Insights into the impact of cross-linking processes on physicochemical characteristics and mucoadhesive potential of gellan gum/retrograded starch microparticles as a platform for colonic drug release

2020 ◽  
Vol 55 ◽  
pp. 101445 ◽  
Author(s):  
Valéria Maria de Oliveira Cardoso ◽  
Raul Cesar Evangelista ◽  
Maria Palmira Daflon Gremião ◽  
Beatriz Stringhetti Ferreira Cury
Keyword(s):  
Drug Release ◽  
Physicochemical Characteristics ◽  
Gellan Gum ◽  
Cross Linking ◽  
Retrograded Starch ◽  
The Impact

scholarly journals Comparison of Rheological, Drug Release, and Mucoadhesive Characteristics upon Storage between Hydrogels with Unmodified or Beta-Glycerophosphate-Crosslinked Chitosan

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Emilia Szymańska ◽  
Anna Czajkowska-Kośnik ◽  
Katarzyna Winnicka
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Physicochemical Characteristics ◽  
Vaginal Mucosa ◽  
Drug Release Profile ◽  
Modified Chitosan ◽  
Long Term Storage ◽  
Crosslinked Chitosan ◽  
Chitosan Hydrogels ◽  
The Impact

The physicochemical characteristics of beta-glycerophosphate-crosslinked chitosan hydrogels were investigated upon long-term storage at ambient, accelerated, and refrigerated conditions and compared to unmodified chitosan formulations. Additionally, the impact of chitosan modification on the ex vivo mucoadhesive performance in contact with porcine vaginal mucosa and on the drug release profile from hydrogels was evaluated. Viscosity and mechanical properties of formulations with unmodified chitosan decreased significantly upon storage regardless of tested conditions as a result of hydrolytic depolymerization. Introduction of ion crosslinker exerted stabilizing effect on physicochemical performance of chitosan hydrogels but only upon storage at refrigerated conditions. Beta-glycerophosphate-modified chitosan formulations preserved organoleptic, rheological behavior, and hydrogel structure up to 3-month storage at 4 ± 2°C. Viscosity variations upon storage influenced markedly mucoadhesive properties and drug release rate from hydrogels.

scholarly journals ENCAPSULATION OF ROXITHROMYCIN INTO GELLAN GUM MATRICES AND THE IMPACT OF OTHER NATURAL POLYMERS ON DRUG RELEASE

2020 ◽  
Vol 77 (2) ◽  
pp. 319-330
Author(s):  
Piotr Gadziński ◽  
Anna Froelich ◽  
Urszula Kowalska ◽  
Marcin Soból ◽  
Mirosław Szybowicz ◽  
...  
Keyword(s):  
Drug Release ◽  
Gellan Gum ◽  
Natural Polymers ◽  
The Impact

scholarly journals The Impact of the Ionic Cross-Linking Mode on the Physical and In Vitro Dexamethasone Release Properties of Chitosan/Hydroxyapatite Beads

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4510 ◽  
Author(s):  
Maria Jucélia L. Dantas ◽  
Bárbara Fernanda F. dos Santos ◽  
Albaniza A. Tavares ◽  
Matheus A. Maciel ◽  
Breno de Medeiros Lucena ◽  
...  
Keyword(s):  
Drug Release ◽  
Release Rate ◽  
Sodium Tripolyphosphate ◽  
In Vitro Release ◽  
Surface Topology ◽  
Cartilage Tissue ◽  
Cross Linking ◽  
Release Process ◽  
The Impact

In this study, the effect of the ionic cross-linking mode on the ability to control physical properties and in vitro release behavior of the dexamethasone (DEX) drug from chitosan (CS) and chitosan/hydroxyapatite (CS/HA) beads was investigated. CS solutions without and with HA and DEX were dripped into two coagulation solutions, prepared with a non-toxic ionic crosslinker (sodium tripolyphosphate, TPP) and distilled water, one at pH = 9.0 and other at pH = 6.0. Optical microscopy (OM) and scanning electron microscopy (SEM) results showed changes on the surface topology of the beads, with a reduction of roughness for beads prepared at pH = 6.0 and an increase for the one prepared at pH = 9.0. The diameter and sphericity of the beads prepared at pH = 6.0 proved more uniform and had a larger pore size with a good interconnectivity framework. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) suggested a higher crosslinking degree for beads prepared at pH = 6.0, corroborated by X-ray diffraction profiles (XRD) analysis that indicated a decrease in the crystalline structure for such beads. In in vitro drug release data, all beads presented a sustained release during the studied period (24 h). The drug release rate was affected by the pH of the coagulation solution used in the preparation of the beads. The in vitro kinetics of the release process was of the Peppas–Sahlin model, controlled by both diffusion and relaxation of polymer chains or swelling (anomalous transport mechanism). Our results suggest that DEX-loaded CS/HA beads, crosslinked in TPP coagulation solution at pH = 9.0, led to a decrease in the DEX release rate and prolonged the release period. Thus, this composition might have prospective as a functional material for bone and cartilage tissue engineering.

scholarly journals Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

2021 ◽  
Author(s):  
Istebreq A. Saeedi ◽  
Sunny Chaudhary ◽  
Thomas Andritsch ◽  
Alun S. Vaughan
Keyword(s):  
Glass Transition ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Epoxy Resins ◽  
Functional Network ◽  
Cross Linking ◽  
Network Modifier ◽  
Epoxy Resin System ◽  
The Cross ◽  
The Impact

AbstractReactive molecular additives have often been employed to tailor the mechanical properties of epoxy resins. In addition, several studies have reported improved electrical properties in such systems, where the network architecture and included function groups have been modified through the use of so-called functional network modifier (FNM) molecules. The study reported here set out to investigate the effect of a glycidyl polyhedral oligomeric silsesquioxane (GPOSS) FNM on the cross-linking reactions, glass transition, breakdown strength and dielectric properties of an amine-cured epoxy resin system. Since many previous studies have considered POSS to act as an inorganic filler, a key aim was to consider the impact of GPOSS addition on the stoichiometry of curing. Fourier transform infrared spectroscopy revealed significant changes in the cross-linking reactions that occur if appropriate stoichiometric compensation is not made for the additional epoxide groups present on the GPOSS. These changes, in concert with the direct effect of the GPOSS itself, influence the glass transition temperature, dielectric breakdown behaviour and dielectric response of the system. Specifically, the work shows that the inclusion of GPOSS can result in beneficial changes in electrical properties, but that these gains are easily lost if consequential changes in the matrix polymer are not appropriately counteracted. Nevertheless, if the system is appropriately optimized, materials with pronounced improvements in technologically important characteristics can be designed.

scholarly journals The Impact of Gelatin on the Pharmaceutical Characteristics of Fucoidan Microspheres with Posaconazole

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4087
Author(s):  
Marta Szekalska ◽  
Aleksandra Citkowska ◽  
Magdalena Wróblewska ◽  
Katarzyna Winnicka
Keyword(s):  
Antifungal Activity ◽  
Drug Release ◽  
Spray Drying ◽  
Fungal Infections ◽  
Drug Loading ◽  
High Surface ◽  
Vaginal Fluid ◽  
Sustained Drug Release ◽  
Candida Spp ◽  
The Impact

Fungal infections and invasive mycoses, despite the continuous medicine progress, are an important globally therapeutic problem. Multicompartment dosage formulations (e.g., microparticles) ensure a short drug diffusion way and high surface area of drug release, which as a consequence can provide improvement of therapeutic efficiency compared to the traditional drug dosage forms. As fucoidan is promising component with wide biological activity per se, the aim of this study was to prepare fucospheres (fucoidan microparticles) and fucoidan/gelatin microparticles with posaconazole using the one-step spray-drying technique. Pharmaceutical properties of designed fucospheres and the impact of the gelatin addition on their characteristics were evaluated. An important stage of this research was in vitro evaluation of antifungal activity of developed microparticles using different Candida species. It was observed that gelatin presence in microparticles significantly improved swelling capacity and mucoadhesiveness, and provided a sustained POS release. Furthermore, it was shown that gelatin addition enhanced antifungal activity of microparticles against tested Candida spp. strains. Microparticles formulation GF6, prepared by the spray drying of 20% fucoidan, 5% gelatin and 10% Posaconazole, were characterized by optimal mucoadhesive properties, high drug loading and the most sustained drug release (after 8 h 65.34 ± 4.10% and 33.81 ± 5.58% of posaconazole was dissolved in simulated vaginal fluid pH 4.2 or 0.1 M HCl pH 1.2, respectively).

The Lateral Cross-Linking of Polyurethane Using Grafted Epichlorohydrin and the Impact on the Tensile and Thermal Properties

2016 ◽  
Vol 37 (2) ◽  
pp. 323-331 ◽  
Author(s):  
Yong-Chan Chung ◽  
Byung Hee Lee ◽  
Jae Won Choi ◽  
Byoung Chul Chun
Keyword(s):  
Thermal Properties ◽  
Cross Linking ◽  
The Impact

Jam processing: Effect of pectin replacement by locust bean gum on its characteristics

2020 ◽  
pp. 1-12
Author(s):  
Aida Mekhoukhe ◽  
Nacer Mohellebi ◽  
Tayeb Mohellebi ◽  
Leila Deflaoui-Abdelfettah ◽  
Sonia Medouni-Adrar ◽  
...  
Keyword(s):  
Cold Water ◽  
Physicochemical Characteristics ◽  
Water Soluble ◽  
Sensory Profile ◽  
Locust Bean Gum ◽  
Locust Bean ◽  
Preference Map ◽  
The Right ◽  
High Level ◽  
The Impact

OBJECTIVE: the present work proposed to extract Locust Bean Gum (LBG) from Algerian carob fruits, evaluate physicochemical and rheological properties (solubility). It aimed also to develop different formulations of strawberry jams with a mixture of LBG and pectin in order to obtain a product with a high sensory acceptance. METHODS: the physicochemical characteristics of LBG were assessed. The impact of temperature on solubility was also studied. The physical and the sensory profile and acceptance of five Jams were evaluated. RESULTS: composition results revealed that LBG presented a high level of carbohydrate but low concentrations of fat and ash. The LBG was partially cold-water-soluble (∼62% at 25°C) and needed heating to reach a higher solubility value (∼89% at 80 °C). Overall, the sensorial acceptances decreased in jams J3 which was formulated with 100% pectin and commercial one (J5). The external preference map explained that most consumers were located to the right side of the map providing evidence that most samples appreciated were J4 and J2 (rate of 80–100%). CONCLUSION: In this investigation, the LBG was used successfully in the strawberry jam’s formulation.

scholarly journals Enhanced Viral Activity in the Surface Microlayer of the Arctic and Antarctic Oceans

2021 ◽  
Vol 9 (2) ◽  
pp. 317
Author(s):  
Dolors Vaqué ◽  
Julia A. Boras ◽  
Jesús Maria Arrieta ◽  
Susana Agustí ◽  
Carlos M. Duarte ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Food Web ◽  
Physicochemical Characteristics ◽  
The Arctic ◽  
Microbial Food Web ◽  
Surface Microlayer ◽  
Polar Regions ◽  
Nutrient Inputs ◽  
Viral Activity ◽  
The Impact

The ocean surface microlayer (SML), with physicochemical characteristics different from those of subsurface waters (SSW), results in dense and active viral and microbial communities that may favor virus–host interactions. Conversely, wind speed and/or UV radiation could adversely affect virus infection. Furthermore, in polar regions, organic and inorganic nutrient inputs from melting ice may increase microbial activity in the SML. Since the role of viruses in the microbial food web of the SML is poorly understood in polar oceans, we aimed to study the impact of viruses on prokaryotic communities in the SML and in the SSW in Arctic and Antarctic waters. We hypothesized that a higher viral activity in the SML than in the SSW in both polar systems would be observed. We measured viral and prokaryote abundances, virus-mediated mortality on prokaryotes, heterotrophic and phototrophic nanoflagellate abundance, and environmental factors. In both polar zones, we found small differences in environmental factors between the SML and the SSW. In contrast, despite the adverse effect of wind, viral and prokaryote abundances and virus-mediated mortality on prokaryotes were higher in the SML than in the SSW. As a consequence, the higher carbon flux released by lysed cells in the SML than in the SSW would increase the pool of dissolved organic carbon (DOC) and be rapidly used by other prokaryotes to grow (the viral shunt). Thus, our results suggest that viral activity greatly contributes to the functioning of the microbial food web in the SML, which could influence the biogeochemical cycles of the water column.

Probiotic Greek yogurt: effect of the addition of prebiotic fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance

2021 ◽  
Vol 88 (1) ◽  
pp. 98-104
Author(s):  
Sofia Sestito Dias ◽  
Damarys de Souza Vergílio ◽  
Arthur Marroni Pereira ◽  
Suellen Jensen Klososki ◽  
Vanessa Aparecida Marcolino ◽  
...  
Keyword(s):  
Negative Impact ◽  
Storage Period ◽  
Titratable Acidity ◽  
Physicochemical Characteristics ◽  
Modified Starch ◽  
Sensory Acceptance ◽  
Ph Values ◽  
Fat Substitutes ◽  
Gastrointestinal Conditions ◽  
The Impact

AbstractIn this research communication we evaluate the impact of the addition of prebiotic components (inulin, polydextrose, and modified starch, 40 g/l) as fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance of probiotic (Lacticaseibacillus casei 01, 108 CFU/ml) Greek yogurts during storage (7 °C, 28 d). All formulations had probiotic counts higher than 107 CFU/ml during storage and simulated gastrointestinal conditions (SGIC). The prebiotic components increased the probiotic survival to the enteric phase of the SGIC, with inulin producing the most pronounced effect. Inulin addition resulted in products with lower pH values and consistency and higher titratable acidity during storage, with negative impact on the sensory acceptance (flavor, texture, and overall impression) at the end of the storage period. Modified starch addition impacted negatively on the acceptance of the products (appearance, flavor, texture, and overall impression). Polydextrose addition resulted in products with lower consistency, but similar sensory acceptance to the full-fat yogurt. It can be concluded that it is possible to prepare potentially synbiotic Greek yogurts by desorption technique using L. casei as probiotic culture and inulin, polydextrose or modified starch as prebiotic components, with the utilization of polydextrose being advisable.

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