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

Poorly water-soluble drugs (PWSDs), to date, require advanced formulation techniques to improve solubility and achieve the required plasma concentration to show a therapeutic effect when orally administered. Lipid-based formulations (LBFs) are an enabling strategy that is being used to improve the oral delivery of PWSDs. The aim of this study was to investigate the effect of lipid-based formulation, Type IIIA-LC, on the solubilization patterns of PWSDs, namely, carvedilol and felodipine. Solubility studies, for both drugs, were performed with LBF dispersed in -1) dog intestinal fluid (DIF), and 2) water, to identify and compare the extent of solubility in different matrices, and in silico to identify interesting patterns with any correlations in experimental and computational data. Solubility studies showed that carvedilol had better solubility in LBF when compared to felodipine. Computational studies showed that both drugs solubilized in the colloid in both digested and undigested states. Effect of drug loading had no significant difference on the solubilization patterns of both drugs. The maximum drug loading done was for 100 molecules though there is the possibility of the colloid having a higher capacity. Digestion did not seem to have a significant effect on the distribution of both drugs. In vitro and in silico data were in qualitative agreement and therefore, this computational model can be further used to study the specific processes causing solubilization, improvement, and development of new LBFs.