Consulta: subjectFacets:"Controlled release"
Registros recuperados: 9
Data/hora: 11/06/2024 09:01:12

Atrazine persistence applied as commercial and xerogel formulations in oxisol
Provedor de dados: 87
Autores: Trezzi,M.M.; Marchesan,E.D.; Vidal,R.A.; Xavier,E.; Dick,D.P.
The intensive use of pesticides have contaminated the soil and groundwater. The application of herbicides as controlled release formulations may reduce the environmental damage related to their use because it may optimize the efficiency of the active ingredient and reducing thus the recommended dose. The objective of this study was to evaluate the persistence of the herbicide atrazine applied as commercial formulation (COM) and as controlled release formulation (xerogel - XER) in Oxisol. The experimental design used was split-plot randomized-blocks with four replications, in a (2 x 6) + 1 arrangement. The two formulations (COM and XER) were assigned to main plots and different atrazine concentrations (0, 3.200, 3.600, 4.200, 5.400 and 8.000 g atrazine...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Residual herbicides; Controlled release; Half-life.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582013000300018

ATRAZINE EFFICIENCY IN AN ANDISOL AS AFFECTED BY CLAYS AND NANOCLAYS IN ETHYLCELLULOSE CONTROLLED RELEASE FORMULATIONS
Provedor de dados: 127
Autores: Cea,M; Cartes,P; Palma,G; Mora,M.L.
Atrazine, a herbicide used for the control of broadleaf weeds of different crops, was incorporated in ethylcellulose controlled release formulations (CRFs) by using the solvent evaporation technique. Allophanic clays and nanoclays were incorporated as matrix modifying agents. The formulations were characterized by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), and their behavior was determined in aqueous phase. Dissipation studies and soil columns experiments with CRFs were also carried out, and compared with commercial formulations (CFs). In addition, a short-term bioassay was performed to evaluate the effect of CRFs and CFs on the emergence and growth of field mustard (Brassica campestris L.) under greenhouse conditions. The matrix...
Tipo: Journal article
Palavras-chave: Atrazine; Natural clays and nanoclays; Controlled release; Soil; Herbicidal activity.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912010000100007

Biodegradable oil-based polymeric coatings on urea fertilizer: N release kinetic transformations of urea in soil
Provedor de dados: 63
Autores: Bortoletto-Santos,Ricardo; Guimarães,Gelton Geraldo Fernandes; Roncato Junior,Vanderlei; Cruz,Diego Fernandes da; Polito,Wagner Luiz; Ribeiro,Caue.
ABSTRACT: Polymer coatings are used to control the rate of release of plant available nutrients from fertilizers as well as to reduce nutrient losses such as ammonia (NH3) volatilization. Although the literature presents several examples of materials used to coat urea, little is known about nitrogen (N) release properties such as the mechanism involved and phenomena (e.g., pore opening) in the polymer coating. Thus, this study investigated urea release from polyurethane (PU) derived from two renewable raw materials (castor oil and soybean oil), to explain how the oil structure and coating microstructure influence release and urea-N dynamics in soil. The results demonstrated that the profile of urea release and the urea-N mineralization in the soil could be...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Polyurethane; Controlled release; Plant nutrition; Soil fertility; Nitrogen.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000101402

Preparation of pellets containing highly soluble drug by extrusion/spheronisation and coating with Kollicoat® SR 30D
Provedor de dados: 52
Autores: Andreazza,Itamar Francisco; Ferraz,Humberto Gomes.
The aim of this study was to prepare and evaluate the pellets, containing a highly soluble drug (ascorbic acid), by the extrusion-spheronization process and coated with a release controlling polymer. The coating (undertaken in a fluid bed) was applied to three batches of the pellets with a dispersion of Kollicoat® SR 30 D, with each batch of pellets receiving a different level of polymer (5.07; 8.26 and 10.35%). The coated pellets were evaluated for sphericity by imaging analysis and comparative dissolution profile with a product commercially available in Brazil. All of the evaluated samples presented adequate physical properties and the dissolution profile of those coated with 5.07% of polymer proved to be similar to that of the commercially available...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coating; Pellets; Extrusion spheronization; Controlled release.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000200013

Slow-release urea in supplement fed to beef steers
Provedor de dados: 52
Autores: Gonçalves,Ana Paula; Nascimento,Carolina Fernanda Moysés do; Ferreira,Fernanda Altieri; Gomes,Rodrigo da Costa; Manella,Marcelo de Queiroz; Marino,Carolina Tobias; Demarchi,João José Assumpção de Abreu; Rodrigues,Paulo Henrique Mazza.
Replacing regular urea (RU) by slow-release urea (SRU) at two levels of non-protein nitrogen (NPN) in concentrate, offered with low-quality roughage, was evaluated in beef steers on dry matter intake (DMI), ruminal fermentation parameters, plasma urea nitrogen (PUN), total tract apparent digestibility of diets and in situ degradability of nitrogen sources. Eight ruminally cannulated steers were allocated into two 4x4 Latin squares, totalizing four treatments: 40 NPN/0 SRU: 40% of concentrate crude protein (CP) as NPN, resulting from 0% of SRU and 100% of RU; 40 NPN/50 SRU: 40% of concentrate CP as NPN, resulting from 50% of SRU and 50% of RU; 40 NPN/100 SRU: 40% of concentrate CP as NPN, resulting from 100% of SRU and 0% of RU; 80 NPN/100 SRU: 80% of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Controlled release; Feed intake; Non-protein nitrogen; Short chain fatty acids.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132015000100022

Hydroxypropylcellulose controlled release tablet matrix prepared by wet granulation: effect of powder properties and polymer composition
Provedor de dados: 52
Autores: Teixeira,Antonio Zenon Antunes.
The aim of this study was to attain 100% drug release of caffeine after 24 h from hydroxypropylcellulose (HPC) tablet matrices and to investigate the effect of co-excipient. Physical properties of the powders were evaluated and suggested for a wet granulation process. The tablet containing caffeine was formulated by different weight ratios of hydrophilic polymers. The results of polymer evaluation confirmed that the increase of HPC level with the same drug content significantly decreased the rate of drug release. The presence of co-polymer excipients carboxymethylcellulose (CMC) and polyvinylpyrrolidone (PVP) in the tablet matrix was also investigated. The release rate was also controlled by low levels of CMC (&lt;10%) while PVP did not show any...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Controlled release; Caffeine; Hydroxypropylcellulose (HPC); Polyvinylpyrrolidone (PVP); Carboxymethylcellulose (CMC); Lactose.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000100021

A pH-responsive drug delivery matrix from an interpolyelectrolyte complex: preparation and pharmacotechnical properties
Provedor de dados: 60
Autores: Montaña,Jorge Andrés; Perez,León Darío; Baena,Yolima.
ABSTRACT Interpolyelectrolyte complexes, which constitute a type of polymeric material obtained through the self-assembly of oppositely charged polymers, exhibit interesting properties for use in the design of smart matrices for drug delivery. In the present study, a stoichiometric interpolyelectrolyte complex (SIPEC) composed of Eudragit E® and Eudragit® L100 was obtained at pH 6.0 and characterized and evaluated as a hydrophilic matrix for dexibuprofen. The formation of a SIPEC was monitored by ζ-potential measurements and characterized using infrared spectroscopy, thermal analysis, and scanning electron microscopy. The results indicated that a SIPEC obtained under these conditions can be used as a matrix for controlling the release of dexibuprofen and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Interpolyelectrolyte complex; Pharmacotechnical properties; Dexibuprofen; Controlled release; Hydrophillic matrix.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502018000200620

Microencapsulation: concepts, mechanisms, methods and some applications in food technology
Provedor de dados: 65
Autores: Silva,Pablo Teixeira da; Fries,Leadir Lucy Martins; Menezes,Cristiano Ragagnin de; Holkem,Augusto Tasch; Schwan,Carla Luisa; Wigmann,Évelin Francine; Bastos,Juliana de Oliveira; Silva,Cristiane de Bona da.
Microencapsulation is a process in which active substances are coated by extremely small capsules. It is a new technology that has been used in the cosmetics industry as well as in the pharmaceutical, agrochemical and food industries, being used in flavors, acids, oils, vitamins, microorganisms, among others. The success of this technology is due to the correct choice of the wall material, the core release form and the encapsulation method. Therefore, in this review, some relevant microencapsulation aspects, such as the capsule, wall material, core release forms, encapsulation methods and their use in food technology will be briefly discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Microcapsules; Microencapsulation; Controlled release.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782014000701304

Microencapsulation of probiotics using sodium alginate
Provedor de dados: 65
Autores: Etchepare,Mariana de Araújo; Barin,Juliano Smanioto; Cichoski,Alexandre José; Jacob-Lopes,Eduardo; Wagner,Roger; Fries,Leadir Lucy Martins; Menezes,Cristiano Ragagnin de.
The consumption of probiotics is constantly growing due to the numerous benefits conferred on the health of consumers. In this context, Microencapsulation is a technology that favors the viability of probiotic cultures in food products, mainly by the properties of protection against adverse environmental conditions and controlled release. Currently there are different procedures for microencapsulation using polymers of various types of natural and synthetic origin. The use of sodium alginate polymers is one of the largest potential application in the encapsulation of probiotics because of their versatility, biocompatibility and toxicity exemption. The aim of this review is to present viable encapsulation techniques of probiotics with alginate, emphasizing...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alginate; Controlled release; Microencapsulation; Probiotics.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015000701319