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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo das intera??es do praziquantel com ciclodextrinas em sistemas multicomponentes

Souza, Jairo Sotero Nogueira de 28 November 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-02T21:45:30Z No. of bitstreams: 1 JairoSoteroNogueiraDeSouza_DISSERT.pdf: 2124011 bytes, checksum: 0d7ba6395004ada41813188b5d73116b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-07T19:30:54Z (GMT) No. of bitstreams: 1 JairoSoteroNogueiraDeSouza_DISSERT.pdf: 2124011 bytes, checksum: 0d7ba6395004ada41813188b5d73116b (MD5) / Made available in DSpace on 2017-06-07T19:30:54Z (GMT). No. of bitstreams: 1 JairoSoteroNogueiraDeSouza_DISSERT.pdf: 2124011 bytes, checksum: 0d7ba6395004ada41813188b5d73116b (MD5) 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.
2

Prepara??o e caracteriza??o de complexos multicomponentes contendo ciclodextrinas e benznidazol

Melo, Polyanne Nunes de 28 February 2013 (has links)
Made available in DSpace on 2014-12-17T14:16:33Z (GMT). No. of bitstreams: 1 PolyanneNM_DISSERT_Parcial.pdf: 770580 bytes, checksum: 39b0d43a294576d304dce8d402da84aa (MD5) 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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