenerated and used without major capacity losses after six cycles. This study highlights the effectiveness of GO-bentonite nanocomposites as effective adsorbents for environmental treatment.

Thermoelectric Properties of Flexible Polyvinyl Alcohol/Poly (3,4- Ethylenedioxy thiophene)/Titanium Carbide Ternary Composites

The thermoelectric (TE) characteristics of polyvinyl alcohol/poly (3,4-ethylenedioxy thiophene)/titanium carbide (PVA/PEDOT/TiC) composites were explored in this work. The composite films with varying TiC weight ratios were made using the solvent casting process. The homogeneous distribution of TiC particles in the composite structure was revealed by SEM micrographs. The presence of TiC particles in the crystallinity of PVA/PEDOT was revealed by XRD patterns. The electrostatic interactions in the composite structure were revealed by FTIR-ATR studies. The electrical conductivity of PVA/PEDOT rose from 0.06 S/cm to 1.15 S/cm with the contribution of 5% TiC, while the Seebeck coefficient increased from 3.9 µV/K to 98.8 µV/K with the contribution of 1% TiC, according to TE studies. The composite samples exhibited a maximum power factor of 0.72 µW/mK2 , which is 104 times greater compared to PVA/PEDOT.

Wetting and swelling behaviour of N-acetylated thin chitosan coatings in aqueous media

Chitosan nanocoatings (thickness range of 120–540 nm) were produced on glass, zinc and silicon substrates with dip-coating and spin coating techniques to study their pH-dependent wetting and swelling behaviour. The coatings were N-acetylated with the methanolic solution of acetic anhydride to increase the degree of acetylation from 36 % to 100 % (according to ATR-FTIR studies). The measured contact angles of Britton–Robinson (BR) buffer solutions (pH 6.0, 7.4 and 9.0) were lower on the acetylated surfaces (ca. 50°), than that of their native counterparts (ca. 70°) and does not depend on the pH. Contrary, contact angles on the native coating deteriorated 10°-15° with increasing the pH. In addition, for native coatings, the decrease of the contact angles over time also showed a pH dependence: at pH 9.0 the contact angle decreased by 7° in 10 min, while at pH 6.0 it decreased by 13° and at a much faster rate. The constraint swelling of the coatings in BR puffer solutions was studied in situ by scanning angle reflectometry. The swelling degree of the native coatings increased significantly with decreasing pH (from 250 % to 500 %) due to the increased number of protonated amino groups, while the swelling degree of acetylated coatings was ca. 160 % regardless of the pH. The barrier properties of the coatings were studied by electrochemical tests on zinc substrates. The analysis of polarization curves showed the more permeable character of the acetylated coatings despite the non-polar character of the bulk coating matrix. It can be concluded that in the case of native coatings, 49 % of the absorbed water is in bound form, which does not assist ion transport, while in the case of acetylated coatings, this value is only 33 %.

Polymer Gel Substrate: Synthesis and Application in the Intensive Light Artificial Culture of Agricultural Plants.

This work is devoted to the description of the synthesis of hydrogels in the process of cryotropic gel formation based on copolymerization of synthesized potassium 3-sulfopropyl methacrylate and 2-hydroxyethyl methacrylate (SPMA-co-HEMA) and assessing the potential possibility of their use as substrates for growing plants in intensive light culture in a greenhouse. Gel substrates based on the SPMA-co-HEMA were created in two compositions, differing from each other in the presence of macro- and microelements, and their effects were studied on the plants' physiological state (content of chlorophylls a and b, activity of catalase and peroxidase enzymes, intensity of lipid peroxidation, elemental compositions) at the vegetative period of their development and on the plants' growth, productivity and quality of plant production at the final stages of development. Experiments were carried out under controlled microclimate conditions. Modern and standard generally accepted methods of gels were employed (ATR-FTIR and 13C NMR spectral studies, scanning electron microscopy, measurement of specific surface area and pore volume), as well as the methods of the physiological and chemical analysis of plants. The study demonstrated the swelling ability of the created gel substrates. Hydrogels' structure, their specific surface area, porosity, and pore volume were investigated. Using the example of representatives of leaf, fruit and root vegetable crops, the high biological activity of gel substrates was revealed throughout the vegetation period. Species specificity in the reaction of plants to the presence of gel substrates in the root-inhabited environment was revealed. Lettuce, tomato and cucumber plants were more responsive to the effect of the gel substrate, and radish plants were less responsive. At the same time, more pronounced positive changes in plant growth, quality and productivity were observed in cucumber and lettuce in the variant of gel substrates with macro- and microelements and in tomato plants in both variants of gel substrates. Further research into the mechanisms of the influence of gel substrates on plants, as well as the synthesis of new gel substrates with more pronounced properties to sorb and retain moisture is promising.

Evaluation of haematological, genotoxic, cytotoxic and ATR-FTIR alterations in blood cells of fish Channa punctatus after acute exposure of aniline

Aniline (C6H5NH2) an important intermediate in the organic and fine chemical industry, is ubiquitously used worldwide. It is one of the important building block for manufacturing of 4,4-methylene diphenyl diisocyanate (MDI), accelerators in rubber processing, dyes, tattoo inks, photographic chemicals, antioxidants, corrosion inhibitors, pharmaceuticals and antiseptics. The current study evaluated 96 h LC50 of aniline and based on this, two sublethal concentrations (4.19 mg/l and 8.39 mg/l) were selected for acute exposure studies in freshwater food fish Channa punctatus. Erythrocytes of fish are nucleated hence they play an important role in physiology, immune system, protein signalling and haemostatic condition along with respiration. Blood samples were collected after 24, 48, 72, and 96 h of exposure to study haematological, cytotoxic and genotoxic effects of sublethal concentrations of aniline in C. punctatus. Symbolic elevation in time and dose dependent DNA damage was observed by comet assay as well as micronuclei assay revealing maximum damage after 96 h of exposure. After aniline exposure, scanning electron microscopy and ATR-FTIR studies showed anomalies in structure and alterations in biomolecules of RBCs of aniline exposed group as compared to control group respectively. Semi prep HPLC studies revealed bioaccumulation potential of aniline in higher concentration exposed group.

Novel role of folate (vitamin B9) released by fermenting bacteria under Human Intestine like environment

The anaerobic region of the gastrointestinal (GI) tract has been replicated in the anaerobic chamber of a microbial fuel cell (MFC). Electroactive biomolecules released by the facultative anaerobes (Providencia rettgeri) under anoxic conditions have been studied for their potential role for redox balance. MALDI study reveals the presence of vitamin B9 (folate), 6-methylpterin, para-aminobenzoic acid (PABA) and pteroic acid called pterin pool. ATR-FTIR studies further confirm the presence of the aromatic ring and side chains of folate, 6-methylpterin and PABA groups. The photoluminescence spectra of the pool exhibit the maximum emission at 420, 425, 440, and 445 nm when excited by 310, 325, 350, and 365 nm wavelengths (day 20 sample) highlighting the presence of tunable bands. The cyclic voltammetric studies indicate the active participation of pterin pool molecules in the transfer of electrons with redox potentials at − 0.2 V and − 0.4 V for p-aminobenzoate and pterin groups, respectively. In addition, it is observed that under prolonged conditions of continuous oxidative stress (> 20 days), quinonoid tetrahydrofolate is formed, leading to temporary storage of charge. The results of the present study may potentially be useful in designing effective therapeutic strategies for the management of various GI diseases by promoting or blocking folate receptors.

Dissolution Enhancement of Ketoconazole by Melt Granulation Co-Processing

Background: Melt granulation (MG) is a simple operation involving a uniform mixture of active ingredients with a melted polymeric carrier. However, this process can also enhance a drug's biopharmaceutical properties by augmenting its dissolution rate and, thus, its absorption. Purpose: By applying MG technology, current research focuses on developing co-processed ketoconazole with a higher aqueous dissolution rate than its pure form. Methods: A measure of how the type and proportion of polymeric carriers affect the crystallinity and dissolution rate of co-processed ketoconazole materials was performed. MG prepared materials in a high-shear mixer using co-povidone (Kollidon®) VA 64, HPMCAS HF as polymeric carriers, PEG 1450 (Kollisolv®) and triethyl citrate as plasticizers. Results: The co-processed ketoconazole materials exhibited miscibility in the polymeric systems, as indicated by the reduction in the enthalpy of fusion. Drug crystallinity was significantly reduced in the HPMCAS HF polymeric system, confirmed by XRPD and ATR-FTIR studies. The dissolution rate was enhanced by using a higher drug concentration in a co-povidone VA 64 environment; contrarily, for HPMCAS HF, a higher drug dilution was observed to favor the dissolution rate. Conclusions: MG is a handy, low-cost technology that develops dissolution-enhanced co-processed active pharmaceutical ingredients, spotting specific carrier-drug interactions. MG yields scalable, proven processes, raising interest in its applications in optimizing drug therapeutic efficacy. Ultimately, this technology for dissolution enhancement could bring lower-cost, high-efficiency drugs to improve patients' quality of life.

Nicotinamide-based agglomerates of ibuprofen: formulation, solid state characterization and evaluation of tableting performance with in-silico investigation

BackgroundThe objective of the present investigation was to obtain directly compressible agglomerates of ibuprofen with nicotinamide by a quasi-emulsification solvent diffusion technique. Ibuprofen-nicotinamide agglomerates were prepared by quasi-emulsification solvent diffusion technique using ethanol (good solvent), water (poor solvent), and chloroform (bridging liquid). The prepared agglomerates were characterized by ATR-FTIR, powder X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy and were evaluated for tableting performance and in vitro drug release. To appropriately identify the hydrogen bonding sites, a thorough understanding of the structures of API and coformer is necessary, hence molecular docking approach was implemented to depict the interaction between the proposed coformer and COX-2 protein (PDB Id:4PH9).ResultsThe percent yield of agglomerates was in the range of 85–98 w/w%, and drug content for all batches was in the range of 96–99%. The microphotographs showed irregular circularly shaped agglomerates. ATR-FTIR study showed a strong possibility of hydrogen bonding between ibuprofen and nicotinamide. The crystallinity of ibuprofen was slightly reduced and confirmed by P-XRD and DSC. Crushing strength and friability studies showed good handling qualities of ibuprofen agglomerates. Heckel plot studies showed low mean yield pressure and high tensile strength, indicating excellent compressibility and compactibility of ibuprofen agglomerates. More than 90% drug release was obtained within 60 min in PBS (pH 7.4). The docking studies revealed that nicotinamide individually has –CDOCKER energy 16.8109 where coformer showed 29.0584, which indicates coformer has a better binding affinity to target as compared to nicotinamide individual.ConclusionsIt can be concluded that the agglomerates improved the dissolution, tableting performance, and solid-state properties of ibuprofen and hence can be useful to improve the therapeutic performance of ibuprofen.Graphic

Fabrication of versatile Ag-P/Ppy core-shell nanocomposite: Adsorption efficacy for chromium (VI) removal and assessment of antioxidant and antibacterial activities

This study reports the synthesis, via in-situ chemical oxidative polymerisation, of conducting polymer-based silver phosphate Polypyrrole (Ag-P/Ppy) core-shell nanocomposite, exhibiting antioxidant and antibacterial characteristics, for the adsorption of chromium (VI) ions from aqueous solutions. Filtering away Cr (VI) ions efficiently also improves the filtered water with antibacterial and antioxidant properties. P-XRD, ATR-FTIR, FESEM, EDAX, TEM, zeta potential, TGA, and BET studies characterized Ag-P/Ppy. The core-shell nanostructure of Ag-P/Ppy was determined by TEM micrographs, which indicated the presence of an Ag-P core and a Ppy shell. pH value, adsorbent dose, stirring rate, contact time, and Cr (VI) pollutant concentration, were investigated as potential influencing factors. At pH 2, 99.4 % of Cr(VI) was removed in 55 min. The adsorption kinetics was effectively depicted by a pseudo-second-order kinetics model, signifying that chemisorption played a momentous role in the total adsorption capacity. Freundlich, Temkin, Redlich-Peterson, and Sips isotherm models were fitted to adsorption data. Temkin and Redlich-Peterson models have a higher (0.99) correlation coefficient than Freundlich (0.95) and Sips (0.98). The maximum adsorption capacity (qm) evaluated using the Sips model was 138.5 mg g−1, which was quite close to the 130.55 mg g−1 value obtained from experiments. The manufactured nanocomposite showed 91.2 % radical scavenging activity in a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Antibacterial activity of the Ag-p/Ppy core-shell nanocomposite contrary to gram-positive (S. aureus) and gram-negative (P. aeruginosa, E. coli, and K. pneumoniae) bacteria was assessed by means of the agar well diffusion technique. Compared to the positive control, it inhibited S. aureus, E. coli, K. Pneumoniae, and P. Aeruginosa by 82.35 %, 79.5 %, 63.63 %, and 76.7 % respectively. Therefore, the Ag-P/Ppy core-shell nanocomposite has the potential as a potent and versatile adsorbent for the exclusion of Cr (VI) ions from water.

Tailor-made starch-based adhesives chemically modified with NaOH:urea and their applications on a cellulosic substrate

Adhesives formulated with native starches have high viscosity, low solids content, poor bond strength and stability due to the starch retrogradation. To overcome this problem, a strategy is the starch treatment with NaOH solution combined with urea, capable of intercalating in the polymeric chains of starch. The aims of this work were to develop adhesives based on chemically modified cassava starch with different NaOH:urea ratios and to study in depth the effect induced by the addition of different concentrations of alkali and urea in the adhesive capacity of formulations that determine their subsequent application in paper-based packaging.Firmness and consistency of the adhesive increased for the 1:1 ratio while it decreased for the NaOH:urea 2:1 ratio, suggesting that the hydrolysis of polymer chains occurred. Additionally, adhesives prepared with 15 % starch maintaining NaOH:urea ratios of 0.5:1: and 1:1 exhibited the highest stress values. ATR-FTIR studies supported the results obtained.It was possible to obtain formulations with different adhesive properties with applications in paper-based packaging. From the analysis of the studied parameters, the combination of 15 % w/w cassava starch with a ratio of NaOH:urea 1:1 allows obtaining adhesives with adequate consistency and adhesive capacity which remain stable during the adhesive storage.