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Estudo das intera??es do praziquantel com ciclodextrinas em sistemas multicomponentesSouza, Jairo Sotero Nogueira de 28 November 2016 (has links)
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Previous issue date: 2016-11-28 / A utiliza??o de ciclodextrinas para aumentar a solubilidade de f?rmacos em solu??o aquosa tem sido bastante estudada. No presente estudo, o mecanismo de intera??o do praziquantel (PZQ) com a beta-ciclodextrina e com a hidroxipropil-beta-ciclodextrina na presen?a dos co-solventes trietanolamina (TEA) e a N-metilpirrolidona (NMP) foi realizado com o objetivo do aumento da solubilidade do praziquantel. Atrav?s dos diagramas de solubilidade e dos diagramas de Job?s Plot foi poss?vel observar a forma??o de complexos sol?veis com estequiometria 1:1. A presen?a dos co-solventes TEA e NMP diminuiu a estabilidade e solubilidade dos complexos formados, no entanto atrav?s dos estudos de modelagem molecular foi mostrado que este efeito pode facilitar a sa?da do f?rmaco da cavidade e, consequentemente, beneficiar a absor??o do f?rmaco. Os resultados mostraram-se elucidativos e bastantes promissores na obten??o futura de complexos que possam ser utilizados para melhor biodisponibilidade do praziquantel. / The use of cyclodextrin (CD) to enhace the praziquantel (PZQ) water solubility has been widely studied in the literature. In this present paper, the interaction has not yet studied between the PZQ and both the beta-cyclodextrin (?-CD) and hydroxyl-propyl-cyclodextrin (HP-?-CD) or its association with the solvents triethanolamine (TEA) and N-methyl-pyrrolidone (NMP) was carefully conducted with the purpose to enhance the water solubility of the PZQ. The solubility diagrams and job?s plot diagrams showed that water soluble complexes were formed with 1:1 stoichiometry. The association of the complexes with the TEA and NMP diminished considerably the complex stability and its solubility. However, throught the molecular modeling study it was showed that this effect may be beneficial for the output of the drug from the CD cavity, and consequently to benefit the drug absorption. The results showed up adequately enlightening to propose that these systems can be investigated to enhance the PZQ bioavailability.
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Prepara??o e caracteriza??o de complexos multicomponentes contendo ciclodextrinas e benznidazolMelo, Polyanne Nunes de 28 February 2013 (has links)
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Previous issue date: 2013-02-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The benznidazole (BNZ) is the only alternative for Chagas disease
treatment in Brazil. This drug has low solubility, which restricts its dissolution
rate. Thus, the present work aimed to study the BNZ interactions in binary
systems with beta cyclodextrin (?-CD) and hydroxypropyl-beta cyclodextrin
(HP-?-CD), in order to increase the apparent aqueous solubility of drug. The
influence of seven hydrophilic polymers, triethanolamine (TEA) and 1-methyl-2-
pyrrolidone (NMP) in benznidazole apparent aqueous solubility, as well as the
formation of inclusion complexes was also investigated. The interactions in
solution were predicted and investigated using phase solubility diagram
methodology, nuclear magnetic resonance of protons (RMN) and molecular
modeling. Complexes were obtained in solid phase by spray drying and
physicochemical characterization included the UV-Vis spectrophotometric
spectroscopy in the infrared region, scanning electron microscopy, X-ray
diffraction and dissolution drug test from the different systems. The increment
on apparent aqueous solubility of drug was achieved with a linear type (AL) in
presence of both cyclodextrins at different pH values. The hydrophilic polymers
and 1-methyl-2-pyrrolidone contributes to the formation of inclusion complexes,
while the triethanolamine decreased the complex stability constant (Kc). The
log-linear model applied for solubility diagrams revealed that both
triethanolamine and 1-methyl-2-pyrrolidone showed an action cosolvent (both
solvents) and complexing (1-methyl-2-pyrrolidone). The best results were
obtained with complexes involving 1-methyl-2-pyrrolidone and hydroxypropylbeta-
cyclodextrin, with an increased of benznidazole solubility in 27.9 and 9.4
times, respectively. The complexes effectiveness was proven by dissolution
tests, in which the ternary complexes and physical mixtures involving 1-methyl-
2-pyrrolidone and both cyclodextrins investigated showed better results,
showing the potential use as novel pharmaceutical ingredient, that leads to
increased benznidazole bioavailability / A doen?a de Chagas tem como ?nica alternativa para tratamento, no Brasil, o
benznidazol (BNZ). Este f?rmaco possui baixa solubilidade, o que restringe sua
velocidade de dissolu??o. Diante disto, o presente trabalho teve como objetivo
o estudo das intera??es do BNZ em sistemas bin?rios com a beta-ciclodextrina
(?-CD) e a hidroxipropil-beta-ciclodextrina (HP-?-CD), com o intuito de
aumentar a solubilidade aquosa do f?rmaco. A influ?ncia de sete pol?meros
hidrof?licos, da trietanolamina (TEA) e da metil-1-pirrolidona-2 (NMP) na
solubilidade aquosa aparente do benznidazol, assim como na forma??o dos
complexos de inclus?o, tamb?m foi investigada. As intera??es em solu??o
foram previstas e investigadas usando os diagramas de solubilidade de fases,
espectroscopia de ressonancia magn?tica nuclear de pr?tons (RMN) e
modelagem molecular. Diferentes complexos foram obtidos em fase s?lida por
secagem por atomiza??o em aparelho de spray dryer e a caracteriza??o
f?sico-qu?mica destes incluiu a espectrofotometria UV-Vis, a espectroscopia na
regi?o do infravermelho, a microscopia eletr?nica de varredura, a difra??o de
raios-X e os ensaios de dissolu??o do f?rmaco a partir das diferentes amostras.
O aumento da solubilidade aquosa aparente do f?rmaco foi alcan?ada de forma
linear (perfil AL) na presen?a de ambas as ciclodextrinas em diferentes valores
de pH. A presen?a dos pol?meros hidrof?licos e da metil-1-pirrolidona-2 contribui
para a estabiliza??o dos complexos formados, enquanto a trietanolamina
diminuiu a constante de estabilidade (Kc) dos complexos formados. O modelo
do log linear aplicado aos diagramas de solubilidade revelou que a
trietanolamina e a metil-1-pirrolidona-2 mostraram uma a??o cossolvente
(ambos solventes) e complexante (metil-1-pirrolidona-2). Os melhores
resultados foram obtidos com os complexos envolvendo a metil-1-pirrolidona-2
e a hidroxipropil-beta-ciclodextrina, com um aumento de solubilidade do
f?rmaco em 27,9 e 9,4 vezes, respectivamente. A efic?cia dos complexos foi
comprovada pelos ensaios de dissolu??o, nos quais os complexos tern?rios e
misturas f?sicas envolvendo a metil-1-pirrolidona-2 e as ciclodextrinas
investigadas apresentaram os melhores resultados, demonstrando a
possibilidade de uso como um novo insumo farmac?utico, que leve ao aumento
da biodisponibilidade do benznidazol / 2020-01-01
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