Halloysite-alginate beads loaded with mesalazine or 5-amino salicylic acid (5-ASA), a model anti-inflammatory drug, were investigated for their ability to protect the drug from acidic degradation during gastrointestinal transit. X-ray fluorescence (XRF) analysis confirmed the composition of the halloysite nanotubes, while zeta potential analysis corroborated their colloidal stability. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) investigations confirmed the effective production of the nanocomposite and provided insights into the interactions between its components and crystalline structure. The structure and homogeneous size distribution of the halloysite nanotubes (HNT) were examined using transmission electron microscopy (TEM). Additionally, scanning electron microscopy (SEM) images indicated a spherical shape and a relatively rough bead surface. Upon initial incubation in a simulated gastric medium (pH 1.2), the beads remained unchanged. In contrast, incubation in a simulated intestinal medium (pH 6.8) led to bead swelling, floating, and erosion. Furthermore, the formulation exhibited a smart, pH-sensitive release mechanism, achieving complete drug release over 750minutes, highlighting its potential for sustained and targeted drug delivery. Release data for 5-ASA were well-fitted to the Korsmeyer-Peppas and Higuchi models, indicating distinct mechanisms governing the release from the composite material. Density functional theory (DFT) analyses revealed specific interactions between 5-ASA and halloysite, characterized by strong hydrogen bonding and Lewis acid-base interactions with aluminol sites, alongside reduced van der Waals forces in the hydrophobic siloxane regions.

This study presents a novel composite beads, AC@Alg-PANI, consisting of activated carbon (AC) derived from Crataegus monogyna , sodium alginate (Alg), and polyaniline (PANI), tested for the removal of methylene blue (MB). The physicochemical characteristics of the composite beads were analyzed using methods such as pH PZC , FTIR, TGA/DTA, SEM, and BET. Moreover, factors affecting the adsorption of MB, such as initial pH, dye concentration, adsorbent weight, ionic strength, and temperature, were also explored. A full factorial design was implemented to identify the optimum conditions for removal, which were found to be a pH of 6, an adsorbent amount of 100 mg, and a dye concentration of 100 mg/L. The isotherm data indicated that the adsorption of MB by AC@Alg-PANI follows the Langmuir model, with a maximum adsorption capacity of 774.6 mg/g. The adsorption kinetics followed the pseudo-first-order model, indicating that the adsorption process is physical in nature. The thermodynamic results suggest that MB adsorption on AC@Alg-PANI was favorable, spontaneous, and endothermic. Additionally, after five regeneration cycles, the composite beads demonstrated excellent recyclability for MB dye removal with high efficiency. Furthermore, molecular dynamics simulations (MDS) of the adsorption energy highlighted the physically spontaneous nature of the process, involving various weak interactions, including van der Waals forces, intermolecular interactions, hydrogen bonding, and pi-electron interactions.

Chitosan/bentonite beads (CsB) composites were prepared from chitosan (Cs) and bentonite (B) and cross-linked with epichlorohydrin for removal of reactive orange 16 (RO16) and methylene blue (MB). The adsorption results have shown that the (Cs20B80), 20 % wt of (Cs) and 80 % (B), was selected as the best adsorbent for (MB) and (RO16) dyes. SEM, EDX, FTIR, BET, and pHpzc were implemented to investigate the features of Cs, B, and Cs20B80 samples. The influence of contact time (0-72 h), initial RO16 concentration (15-300 mg/L), temper-ature (30, 40, and 50 degrees C), the quantity of adsorbent (1-4 g/L), ion strength (0.1-1 M), and solution pH (3-10) on RO16 adsorption onto Cs20B80 were explored. The pseudo-second-order and the Langmuir models fit adequately the adsorption kinetic results and the isotherms ones respectively. Also, the maximal monolayer capacities calculated using the non-linear form of the Langmuir isotherm are 55.27, 55.29, and 70.80 mg/g, at 30, 40 and 50 degrees C. Based to the statistical physics model, the RO16 could be retained on the surface of Cs20B80 through a non-parallel orientation. The RO16 adsorption process is endothermic and natural, as demonstrated by ther-modynamic studies. After three regeneration cycles, the Cs20B80 composite has shown an adsorption capacity of around 20 % compared to the initial one. The adsorption energy of RO16 onto Cs, B, and Cs20B80 examined using the Monte Carlo simulation method (MC) ranged from-164.8 to-303.7 (kcal/mol), showing the potential of the three adsorbants for RO16 dye. Also, the process of adsorption of RO16 dye on the surface of Cs20B80 composite indicates several kinds of physical interactions, involving electrostatic interaction, hydrogen bonding, and 7C-7C interactions, this finding was proved theoretically via molecular dynamic simulations.

Preparation of microspheres containing Mesalazine referred to as 5-aminosalicylic acid (5-ASA) for colon targeting drug was carried out using the emulsion solvent evaporation technique. The formulation was based on 5ASA as the active agent, sodium Alginate (SA) andEthylcellulose (EC) as encapsulating agents, with polyvinyl alcohol (PVA) as emulsifier. The effects ofthe following processing parameters, 5-ASA %, EC:SA ratio and stirring rate on the properties of the resulting products in the form microspheres were considered. The samples were characterized using Optical microscopy, SEM, PXRD, FTIR, TGA, and DTG.In vitro release of 5-ASA from the different batches of microspheres was tested in biologically simulated fluids, (gastric; SGF, pH 1.2 for 2 h), then (intestinal fluid SIF, pH 7.4for 12 h) at 37 degrees C. The release kinetic results have been treated mathematically relaying on Higuchi's and Korsmeyer-Peppas' models for drug liberation. DOE study was performed to evaluate the interactive effects of variables on the drug entrapment and microparticle sizes. Molecular chemical interactions in structures were optimized using DFT analysis.

Carbon black (CB) has been used for over one-hundred years as a reinforcing filler in rubber matrix. In order to reduce our dependence on fossil resources, attempts have been made to develop renewable biofillers such as starch in the rubber industry. In this study, NR/SBR blends (50/50) were prepared with different loading of wheat starch (5, 10, 20, 35 and 50 phr). A semi-efficient sulphur vulcanization system (semi-EV) was employed. The curing characteristics of the compounds were determined with a Monsanto Rheometer at 130, 140 and 150 °C. The properties of unfilled and filled NR/SBR blends prepared at 150 °C were evaluated by swelling measurements, tensile tester, dynamic mechanical analyser (DMA) and scanning electron microscope (SEM). The results showed that the optimal cure time, minimum torque, and maximum torque of filled NR/SBR blends were improved. It was found that the tensile strength and the elongation at break of wheat starch filled NR/SBR blends were maximal with the incorporation of 20 phr of wheat starch. The chemical crosslink densities were found to follow the mechanical properties. The results of DMA indicated that incorporation of wheat starch led to an increase in the glass transition temperature whilst reducing the mobility of macromolecular chains of NR/SBR mixtures, and on the other hand improved their slip resistance on wet surfaces, thus indicating its potential application in the manufacture of tyre tread.

In the present work, elegant modification of halloysite (Hal) by citric acid (CA) was realized. The corresponding novel bio-composite (Hal-CA) was then used as drug carrier. To validate this concept, ketoprofen (KET), a known non-steroidal anti-inflammatory agent, was chosen as drug model. KET has low solubility and a short biological half-life, which can cause some limitations in its therapeutic use. In addition, its use is limited due to gastrointestinal side effects. All Hal, Hal-CA, Hal-KET and Hal-CA-KET samples were characterized using several techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), N2 adsorption-desorption, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The release of KET from the prepared formulations was investigated at pH 1 and 6.8 by means of UV-Visible spectroscopy. In addition, kinetics of the release of KET from inclusion complexes were determined by fitting the release profiles to the first order, Korsmeyer-Peppas and Higuchi models. In order to assess these novel bio-composites, anti-inflammatory and anti-nociceptive activities were also evaluated in vivo. Finally, the ulcerogenic activity and the histopathological effects of all formulations were compared to that of pure KET. This work showed the increase of the anti-inflammatory and antinociceptive potentials of KET loaded in Hal-CA, as well as a maximum protection against ulcers. This suggests that Hal-CA can be considered as a new carrier for pharmaceutical formulations.

In recent years, the application of halloysite (HAL) in the conception of drug systems has become important due to its excellent physicochemical properties. Ketoprofen (KET) is widely used around the world as an anti-inflammatory drug. A formulation of HAL-KET was prepared. The interaction between the KET molecules and HAL has been investigated experimentally by Zeta potential, TEM, XRD, FTIR spectroscopy and TGA/DSC. In addition, this interaction was studied theoretically by using Monte-Carlo calculation method (MC). The results have shown that the interaction of KET is stabilized not only by electrostatic interactions and hydrogen bonds with HAL but also via the delocalized π electrons density of phenyl groups of KET and the hydrogen atoms of HAL.

The aim of this study was to prepare and characterise inclusion complexes of a low water-soluble drug, mefenamic acid (MA), with β-cyclodextrin (β-CD). First, the phase solubility diagram of MA in β-CD was drawn from 0 to 21 × 10-3 M of β-CD concentration. A job's plot experiment was used to determine the stoichiometry of the MA:β-CD complex (2:1). The stability of this complex was confirmed by molecular modelling simulation. Three methods, namely solvent co-evaporation (CE), kneading (KN), and physical mixture (PM), were used to prepare the (2:1) MA:β-CD complexes. All complexes were fully characterised. The drug dissolution tests were established in simulated liquid gastric and the MA water solubility at pH 1.2 from complexes was significantly improved. The mechanism of MA released from the β-CD complexes was illustrated through a mathematical treatment. Finally, two in vitro experiments confirmed the interest to use a (2:1) MA:β-CD complex.

Many obstacles associated with the use of conventional drug delivery systems have led to the development of new various micro/nano sized drug carriers, such as microcapsules and nanoparticles. These carriers are designed with the aim to improve therapeutic outcomes and/or reduce drug’s adverse effects, by providing protection of the entrapped drug against in vivo degradation, releasing drug in desired man­ner, improving drug solubility and/or reducing its immunogenicity. Additionally, their small sizes make these carriers when loaded with the bioactive molecules suitable for different routes of administration allowing their vectorization to the target site. In this work, Diatomite (DTM) was used as a support material for Itraconazole (ITZ) which is known for its fairly low side effects. The major drawback in the therapeutic application and efficacy of ITZ as oral dosage forms is its very low aqueous solubility which is related to its hydrophobic structure. Three Binary systems were prepared using different proportions of the two components and where tested for the ability of DTM material to improve the solubility of ITZ in aqueous solvents and in organic media. The efficacy of encapsulation was demonstrated by standard methods such as extraction and UV analysis. The prepared systems were characterized using UV-Vis, FTIR, MEB, AFM and Optical microscopy. Moreover, the study of kinetics and mechanism of drug release in the gastric medium exhibit a sustained profile during a time of two hours.

The aim of this work is to investigate the solubility enhancement of mefenamic acid (MA), a non-steroidal anti-inflammatory agent, by formation of stable amorphous ternary system (MA, polyvinylpyrrolidone (PVP), β-cyclodextrin (β-CD)) compared to the binary system (MA, β-CD). Firstly, on the basis of the molecular docking simulation and job’s plot results, three methods were adopted for the preparation of the binary inclusion complexes at the ratio of 2:1 of MA:β-CD, namely solvent co-evaporation (CE), kneading (KN) and physical mixture (PM). However, in order to decrease tendency to self-assembly of cyclodextrins and form aggregates in aqueous media, each binary system was co-milled at ambient temperature in presence of different ratios of a highly water-soluble polymer (PVP). These complexes were characterized using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), nuclear magnetic resonance (1H- and 13C-NMR) spectroscopy and scanning electron microscopy (SEM) techniques. The release of the drug from the diverse formulations was also investigated by means of UV-VIS spectroscopy. Finally anti-inflammatory and anti-nociceptive activities were performed. The results showed that the solubility of MA in water from ternary complexes was significantly improved.

The aim of this work is the enhancement of the hydrosolubility behaviour of a poorly soluble, weakly basic drug, using itraconazole (ITZ) as a case example. Binary inclusion complexes of ITZ with β-cyclodextrin (β-CD) are prepared in 1:2 molar ratios of ITZ to β-CD by co-evaporation method. Both solubility and dissolution behaviour are compared with that of the pure drug. Ternary complexes can be obtained by adding the polyvinylpirrolidone (PVP) which is a highly water soluble polymer, in the ITZ/ β-CD complex formation. Actually, Solid state analysis is performed for all formulations and for pure ITZ applying the Fourier transforms infrared (FT-IR) spectroscopy, powder X-ray diffraction (pX-RD) and differential scanning calorimetry (DSC). Solubility tests indicate that with all formulation, the solubility of ITZ formed with β-CD or β-CD and PVP proved to be increased. The obtained results show that the pure drug has a poor dissolution property, and the ternary inclusion complexes resulted in fast and extensive release of ITZ. Keywords: Itraconazole, β-cyclodextrin, polyvinylpyrrolidone.

Nigella sativa seeds waste (NSW) was characterized by Fourier transformed infrared spectroscopy, X-ray diffraction, thermogravimetric analysis-TDA, and scanning electron microscopy analysis and used for the adsorptive uptake of methylene blue (MB) from water. The specific surface area of NSW determined by the methylene blue adsorption method was equal to 465.95 m(2)/g. The experimental equilibrium data were investigated using the isotherm equations of Langmuir, Freundlich, Temkin, Redlich-Peterson, Sips, and Radke-Prausnitz. The models of pseudo-first-order, pseudosecond-order, Elovich, intraparticle diffusion, and Avrami were applied for the kinetic data modeling. The maximum MB adsorption capacity of NSW obtained by the Langmuir equation was 149.4 mg/g. The experimental kinetic data fitted very well to the Avrami model. Thermodynamic parameters indicate the spontaneous and endothermic nature of MB adsorption onto NSW. The statistical physics model with single energy was used to determine the adsorption mechanism of MB on NSW. The model confirms the endothermic and physical nature of the process with an anchorage of MB onto NSW. The receptor site density (N-M), the adsorbed dye quantity at saturation (N-sat), the concentration at half-saturation (C-1/2) and the adsorption energy (Delta E) values are equal to 128.23, 141.1 mg/g, 25.4 mg/L and 18.0 kJ/mol, respectively.

Microparticles charged by niflumic acid and based on cellulose derivatives as polymeric matrices, that is, ethylcellulose (EC) and mixtures of EC and hydroxypropylmethylcellulose (HPMC), were elaborated using microencapsulation by emulsion-solvent evaporation technique. The niflumic acid is considered as a poorly water soluble drug, so the main objective of the paper is to use designs of experiment in order to prepare new solid formulations with a large range of size for the drug dissolution enhancement. The possible drug-polymer interaction was investigated by Fourier transform-infrared spectroscopy, X-ray diffraction, and differential scanning calorimetric analysis. Some of the process variables, namely, the stirring speed of emulsion, the emulsifier concentration, and the EC:HPMC ratio, were selected and varied. Their main and interactive effects on the microparticles' characteristics were obviously evaluated and discussed using Minitab software 16.1. The obtained microparticles' size (d(10)) ranged from 196 to 796 mu m, and the drug entrapment reached 45% in some formulations. The drug dissolution results showed that the Higuchi's release constant varied from 0.011 to 0.067 min(-1/2) and was enhanced especially when the HPMC concentration was increased.

Blends of polypropylene (PP) and high-density polyethylene (HDPE) were prepared by reactive blending in the presence of dicumyl peroxide (DCP) as a free radical generator, maleic anhydride (MAH) as a cross-linking agent and organo-montmorillonite (O-Mt) as filler. Titanium dioxide (TiO2) was added as a anti UV agent known as well for its antimicrobial activity. This formulation was aimed to see how an incompatible blend will behave in the presence of the above cited ingredients and if it will have an anti-bacterial activity. The compounding of the ingredients was carried out in internal brabender mixer. The resulting materials were characterized using different techniques: dynamical rheological analysis (DRA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and mechanical testing. The results showed that the presence of titanium dioxide in the blends PP/HDPE leads to the destruction of the octahedral and tetrahedral structure of the clay (exfoliation form), results confirmed by FTIR analysis where it has been observed that the peaks associated with the octahedral structure have disappeared. AFM showed a smooth surface for the materials mainly those with high relatively organo-montmorillonite content and TiO2 which showed improvement in their mechanical properties. Antibacterial efficiency of the composites depends on the dispersion and the concentration of the TiO2 particles and it was concluded that composites with either low or high content of TiO2 showed antibacterial property.

Abstract We report an investigation on the effect of iron and cobalt stearates as pro-degradants and their synergetic effect on the oxidation and subsequently the biodegradation behavior of low density polyethylene (LDPE) film. For this, LDPE films containing different amounts of these additives were prepared and characterized upon exposure to accelerated thermal and photo-oxidation. The analysis shows that the films underwent a significant degradation as monitored by carbonyl index, changes in the crystallinity, in the onset of decomposition temperature and hydrophobicity. The tendency to biodegradation of the oxidized LDPE, with and without pro-oxidant/pro-degradant, was then assessed through the soil burial and the aqueous medium techniques. After an incubation period of 120 days, samples were characterized by means of structural changes and cumulative CO2 emissions. During the incubation in both soil and aqueous medium, the fragmented films with pro-oxidant/pro-degradant showed a significant decrease in oxygenated moieties present initially in the polymer and formed during the accelerated ageing when compared with LDPE without pro-oxidant/pro-degradant, and the biodegradation in the different environment was highly effective following the order LDPE/Co>LDPE/Co/Fe>LDPE/Fe>LDPE and in the range of 13–45% of mineralization after 120 days in aqueous medium and 13–29% in solid medium. These results suggest the role of pro-oxidant/pro-degradant and specially their mixture and the natural environment in oxidation and degradation of LDPE samples and in the mineralization process of oxidized fragments.

This study treats one important aspect of starch-filled rubber compounds which is their rheological behavior. Starch-based SBR1712 masterbatches resulting from various formulations were prepared using a mini two roll mill and an internal mixer (Plastograph Brabender).The content in starch was varied from 0 to 50 phr. The effect of starch content on the rheological behavior was evaluated through the flow characteristics in the temperature range (130-160 °C) which matches that used in the vulcanization process. Four experimental techniques were considered to assess the mixing and the flow behavior of the materials: 1) Brabender mixer, 2) melt flow index, 3) capillary rheometer and finally 4) dynamic rheological properties through strain sweep experiments using a plate-plate rheometer. It came out that the four techniques used in the assessment of the rheological behavior of such materials are appropriate, complementary and successful. The melt flow index and viscosity measurements indicate a resistant flow for the rubber and its starch composites. Even high temperatures do not seem to reduce the viscosity considerably. Nevertheless, small amounts of starch incorporated in the gum will ease the flow to some extent. The materials showed a pseudoplastic behavior, and storage made a slight change in their melt flow index. Morphological studies showed that the particles of starch were not destructed during the mixing and their interaction with the rubbery matrix is very poor.

Purpose: The present study is intended to the preparation and optimization of controlled drug release microparticles based on polylactic acid and Mesalazine. This active ingredient is usually used in the therapy of intestine inflammatory diseases, particularly the Crohn's disease and hemorrhagic recto colitis. Methods: Microencapsulation by simple O/W emulsion solvent evaporation method was used to prepare these formulations. Some of the process variables such as the emulsifier concentration, the polymer concentration, the drug: polymer ratio and stirring speed were varied and the obtained biodegradable microparticles were characterized by FTIR spectroscopy, X-ray diffraction, DSC method and optical microscopy. The drug release was established both in simulated intestinal fluid and distilled water and the data analysis and the release mechanism were investigated on the basis of Higuchi and Korsmeyer-Peppas models. Results: The microparticles' size i.e. the number mean diameter (d10) ranged from 127 to 744 mu m and the drug content varied from 12 to 27%. The effect of the selected variables on the microparticles' characteristics (size, morphology and drug release) were exhaustively discussed for the PLA/mesalazine microparticles' optimization. Conclusion: This study showed that the microparticles' morphology depended strongly on the emulsifier concentration and the drug entrapment is related to the initial drug: polymer ratio and polymer concentration.

The present paper is devoted to the study of the non-steroidal anti-inflammatory niflumic acid (NA) release from dosage forms in simulated gastric and intestinal liquids (pH=1.2 and 6.8). New formulations (tablets) based on native, pregelatinized and cross-linked (DSA) corn starches were developed and tested. The proposed matrices were used in order to modify the NA release and especially to reduce its gastrointestinal side effect. The cross-linked matrix i.e. distarch adipate (DSA) was obtained by chemical modification of native starch using adipic acid/acetic anhydride. The different starches were characterized by different methods (FTIR, X-ray, swelling power). As well, the effects of the matrix and its concentration on the drug release from tablets were investigated. Finally different mathematical models i.e. zero and first order, Higuchi and Korsmeyer–Peppas models were tested in order to evaluate the release mechanism.

: Nowadays many studies have been focusing on the development of biomaterials obtained from renewable resources to replace fossil based plastics. The famous example is starch which is produced by a wide variety of plants as energy reserve and is available in abundance at a very competitive price. It can easily be transformed into thermoplastic starch (TPS) by addition of a plasticizer. However, TPS suffers from several limitations, such as poor mechanical properties and water sensitivity which did not permit its use in large practical applications. In this study, different formulations, containing commercial corn starch and plasticizers were prepared by the film casting method, after gelatinization of starch in hot aqueous suspensions. To obtain flexible films, two plasticizers were used: glycerol and dioctyl phthalate (DOP). The fact that the DOP displayed an exceptionally poor water affinity, three co-solvents, methanol, ethanol and acetone were added in the aim to improve its solubility. The obtained materials were tested considering the water resistance measured at 25 and at 50 °C, mechanical properties in tension and the differential scanning thermal analysis (DSC). From the obtained results, it seems that the solvent system as well as the plasticizers used affects considerably the properties of the resulting materials.