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2.
J Environ Sci (China) ; 87: 10-23, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31791484

RESUMO

Five biochars derived from lotus seedpod (LSP) were applied to examine and compare the adsorption capacity of 17ß-estradiol (E2) from aqueous solution. The effect of KOH activation and the order of activation steps on material properties were discussed. The effect of contact time, initial concentration, pH, ionic strength and humic acid on E2 adsorption were investigated in a batch adsorption process. Experimental results demonstrated that the pseudo second-order model fitted the experimental data best and that adsorption equilibrium was reached within 20 hr. The efficiency of E2 removal increased with increasing E2 concentration and decreased with the increase of ionic strength. E2 adsorption on LSP-derived biochar (BCs) was influenced little by humic acid, and slightly affected by the solution pH when its value ranged from 4.0 to 9.0, but considerably affected at pH 10.0. Low environmental temperature is favorable for E2 adsorption. Chemisorption, π-π interactions, monolayer adsorption and electrostatic interaction are the possible adsorption mechanisms. Comparative studies indicated that KOH activation and the order of activation steps had significant impacts on the material. Post-treated biochar exhibited better adsorption capacity for E2 than direct treated, pre-treated, and raw LSP biochar. Pyrolyzed biochar at higher temperature improved E2 removal. The excellent performance of BCs in removing E2 suggested that BCs have potential in E2 treatment and that the biochar directly treated by KOH would be a good choice for the treatment of E2 in aqueous solution, with its advantages of good efficiency and simple technology.


Assuntos
Estradiol/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Carvão Vegetal , Temperatura Alta , Substâncias Húmicas , Concentração de Íons de Hidrogênio , Hidróxidos , Cinética , Lotus , Concentração Osmolar , Compostos de Potássio , Sementes , Temperatura Ambiente
3.
Farm. hosp ; 43(5): 163-165, sept.-oct. 2019. tab
Artigo em Espanhol | IBECS | ID: ibc-183929

RESUMO

Objetivo: Determinar experimentalmente si micafungina y anidulafungina poseen propiedades fisicoquímicas adecuadas para su nebulización. Método: Se determinó el pH, la osmolalidad, la viscosidad, la densidad y el contenido en cloruros mediante pH-metría, osmometría, viscosimetría, densitometría y potenciometría, respectivamente, en dos muestras de diferente concentración, 5 y 10 mg/ml, de cada equinocandina. Resultados: Para la solución de micafungina 5 mg/ml los resultados obtenidos fueron: pH 5,80 (0,14), osmolalidad 293,33 (1,53) mOsm/kg, contenido en cloruros 134,67 (0,58) mmol/l y densidad 1.009,4 (0,1) kg/m3; y para la solución de 10 mg/ml: osmolalidad 342,00 (1,00) mOsm/kg, contenido en cloruros 139,67 (0,58) mmol/l y densidad 1.014,5 (0,2) kg/m3. Para la solución de anidulafungina 5 mg/ml los resultados obtenidos fueron: pH 4,22 (0,01), osmolalidad 464,67 (2,52) mOsm/kg, contenido en cloruros 137,00 (0,00) mmol/l y densidad 1.016,5 (0,2) kg/m3; y para la solución de 10 mg/ml: osmolalidad 656,33 (1,15) mOsm/kg, contenido en cloruros 132,00 (0,00) mmol/l y densidad 1.029,8 (0,4) kg/m3. Conclusiones: Los valores de pH, osmolalidad, contenido en cloruros y densidad resultaron adecuados para una correcta tolerabilidad mediante nebulización


Objective: To determine by experimentation whether micafungin and anidulafungin possess physicochemical properties suitable for nebulization. Method: PH, osmolality, viscosity, density and chloride content were determined by pH monitoring, osmometry, viscometry, densitometry and potentiometry in two samples of different concentrations, 5 and 10 mg/mL each echinocandin. Results: The results obtained for micafungin solution were: pH 5.80 (0.14), osmolality 293.33 (1.53) mOsm/kg, chloride content 134.67 (0.58) mmol/L and density 1,009.4 (0,1) kg/m3; while for 10 mg/mL solution: osmolality 342.00 (1.00) mOsm/kg, chloride content 139.67 (0.58) mmol/L and density 1,014.5 (0.2) kg/m3. The results obtained for 5 mg/mL anidulafungin were: pH 4.22 (0.01), osmolality 464.67 (2.52) mOsm/kg, chloride content 137.00 (0.00) mmol/L and density 1,016.5 (0,2) kg/m3; while for 10 mg/mL solution: osmolality 656.33 (1.15) mOsm/kg, chloride content 132.00 (0.00) mmol/L and density 1,029.8 (0.4) kg/m3. Conclusions: PH, osmolality, chloride content and density values proved to be suitable for proper tolerability by nebulization


Assuntos
Micafungina/química , Anidulafungina/química , Nebulizadores e Vaporizadores , Química Física/métodos , Absorção Fisico-Química/efeitos dos fármacos , Administração por Inalação , Concentração de Íons de Hidrogênio , Concentração Osmolar , Viscosidade , Equinocandinas/análise
4.
Eur J Pharm Biopharm ; 144: 207-216, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521717

RESUMO

Reducing the aggregation of proteins is of utmost interest to the pharmaceutical industry. Aggregated proteins are often less active and can cause severe immune reactions in the patient upon administration. At the same time the biopharmaceutical market is pushing for high concentration formulations and products that do not require refrigerated storage conditions. For a given protein, the only solution pH, ionic strength and concentration of a very limited number of excipients are the only parameters that can be varied to obtain a stable formulation. In this work, we present a structure-based approach to discover new molecules that successfully reduce the aggregation of proteins and apply the approach to the model protein Interferon-alpha-2a.


Assuntos
Preparações Farmacêuticas/química , Agregados Proteicos/efeitos dos fármacos , Proteínas/química , Excipientes/química , Concentração de Íons de Hidrogênio , Interferon-alfa/química , Concentração Osmolar
5.
Cesk Slov Oftalmol ; 75(2): 74-77, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31537075

RESUMO

Botulinum toxin type A (BT-A) is used in the treatment of neuro-ophthalmologic disorders such as essential blepharospasm and facial hemispasm for more than 20 years. Although the long-term effect of repeated application of the BT-A was confirmed, the BT-A effect on tears production and retention is not clear. In our work we investigated whether applied BT-A in patients with blepharospasm and hemifacial spasm affect tears production. Tears quality was measured with Schirmers and tear osmolarity test during neuro-ophthalmologic diseases treatment, which was evaluated before and 14 days after application of BT-A (Botox inj, Allergan, Irvine, USA) into the orbicularis oculi muscle. BT-A doses of 16-18 U with unilateral and 32 to 36 U bilateral applications were used. The mean tear production in Schirmers test before BT-A application was 8.38 ± 0.63 mm, and 2 weeks after BT-A application was 7.12 ± 0,6 mm (n = 50). Tear osmolarity was 305.4 ± 9.2 mOsm before BT-A application, and 2 weeks after BT-A application it was 305.2 ± 8,6 mOsm (n = 13). We found significant difference between two groups in tear quantity (p < 0.012), but not quality (p > 0.05). Application of the BT-A reduced the amount of tears measured by Schirmers test. These results confirm rational basis of the empirical clinical experience where an artificial tears substitution is recommended for patients with neuro-ophthalmologic disorders treated by BT-A.


Assuntos
Blefarospasmo , Toxinas Botulínicas Tipo A , Espasmo Hemifacial , Fármacos Neuromusculares , Blefarospasmo/tratamento farmacológico , Toxinas Botulínicas Tipo A/uso terapêutico , Espasmo Hemifacial/tratamento farmacológico , Humanos , Fármacos Neuromusculares/uso terapêutico , Concentração Osmolar , Lágrimas/química
6.
Chemosphere ; 235: 1059-1065, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561295

RESUMO

In subsurface repositories, active bacterial populations may directly influence the fate and transport of radionuclides including in salt repository systems like the Waste Isolation Pilot Plant in Carlsbad, NM. This research quantified the potential for transport and interaction between Chromohalobacter sp. and Cs in a high ionic strength system (2.6 M NaCl) containing natural minerals. Mini-column experiments showed that Chromohalobacter moved nearly un-retarded under these conditions and that there was neither association of Cs with microbes nor dolomite despite changes in bacterial metabolic phases. Growth batch experiments that monitored the potential uptake of Cs into the microbes confirmed results in column experiments where intracellular uptake of Cs by Chromohalobacter was not observed. These results show that Cs may be highly mobile if released in high ionic strength systems and/or carbonate minerals with negligible inhibition by these microbes.


Assuntos
Césio/metabolismo , Transporte Biológico , Carbonato de Cálcio , Césio/farmacocinética , Chromohalobacter/metabolismo , Coloides/metabolismo , Magnésio , Minerais , Concentração Osmolar , Radioisótopos
7.
Phys Chem Chem Phys ; 21(34): 18727-18740, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31424463

RESUMO

The plant stress protein COR15A stabilizes chloroplast membranes during freezing. COR15A is an intrinsically disordered protein (IDP) in aqueous solution, but acquires an α-helical structure during dehydration or the increase of solution osmolarity. We have used small- and wide-angle X-ray scattering (SAXS/WAXS) combined with static and dynamic light scattering (SLS/DLS) to investigate the structural and hydrodynamic properties of COR15A in response to increasing solution osmolarity. Coarse-grained ensemble modelling allowed a structure-based interpretation of the SAXS data. Our results demonstrate that COR15A behaves as a biomacromolecule with polymer-like properties which strongly depend on solution osmolarity. Biomacromolecular self-assembly occurring at high solvent osmolarity is initiated by the occurrence of two specific structural subpopulations of the COR15A monomer. The osmolarity dependent structural selection mechanism is an elegant way for conformational regulation and assembly of COR15A. It highlights the importance of the polymer-like properties of IDPs for their associated biological function.


Assuntos
Proteínas de Arabidopsis/química , Proteínas Intrinsicamente Desordenadas/química , Concentração Osmolar , Conformação Proteica , Espalhamento a Baixo Ângulo , Solventes/química , Raios X
8.
J Agric Food Chem ; 67(36): 10155-10164, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31433944

RESUMO

Stabilization of Pickering emulsions via particles of biological origin exhibits a great potential to be widely applied in food, cosmetic, or biomedicine formulation because of their excellent biocompatibility, biodegradability, and functional properties. This paper describes the successful development of a bioderived GroEL protein nanobarrel as a Pickering stabilizer and its protective properties on ß-carotene in dispersed oil phase, as a model of labile bioactive compounds. It is shown that the GroEL nanobarrel is highly surface-active and allows the formation of Pickering emulsion by physical adsorption at the oil/water interface. The optimized formulation for generating a stable submicron oil droplet by ultrasonication includes a GroEL concentration of 0.05-0.45 wt % with an oil/water volume ratio of 0.05-0.35. The as-prepared Pickering emulsion shows pH-responsive emulsification/demulsification transition and excellent stability at temperatures less than 65 °C and ionic strength (with NaCl addition) up to 500 mM. Meanwhile, the emulsion tends to form a gel-like network structure with the oil/water ratio increasing. Finally, we demonstrate that possible factors of oxidant, reducing agent, UV radiation, and sucrose have sequentially decreasing to no effect on the stability of ß-carotene encapsulated in GroEL-stabilized Pickering emulsion and that higher GroEL concentration can significantly reduce ß-carotene degradation rate, thus ensuring more efficient long-term storage. We believe that the emulsion system supported by the GroEL nanobarrel could be developed to a viable tool for delivering lipophilic bioactive compounds.


Assuntos
Chaperoninas/química , Fixadores/química , Óleos/química , Água/química , Emulsões/química , Interações Hidrofóbicas e Hidrofílicas , Nanoestruturas/química , Concentração Osmolar , Tamanho da Partícula , Temperatura Ambiente , beta Caroteno/química
9.
Int J Nanomedicine ; 14: 5159-5173, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31371954

RESUMO

Introduction: The use of liposomes as a drug delivery carrier (DDC) for the treatment of various diseases, especially cancer, is rapidly increasing, requiring more stringent synthesis, formulation, and preservation techniques to bolster safety and efficacy. Liposomes otherwise referred to as phospholipid vesicles are self-assembled colloidal particles. When formed in either the micrometer or nanometer size range, they are ideal candidates as DDC because of their biological availability, performance, activity, and compatibility. Defining and addressing the critical quality attributes (CQAs) along the pharmaceutical production scale will enable a higher level of quality control for reproducibility. More specifically, understanding the CQAs of nanoliposomes that dictate its homogeneity and stability has the potential to widen applications in biomedical science. Methods: To this end, we designed a study that aimed to define synthesis, characterization, formulation (encapsulation), preservation, and cargo delivery and trafficking as the major components within a target product profile for nanoliposomes. A series of synthetic schemes were employed to measure physicochemical properties relevant to nanomaterial drug product development, including concentration gradients, probe versus bath sonication, and storage temperature measured by microscopy (electron and light) and dynamic light scattering. Results: Concentration was found to be a vital CQA as reducing concentrations resulted in nanometer-sized liposomes of <350 nm. Liposomes were loaded with microRNA and fluorescence spectroscopy was used to determine loading efficacy and stability over time. Lyophilization was used to create a dry powder formulation that was then assessed for stability for 6 months. Lastly, breast cancer cell lines were used to ensure efficacy of microRNA delivery and localization. Conclusion: We conclude that microRNA can be loaded into nanometer-sized liposomes, preserved for months in a dried form, and maintain encapsulation after extended time periods in storage.


Assuntos
Neoplasias da Mama/terapia , Lipossomos/química , MicroRNAs/administração & dosagem , Nanopartículas/química , Tamanho da Partícula , Linhagem Celular Tumoral , Feminino , Humanos , Nanopartículas/ultraestrutura , Concentração Osmolar , Reprodutibilidade dos Testes
10.
Sci Total Environ ; 691: 1119-1126, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466193

RESUMO

Environmental pollution caused by microplastics (MPs) and pesticides has become a global challenge, and increasing evidence shows that MPs can adsorb organic pollutants which may affect their distribution and bioavailability. As widely used pesticides, triazole fungicides with potential environmental and human safety risks often coexist with MPs in the environment. Understanding the adsorption behavior is the basis of risk assessment of co-exposure of MPs and triazole fungicides. In this study, the adsorption behavior of three commonly used triazole fungicides on polystyrene (PS) was studied using adsorption test. The influences of PS particle size and environmental factors on adsorption capacity were evaluated, and the adsorption mechanisms were discussed. Results suggested that the adsorption kinetics and isotherm conformed to the Pseudo-second-order and Freundlich model, respectively. The order of adsorption and desorption capacity was hexaconazole (HEX) > myclobutanil (MYC) > triadimenol (TRI), which was positively correlated with LogKow of pesticides. To a certain extent, the decrease in PS particle size and change in solution pH value and increase in salt ion strength all contribute to increasing adsorption capacity. The main mechanisms of adsorption were hydrophobic and electrostatic interactions. MPs can adsorb and may become the source and sink of triazole fungicides in aqueous environments. Our results demonstrate that more attention should be given to the combined water pollution risk of MPs and triazoles fungicides.


Assuntos
Fungicidas Industriais/química , Plásticos/química , Poliestirenos/química , Triazóis/química , Adsorção , Interações Hidrofóbicas e Hidrofílicas , Cinética , Concentração Osmolar
11.
Arq. bras. med. vet. zootec. (Online) ; 71(4): 1286-1292, jul.-ago. 2019. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1038595

RESUMO

Queixada (Tayassu pecari) é um mamífero neotropical, classificado como vulnerável devido à caça e à destruição de seu habitat. Em razão das dificuldades na reprodução em cativeiro, técnicas de reprodução assistida podem ser aplicadas em programas de repovoamento da espécie. Dessa forma, objetivou-se identificar o melhor protocolo de teste hiposmótico (HOST) para avaliar a integridade funcional dos espermatozoides de queixada. O sêmen de quatro machos adultos foi coletado com auxílio de eletroejaculador após contenção física e protocolo de sedação e anestesia. O sêmen foi avaliado quanto às características macro e microscópicas e diluído nas seguintes soluções hiposmóticas: água destilada (0mOsmol/L), sacarose (50, 100, 150mOsm/L) e frutose (50, 100, 150mOsm/L). Cada amostra foi incubada em duplicata, e uma sofreu fixação em solução de citrato de sódio formolizado a 4%. Duzentos espermatozoides foram avaliados por amostra e classificados em reativos ou não ao HOST. Todas as soluções testadas foram semelhantes em identificar o percentual de espermatozoides reativos, independentemente de a amostra ser ou não fixada (P>0,05). Dessa forma, pode-se usar água destilada como HOST por este apresentar resultados similares e por ser um teste mais barato.(AU)


White-lipped peccary (Tayassu pecari) is a neotropical mammal classified as vulnerable due to overhunting and habitat destruction. Due to the low reproduction success in captivity, assisted reproduction techniques can be used in re-stocking programs. Therefore, we aimed to identify the best hyposmotic swelling test (HOST) to evaluate the functional integrity of peccary sperm. Semen samples of four adult males were collected with the aid of an electroejaculator after physical contention, sedation and anesthesia protocols. The semen was evaluated for macro and microscopic characteristics and diluted in the following hyposmotic solutions: distilled water (0mOsmol/L), sucrose (50, 100, 150mOsm/L) and fructose (50, 100, 150mOsm/L). Each sample was incubated in duplicate and one was fixed in 4% formalized sodium citrate solution. Two hundred spermatozoa were evaluated from each sample and classified as reactive or not- reactive to HOST. There were similar proportions of reactive and functional sperm regardless of whether the sample was fixed or not fixed (P> 0.05). Therefore, distilled water can be used as HOST to evaluate the functional integrity of white-lipped peccary sperm because it shows similar results and it is a cheaper test.(AU)


Assuntos
Animais , Masculino , Concentração Osmolar , Artiodáctilos , Análise do Sêmen/métodos , Análise do Sêmen/veterinária , Água Destilada
12.
J Sci Food Agric ; 99(15): 6731-6740, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31350863

RESUMO

BACKGROUND: Common oil-in-water plant-based emulsions are allergenic and unstable to environmental stress, leading to increased consumer concerns about the food industry. To solve the problem of safety and instability, we investigated the influence of environmental stress on the stability of emulsions containing various rice protein hydrolysates, and compared the performance to whey protein, a common food emulsifier. RESULTS: Rice protein hydrolysates were obtained by enzymatic hydrolysis with different proteases (neutrase, trypsin and alcalase). We evaluated the stability of emulsions produced with different hydrolysates according to storage, pH, ionic strength and thermal processing. Trypsin hydrolysates formed emulsion as stable as emulsion containing whey protein against a range of environmental stress containing pH (pH 6 to 7), salt (< 150 mmol L-1 NaCl) and temperature (30-90 °C). Moreover, a higher partition coefficient of protein in emulsion showed that the trypsin hydrolysates were easy to adsorb at the oil-water droplet interface, indicating its higher stability. CONCLUSION: The results obtained in the present study suggest that trypsin hydrolysates could be utilized as natural emulsifiers to stabilize emulsion instead of traditional animal-based emulsifiers, opening many opportunities with respect to hypoallergenic emulsion systems in the food industry. © 2019 Society of Chemical Industry.


Assuntos
Metaloendopeptidases/química , Oryza/química , Hidrolisados de Proteína/química , Subtilisinas/química , Tripsina/química , Biocatálise , Emulsões/química , Concentração de Íons de Hidrogênio , Concentração Osmolar
13.
Food Chem ; 300: 125245, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31352287

RESUMO

The natural bioactive polysaccharide was regarded as the effective nanocarrier for delivery of active ingredients for its biocompatibility and biodegradability. Moreover, the Fructus Mori polysaccharide has been proved to have good antioxidant and hypoglycemic activities. In this study, the Fructus Mori polysaccharide particles were prepared using antisolvent precipitation method. The bioactive polysaccharide particles exhibited smaller and rounder as the increase of the ethanol/water ratio. The average size, polydispersity index (PDI) and ξ-potential of the bioactive polysaccharide particles were 396.06 nm, 0.38 and -21.23 mV at ethanol/water ratio of 20:1. After spheroidization, the polysaccharide particles exhibited more stable when exposed to heat, increased ionic strength and alkaline conditions. Furthermore, the bioactive polysaccharide particle with the smallest size had the strongest protein adsorption capacity and bioavailability. Especially, the MFP-NP3 showed the ORAC value of 917.06 ±â€¯34.13 µmol TE/g, and the α-glucosidase inhibitory activity of 56.98 ±â€¯1.19% at 0.5 mg/mL. In addition, compared to the native Fructus Mori polysaccharide, the spheroidization enhanced the antioxidant ability and hypoglycemic activity.


Assuntos
Antioxidantes/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Morus/química , Nanopartículas/química , Polissacarídeos/química , Polissacarídeos/farmacocinética , Adsorção , Animais , Antioxidantes/química , Disponibilidade Biológica , Precipitação Química , Etanol , Frutas , Inibidores de Glicosídeo Hidrolases/química , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Masculino , Concentração Osmolar , Tamanho da Partícula , Ratos , Solventes/química
14.
Environ Pollut ; 253: 351-357, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325879

RESUMO

The influence of titanium dioxide nanoparticles (nTiO2) on the transport and deposition of polystyrene microplastics (MPs) in saturated quartz sand was investigated in NaCl solutions with ionic strengths from 0.1 to 10 mM at two pH conditions (pH 5 and 7). Three different-sized polystyrene (PS) MPs (diameter of 0.2, 1, and 2 µm) were concerned in present study. We found that for all three different-sized MPs in NaCl solutions (0.1, 1 and 10 mM) at both pH 5 and 7, lower breakthrough curves and higher retained profiles of MPs with nTiO2 copresent in suspensions relative to those without nTiO2 were obtained, demonstrating that the copresence of nTiO2 in MPs suspensions decreased MPs transport and increased their deposition in quartz sand under all examined conditions. The mechanisms contributing to the increased MPs deposition with nTiO2 in suspensions at two pH conditions were different. The formation of MPs-nTiO2 heteroaggregates and additional deposition sites provided by previously deposited nTiO2 were found to drive to the increased MPs deposition with nTiO2 in suspensions at pH 5, while the formation of MPs-nTiO2 aggregates, additional deposition sites and increased surface roughness induced by the pre-deposited nTiO2 on quartz sand surfaces were responsible for the enhanced MPs deposition at pH 7. The results give insights to predict the fate and transport of different-sized MPs in porous media in the copresence of engineered nanoparticles.


Assuntos
Nanopartículas/química , Plásticos/química , Quartzo/química , Titânio/química , Concentração Osmolar , Poliestirenos , Porosidade , Dióxido de Silício/química , Cloreto de Sódio , Suspensões
15.
AAPS PharmSciTech ; 20(7): 265, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31342285

RESUMO

Here we investigated the disintegration action of the natural superdisintegrant soy polysaccharide (SP) and benchmarked it against sodium starch glycolate (SSG) and crospovidone (XPVP). Kinetics and mechanism of disintegration of various tablet formulations were monitored using a USB microscope connected to a computer, followed by image analysis. SP acts mainly by a swelling mechanism and it is most effective at concentrations of 4-8%. Its disintegration action is comparable with that of SSG and XPVP, in most cases. However, SP underperforms compared with these superdisintegrants, in extremely hard tablets containing a hydrophobic component. Moreover, it is more negatively affected by the concentration of magnesium stearate than SSG and XPVP. The disintegration action of SP is not affected by pH and ionic strength of the medium, but it is compromised by the presence of ethanol. This indicates that the concomitant administration of alcoholic beverages might hamper the disintegration of SP-containing tablets. Overall, SP is a promising tablet disintegrant for pharmaceutical and nutraceutical products.


Assuntos
Polissacarídeos/química , Povidona/química , Soja/química , Composição de Medicamentos , Excipientes/química , Interações Hidrofóbicas e Hidrofílicas , Cinética , Concentração Osmolar , Solubilidade , Comprimidos/química , Resistência à Tração
16.
Curr Med Chem ; 26(22): 4241-4252, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31345142

RESUMO

Glaucoma is the second leading cause of blindness in the world, affecting more than 60 million people globally. In order to reduce the progression of the disease, both medical and surgical treatments are used. Frequent side effects of both treatments include a range of modifications of the ocular surface grouped as the Ocular Surface Disease (OSD), which include Dry Eye Disease (DED). DED and other OSD negatively impact on the success of anti-glaucoma treatments and reduce the adherence to medical therapies. Tear film osmolarity (TFO) is a relatively novel test which has become a hallmark of DED. The aim of this paper was to review the association between OSD, DED and glaucoma in view of published TFO data, and to discuss future fields of research and treatments on the topic of glaucoma iatrogenic damage.


Assuntos
Anti-Hipertensivos/farmacologia , Doenças da Córnea/tratamento farmacológico , Glaucoma/tratamento farmacológico , Conservantes Farmacêuticos/farmacologia , Lágrimas/efeitos dos fármacos , Animais , Anti-Hipertensivos/química , Humanos , Concentração Osmolar , Conservantes Farmacêuticos/química , Propriedades de Superfície
17.
Environ Pollut ; 253: 221-230, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310872

RESUMO

There is a need to develop highly efficient materials for capturing uranium from nuclear wastewater. Here, 5-methylbenzotriazole modified graphene oxide (MBTA-GO) was used to adsorb U(VI) from aqueous solution. By the trials of different conditions, we found that the removal of U(VI) from acidic solution was strongly dependent on pH but independent of ionic strength. The U(VI) adsorption was perfectly conformed to the pseudo-second-order kinetics and the adsorption isotherms were simulated by the Langmuir model well. A high removal capacity (qmax = 264 mg/g) for U(VI) at pH 3.5 was obtained. XPS, EXAFS analyses and DFT calculations revealed that the mechanism of uranium capture was ascribed to (i) the surface complexation by benzotriazole and carboxyl groups (providing lone pair electrons) on MBTA-GO and (ii) enhanced synergistic coordination ability of delocalized π-bond of triazole group toward U due to the transfer of electrons from graphene sheet to benzotriazole. DFT calculations further demonstrated that benzotriazole displayed stronger binding with U(VI) compared to carboxyl group due to higher binding energy of [Side/Surface-U-MBTA-GO] (79.745, 54.986 kcal/mol) than [MBTA-GO-COOH-U] (27.131 kcal/mol). This work will provide valuable insight into designing novel nitrogen-containing adsorbents for practical application in wastewater treatment.


Assuntos
Grafite/química , Triazóis/química , Urânio/química , Poluentes Radioativos da Água/química , Adsorção , Cinética , Concentração Osmolar , Óxidos/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias , Água
18.
Chemosphere ; 235: 457-469, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31272006

RESUMO

The reported presence of mixture of nanoparticles in environmental water warrants developing understanding on their aggregation and fate. This study tried to address this question and focused on understanding effects of pH (3,7 and 10), background electrolyte concentration (1 mM and 10 mM as NaCl) and nanoparticle (NP) concentration (1 and 10 mg/L) on stability of suspension containing mixture of two commonly-found metal oxide-based NP (i.e., ZnO and CuO NPs) in a 6-h study (output variables: aggregation rate constant, settling rate constant, difference in zeta potential, change of metal content in suspension and on aggregates). Two iso-electric point values were obtained: pH 3.08 and 8.33 for mixture suspension in DI (De-ionized) water and pH 5.69 and 8.65 for mixture suspension with 10 mM electrolyte concentration. Settling rate constant and aggregation rate constant values of suspension containing mixture of NPs varied between 0.02 and 0.23 NTU/(NTU-hour) and 0.0002 and 0.03 nm/s, respectively. At natural pH condition, settling rate constant and aggregation rate constant values were obtained to be 0.05 NTU/(NTU- hour) and 0.012 nm/s. The Derjaguin-Landau-Verway-Overbeek (DLVO) analyses indicated that aggregation of mixture of NPs might be happening due to combined effects of ionic layer compression, charge neutralization and van der Waals attraction. Dissolution of nanoparticles was found to be significantly affected by change in pH of suspension. Stability of mixture of nanoparticles was observed to decrease with increasing pH, ionic strength and nanoparticle concentration values. For ZnO and CuO nanoparticles, model equations were developed for predicting their (i) aggregation rate constant, (ii) settling rate constant, (iii) difference in zeta potential, (iv) percentage change of metal in suspension and (v) solid Zn fractions of mixture of nanoparticles as a function of pH, ionic strength and NP concentration. These information are useful in understanding fate of mixture of NPs in suspension as well as in settled solids in natural water bodies and in water treatment systems.


Assuntos
Cobre/química , Nanopartículas Metálicas/química , Poluentes Químicos da Água/química , Óxido de Zinco/química , Eletrólitos , Íons , Concentração Osmolar , Óxidos , Suspensões , Purificação da Água
19.
Eur J Pharm Biopharm ; 142: 307-314, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31288077

RESUMO

The influence of physiological factors on the solubility of drug compounds has been thoroughly investigated in humans. However, as these factors vary between species and since many in vivo studies are carried out in rats or mice, it has been difficult to establish sufficient in vitro in vivo relations. The aim of this study was to develop a physiologically relevant in vitro dissolution model simulating the gastrointestinal (GI) fluids of fasted rats and compare it to previously published in vitro and in vivo data. To develop the in vitro model, the pH was measured in situ in six segments of the GI tract of anesthetised rats, then the fluids from the stomach, the proximal and the distal small intestine were collected and characterized with regard to osmolality, and bile acid and phospholipid concentration. The pH and osmolality were found to increase throughout the GI tract. The bile acids and phospholipids were present in high concentrations in the proximal small intestine, and the bile acid concentration doubled in the distal part, where the phospholipid concentration decreased. Matrix-assisted laser desorption ionisation mass spectrometry imaging was applied on a cross section of the small intestine, to study which bile acids and phospholipid classes were present in the small intestine of rats. Both cholic acid, taurocholic acid and glycocholic acid were detected, and phosphatidylcholine (34:2) was found to be mainly present in the intestinal wall or mucus, whereas lysophosphatidylcholine (16:0) was also detected in the lumen. Based on these observations, biorelevant media were developed to simulate fluids in the stomach and the proximal part of the small intestine in fasted rats. The media were implemented in a two-step in vitro dissolution model, which was found to better predict the in vivo performance of furosemide, when compared to previously published in vitro and in vivo data.


Assuntos
Líquidos Corporais/metabolismo , Líquidos Corporais/fisiologia , Mucosa Gástrica/metabolismo , Intestino Delgado/metabolismo , Intestino Delgado/fisiologia , Preparações Farmacêuticas/metabolismo , Estômago/fisiologia , Animais , Humanos , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Concentração Osmolar , Ratos , Ratos Sprague-Dawley , Solubilidade
20.
Sci Total Environ ; 690: 502-510, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31301491

RESUMO

Copper oxide nanoparticles (CuO NPs), as an antimicrobial nanomaterial, have found many applications in agriculture. Ubiquitous and complex root exudates (RE) in the plant root zone motivates the determination of how specific components of RE interact with CuO NPs. This work aims to reveal the role of maize (Zea mays L.)-derived RE and their components on the aggregation and dissolution of CuO NPs in the rhizosphere. We observed that RE significantly inhibited the aggregation of CuO NPs regardless of ionic strength and electrolyte type. In the presence of RE, the CCC of CuO NPs in NaCl shifted from 30 to 125 mM and the value in CaCl2 shifted from 4 to 20 mM. Furthermore, this inhibition was correlated with molecular weight (MW) of RE fractions. Higher MW fraction (>10 kDa) reduced the aggregation most. We also discovered that RE significantly promoted the dissolution of CuO NPs and lower MW fraction (<3 kDa) RE mainly contributed to this process. Additionally, phytotoxicity of CuO NPs in the presence of RE and different fractions of RE was evaluated. The addition of 20 mg/L RE reduced the seedlings growth rate to 1.89% after 7 days exposure to 25 mg/L CuO NPs, which were significantly lower than the control group (4.82%). Notably, Cu accumulation in plant root tissues was significantly enhanced by 20 mg/L RE. This study provides useful insights into the interactions between RE and CuO NPs, which is of significance for the safe use of CuO NPs-based antimicrobial products in agricultural production.


Assuntos
Nanopartículas/química , Exsudatos de Plantas/química , Zea mays/química , Cobre , Nanopartículas/toxicidade , Concentração Osmolar , Exsudatos de Plantas/toxicidade , Raízes de Plantas/química , Rizosfera , Zea mays/toxicidade
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