229 research outputs found
Understanding Urea Encapsulation in Different Clay Minerals as a Possible System for Ruminant Nutrition
Considering the challenges of urea administration due to the high ureolytic activity of
the rumen and the importance of its use, as well as taking into account the relevance of sustainably
exploiting the technological potential of biodiversity, this research studies the encapsulation of urea
in different clay minerals (palygorskite (Pal), sepiolite (Sep), and Veegum® (V)) as an alternative for
use as nonprotein nitrogen (NNP) sources. A method of incorporation was developed in which the
encapsulation of urea was proven by X-ray diffraction; fibrous materials, Pal and Sep had similar
characteristics due to the decrease in the relative plane intensity (011), suggesting a decrease in the
order of their stacking due to the presence of urea on the surface or inside channels. By contrast,
V showed a 7.74Âş reflection shift, suggesting an increase in basal spacing from 11.45 Ă… in V to 14.88 Ă…
in the sample after urea encapsulation. By thermogravimetry, it was observed that the presence of urea
did not change the mass-loss profiles but only increased the percentage of loss in respective events,
indicating urea incorporation in the clay minerals. These results provide a promising alternative for
administering NNP sources in the ruminant diet
Hybrid Systems Based on Talc and Chitosan for Controlled Drug Release
Inorganic matrices and biopolymers have been widely used in pharmaceutical fields. They
show properties such as biocompatibility, incorporation capacity, and controlled drug release, which
can become more attractive if they are combined to form hybrid materials. This work proposes the
synthesis of new drug delivery systems (DDS) based on magnesium phyllosilicate (Talc) obtained by
the sol–gel route method, the biopolymer chitosan (Ch), and the inorganic-organic hybrid formed
between this matrix (Talc + Ch), obtained using glutaraldehyde as a crosslink agent, and to study
their incorporation/release capacity of amiloride as a model drug. The systems were characterized
by X-ray diffraction (XRD), Therma analysis TG/DTG, and Fourier-transform infrared spectroscopy
(FTIR) that supported the DDS’s formation. The hybrid showed a better drug incorporation capacity
compared to the precursors, with a loading of 55.74, 49.53, and 4.71 mg g-1 for Talc + Ch, Talc, and
Ch, respectively. The release assays were performed on a Hanson Research SR-8 Plus dissolver
using apparatus I (basket), set to guarantee the sink conditions. The in vitro release tests showed a
prolongation of the release rates of this drug for at least 4 h. This result proposes that the systems
implies the slow and gradual release of the active substance, favoring the maintenance of the plasma
concentration within a therapeutic window.This research was funded by FAPEPI to Caio C. Coelho for Scientific Initiation scholarshi
Clay Mineral Minerals as a Strategy for Biomolecule Incorporation: Amino Acids Approach
The authors thank CAPES, CNPq, and UFPI for financial and/or structural support.The potential use of amino acids by ruminal microorganisms converting them into microbial
protein for ruminants makes it challenging to supplement these nutrients in an accessible
form in animals’ diets. Several strategies to protect amino acids from ruminal degradation were
reported, producing amino acids available for the protein used in the intestine called “bypass.”
The intercalation of biomolecules in clay mineral minerals has gained notoriety due to its ability
to support, protect, transport, physicochemical properties and non-toxicity. This study aimed to
investigate the incorporation of L-lysine (Lys), L-methionine (Met), and L-tryptophan (Trp) amino
acids in the clay minerals sepiolite (Sep) and Veegum® (Veg) using the adsorption method. The
characterization techniques of X-ray diffraction and infrared spectroscopy indicated the presence of
biomolecules in the inorganic matrices. Elemental and thermal analyzes monitored the percentages
of incorporated amino acids. They showed better incorporation capacities for Veg, such as Met-Veg
< Lys-Veg < Trp-Veg and Lys-Sep < Met-Sep < Trp-Sep for sepiolite, except for the incorporation of
Met. Matrices provide a promising alternative for planning the administration of biomolecules, using
essential amino acids as models, and may offer an alternative to improve functional diet strategies.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)UFP
Diseño de una guĂa de prácticas de laboratorio de acuerdo con las orientaciones del EEES
La adaptaciĂłn de la docencia universitaria al Espacio Europeo de EducaciĂłn Superior (EEES) supone un cambio en los sistemas de enseñanza actual. En este sentido el desarrollo de guĂas de laboratorio capaces de informar al alumnado, y normalizar la confecciĂłn y presentaciĂłn de las prácticas de laboratorio, asegurando una mejor calidad de la docencia y coordinaciĂłn entre grupos, viene a cumplir con algunos de los objetivos pretendidos en el contexto de la Convergencia Europea. La GuĂa que se presenta, destinada a su empleo en la docencia práctica de una asignatura troncal de la licenciatura en Farmacia en la Universidad de Granada, recoge las indicaciones necesarias para llevar a cabo un trabajo seguro y eficiente en los laboratorios
Clays as Vehicles for Drug Photostability
This research was financially supported by Junta de Andalucia, under the project reference PT18 RT 3786.Clay minerals are often used due to their high adsorption capacity, which has sparked interest
in their biological applications to stabilize drugs and pharmaceutical products. This research aims
to summarize information about the stability of drugs, cosmetics, dermocosmetics, and pharmaceutical
compounds incorporated in the structure of different clay minerals. The databases used to search
the articles were Web of Science, Scopus, PubMed, and Science Direct. Photostabilization of these
compounds is reviewed and its importance demonstrated. For biological applications, the increase
in solubility and bioavailability of clay minerals has proven useful for them as drug carriers. While
their natural abundance, low toxicity, and accessible cost have contributed to classical applications
of clay minerals, a wide range of interesting new applications may be facilitated, mainly through
incorporating different organic molecules. The search for new functional materials is promising to
challenge research on clay minerals in biological or biotechnological approaches.Junta de Andalucia PT18 RT 378
Paludibacterium
Curved rods, non-spore forming and Gram-negative. Motile by means of a single polar flagellum. Facultative anaerobe. Reacts positively for the catalase and cytochrome c oxidase tests. Nitrate reduction is variable among genus members and indole is not produced. The major respiratory quinone is ubiquinone 8 (Q-8). Fatty acid composition is variable within the genus, although summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) and C16:0 are predominant in all species. The polar lipid profile consists of phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), among other unidentified aminophospholipids, phospholipids, and polar lipids.info:eu-repo/semantics/acceptedVersio
Effect of acid treatment on the structure of sepiolite.
An ab initio determination of the structure of sepiolite after acid treatment (HCl 0.5 N for 24 h) was carried out using X-ray powder diffraction data. After acid treatment, the sections normal to the a and c axes presented discontinuities, ~2.25 Ă… wide, parallel to the (010) plane, with no electronic density maxima, thus suggesting that adjacent planes are joined by van der Waals-like residual links. Partial dissolution was detected on both octahedral and tetrahedral sheets, beginning by breaking the ribbons not along the edges, but in the centre, thus creating a 5.20x6.79 Ă… tunnel along the a axis. By interrupting the tetrahedral sheet, this mechanism changes the phyllosilicate-like nature of the sepiolite to an inosilicate-like structure.Peer reviewe
Zeolites as Ingredients of Medicinal Products
Development of new medicinal products for particular therapeutic treatment or for better
manipulations with better quality and less side effects are possible as a result of advanced inorganic
and organic materials application, among which zeolites, due to their properties and versatility, have
been gaining attention. This paper is an overview of the development in the use of zeolite materials
and their composites and modifications as medicinal products for several purposes such as active
agents, carriers, for topical treatments, oral formulations, anticancer, the composition of theragnostic
systems, vaccines, parenteral dosage forms, tissue engineering, etc. The objective of this review is
to explore the main properties of zeolites and associate them with their drug interaction, mainly
addressing the advances and studies related to the use of zeolites for different types of treatments due
to their zeolite characteristics such as molecule storage capacity, physical and chemical stability, cation
exchange capacity, and possibility of functionalization. The use of computational tools to predict the
drug—zeolite interaction is also explored. As conclusion was possible to realize the possibilities and
versatility of zeolite applications as being able to act in several aspects of medicinal products
Ground calcium carbonate as a low cost and biosafety excipient for solubility and dissolution improvement of praziquantel
Calcium carbonate is an abundant mineral with several advantages to be a successful carrier to improve oral bioavailability of poorly water-soluble drugs, such as praziquantel. Praziquantel is an antiparasitic drug classified in group II of the Biopharmaceutical Classification System hence characterized by high-permeability and low-solubility. Therefore, the dissolution rate is the limiting factor for the gastrointestinal absorption that contributes to the low bioavailability. Consequently, the therapeutic dose of the praziquantel must be high and big tablets and capsules are required, which are difficult to swallow, especially for pediatric and elderly patients. Mixtures of praziquantel and calcium carbonate using solid-solid physical mixtures and solid dispersions were prepared and characterized using several techniques (X-ray diffraction differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, laser diffraction, Fourier transform infrared and Raman spectroscopies). Solubility of these formulations evidenced that the solubility of praziquantel-calcium carbonate interaction product increased in physiological media. In vitro dissolution tests showed that the interaction product increased the dissolution rate of the drug in acidic medium. Theoretical models were studied to understand this experimental behavior. Cytotoxicity and cell cycle studies were performed, showing that praziquantel-calcium carbonate physical mixture and interaction product were biocompatible with the HTC116 cells, because it did not produce a decrease in cell viability or alterations in the cell cycle
Nanoformulations based on collagenases loaded into halloysite/Veegum® clay minerals for potential pharmaceutical applications
The design and development of nanomaterials capable of penetrate cancer cells is fundamental when anticancer therapy is involved. The use of collagenase (Col) is useful since this enzyme can degrade collagen, mainly present in the tumor extracellular matrix. However, its use is often limited since collagenase suffers from inactivation and short half-life. Use of recombinant ultrapure collagenase or carrier systems for their delivery are among the strategies adopted to increase the enzyme stability. Herein, based on the more stability showed by recombinant enzymes and the possibility to use them in anticancer therapy, we propose a novel strategy to further increase their stability by using halloysite nanotubes (HNTs) as carrier. ColG and ColH were supramolecularly loaded onto HNTs and used as fillers for Veegum gels. The systems could be used for potential local administration of collagenases for solid tumor treatment. All techniques adopted for characterization showed that halloysite interacts with collagenases in different ways depending with the Col considered. Furthermore, the hydrogels showed a very slow release of the collagenases within 24 h. Finally, biological assays were performed by studying the digestion of a type-I collagen matrix highlighting that once released the Col still possessed some activity. Thus we developed carrier systems that could further increase the high recombinant collagenases stability, preventing their inactivation in future in vivo applications for potential local tumor treatment
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