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Previous issue date: 2013-05-22 / Clays are natural materials that have great potential for use as excipients for solid dosage forms. Palygorskite is a type of clay that has hydrophilic properties as well as a large surface area, which could contribute to the dissolution of drugs. Thus, the present study aims to evaluate the use of palygorskite clay, from Piaui (Northeast region of Brazil), as a pharmaceutical excipient for solid dosage forms, using rifampicin and isoniazid as the model drugs. The former is a poorly soluble drug often associated with isoniazid for tuberculosis treatment. Palygorskite was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and specific surface area (BET). The rheological and technological properties of palygorskite were determined and compared to those of talc, magnesium stearate and Aersosil 200. Mixtures between drugs and palygorskite were analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TG) combined with thermal analysis (DTA) and Fourier Transform Infrared Spectroscopy (FT-IR), where the results were compared with those of the individual compounds. In addition, dissolution studies of solid dispersions and capsules containing the drugs, mixed with either palygorskite or a mixture of talc and magnesium stearate, were performed. The results showed that palygorskite has small particles with a high surface area. Its rheological characteristics were better than those of others commonly used glidants and lubricants. There was no interaction between palygorskite and the drugs (rifampicin and isoniazid). Among the dispersions studied, the mixture with palygorskite (5%) showed the highest drug dissolution when compared to other excipients. The dissolution of the rifampicin capsules containing palygosrkite was faster in higher concentrations. However, these differences were statistically different only in the first minutes of the dissolution experiment. The dissolution profile of isoniazid was also statistically different on the initial part of the experiment. The formulations prepared with isoniazid and palygorskite showed higher drug dissolution, but it was in descending order of concentration. According to these results, the palygorskite clay used in this study has great potential for application as an excipient for solid dosage forms / Argilas s?o materiais naturais, com baixa toxicidade e com potencial para atuar como excipiente. A atapulgita ? uma argila com caracter?stica hidrof?lica e grande ?rea superficial. Assim, este trabalho tem por objetivo avaliar o uso da atapulgita como excipiente farmac?utico em formas s?lidas, utilizando a rifampicina e a isoniazida como f?rmacos-modelo. A atapulgita ? proveniente do Estado do Piau?, Nordeste, Brasil. A rifampicina ? um f?rmaco de baixa solubilidade frequentemente associado ? isoniazida para o tratamento da tuberculose. Inicialmente a atapulgita foi caracterizada por difra??o de raios-X (DRX), fluoresc?ncia de raios-X (FRX), an?lise granulom?trica, microscopia eletr?nica de transmiss?o (MET) e varredura (MEV) e determina??o da ?rea de superf?cie espec?fica (BET). As propriedades reol?gicas e tecnol?gicas da argila foram determinadas e comparadas ao talco, estearato de magn?sio e Aerosil 200. Misturas entre os f?rmacos e a argila (1:1, 1:2 e 1:1:1), bem como os materiais isolados, foram avaliadas por calorimetria explorat?ria diferencial (DSC), an?lise termogravim?trica (TG) combinada ? an?lise t?rmica diferencial (DTA) e espectroscopia na regi?o do infravermelho com transformada de Fourier (FT- IR). Estudos de dissolu??o de dispers?es s?lidas e de c?psulas contendo os f?rmacos e a atapulgita foram realizados e comparados ao emprego de talco e estearato de magn?sio. Os resultados mostraram que a atapulgita apresenta part?culas pequenas, com grande ?rea de superf?cie. Apresentou boas caracter?sticas reol?gicas quando comparada ao demais reguladores de fluxo. N?o foi evidenciada intera??o com os f?rmacos testados. Entre as dispers?es, as misturas com atapulgita (5%) mostraram maior dissolu??o dos f?rmacos em rela??o a outros excipientes . O perfil de dissolu??o da rifampicina foi superior na formula??o de c?psula contendo atapulgita em maior concentra??o, sendo estatisticamente diferente nos primeiros minutos. O perfil de dissolu??o da isoniazida tamb?m se mostrou estatisticamente diferente nos primeiros minutos, sendo as formula??es com atapulgita as que apresentaram maior dissolu??o do f?rmaco, por?m em ordem decrescente de concentra??o. A argila atapulgita apresenta, portanto, potencial para aplica??o como excipiente em formas farmac?uticas s?lidas
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/13492 |
| Date | 22 May 2013 |
| Creators | Soares, Daiane dos Santos |
| Contributors | CPF:13138863434, http://lattes.cnpq.br/4452581275123481, Silva J?nior, Arn?bio Ant?nio, CPF:00840406452, http://lattes.cnpq.br/2593509584288129, Moura, T?lio Fl?vio Accioly Lima e |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncias Farmac?uticas, UFRN, BR, Bioan?lises e Medicamentos |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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