Three different studies are included in this dissertation.The first chapter is a preformulation study of the anticancer drug NSC-726796. A stability-indicating HPLC method to quantify the compound and its three main degradation products was developed. This method was used to investigate its degradation kinetics and mechanism. The reaction follows first-order kinetics and appears to be base-catalyzed with a maximum stability at pH 1. The degradation products were identified as 2-(2,4-difluorophenylcarbamoyl)-3,4,5,6-tetrafluorobenzoic acid (NSC-749820), 2,4-difluoroaniline and 3,4,5,6-tetrafluorophthalic acid. The mono acid was synthesized and its structure was confirmed by single crystal crystallography. That compound is found to be more soluble and more stable than the parent drug in aqueous media.The purpose of the research reported in the second chapter is to investigate the pH-stability of an anticancer cytidine derivative and a cytidine deaminase inhibitor, individually and in combination. A stability indicating HPLC method for the quantification of 5-fluoro-2-deoxycytidine (FdCyd, NSC-48006), tetrahydrouridine (THU, NSC-112907) and their degradants was developed using a ZIC®-HILIC column. The effect of THU and FdCyd on the in vitro degradation of each other was studied as a function of pH from 1.0 to 7.4. The degradation of FdCyd appears to be first-order and acid-catalyzed. THU equilibrates with at least one of its degradants. Results show that the combination of FdCyd and THU in solution does not affect the stability of either compound. The stability and compatibility of FdCyd and THU in the solid state at 40 C/ 75% relative humidity (RH) and at ambient temperature are also evaluated.In chapter three, the effect of polarity on acid-base dissociation in ionic micellar systems is discussed. The dissociation constant of a compound (i.e., pKa) can shift when it is incorporated in or on a micelle. The magnitude of the pKa shift can be attributed to the effect of the surface potential of the micelle and the dielectric constant of the system. Currently, there is no reliable relationship to quantitate the dependence of pKa on the polarity of the drug. Experimental data for pKa of acids in cationic and anionic micelles were compiled from the literature. The increase in the pKa of weak acids upon incorporation into sodium dodecyl sulphate micellar is shown to be proportional to their ClogP values.

Preformulation studies of two naturally occurring compounds, sulforaphane and myricetin, are presented. Both compounds have shown promise as chemoprevention agents throughout the literature. Despite this evidence, minimal information is available to guide the progression of formulations designed for future drug development. The presented work describes solubility, stability, and solid-state characterization of these compounds. Additionally, a mathematical model based on the ideal solubility equation, which reasonably estimates the solubility of a hydrate is described. This model accounts for the dehydration energetics of the solute as it transforms from hydrate to anhydrous prior to melting and conversion to a hypothetical super-cooled liquid (HSL). This model will lend itself to the appreciation of the solubility differences that can exist between hydrate and anhydrous drug forms. By improving the accuracy of solubility estimation, drug development studies involving hydrates can be designed more accurately.

Candidate active pharmaceutical ingredients (APIs) are routinely tested to determine such parameters as physical stability, chemical stability, and bioavailability. Preformulation analysis of APIs does not currently attemept to determine whether they will perform to an acceptable level once they have been formulated. In practice, the APIs are subjected to extensive in vitro testing of their performance in a formulation, combined with optimisation of the formulation. This formulation testing is both time-consuming and expensive. In the field of pulmonary drug delivery from dry powder inhalers (DPIs), the API has to be aerosolized effectively in order to penetrate the lunfs and reach its deposition target. In a conventional ternary DPI fromulation, the API is combined with carrier lactose and fine lactose particles. The inter-particle forces between these three components and the bulk properties of the formulation determine the structure of the formulation and the aerolization performance of the API. In this study, physicochemical properties of salbutamol base and several of its salts were investigated both quantitatively and qualitatively. The in vitro deposition characteristics of the formulated APIs were also determined. The relationship between these parameters and the deposition was analysed to establish if a rapid preformulation screening technique could be applied to the APIs with respect to predicting the deposition performance of the formulated API. A clear relationship between the deposition of the unformulated API and the formulated API was observed that could be exploited as a screening technique.

Cápsulas gelatinosas são formas farmacêuticas empregadas para a veiculação de fármacos por via oral. Há diversas vantagens em sua utilização como a facilidade de deglutição, mascaramento do sabor e odor de fármacos e rápida disponibilização de seu conteúdo no trato gastrointestinal. Atualmente, as cápsulas são as principais formas farmacêuticas nos estabelecimentos magistrais. Como formas de liberação imediata, seu comportamento após a deglutição deve permitir a rápida liberação do(s) fármaco(s). Desta forma, fatores como a escolha correta de excipientes, observando-se a compatibilidade entre estes e o fármaco, deve ser baseada nas características físico-químicas de ambos para a obtenção de um produto eficaz. As etapas de preparo não são menos relevantes e merecem atenção, como a pesagem, a mistura e o enchimento. O objetivo deste trabalho foi discutir o tema cápsulas, salientando fatores acerca de seu emprego como forma farmacêutica, elaboração de formulações, produção e controle, visando a adequada aplicabilidade no setor magistral. / Gelatin capsules are pharmaceutical forms employed in oral drug delivery. There are many advantages on its use like easy deglutition, smell and tast masking and fast availability of its content in gastrointestinal tract. Nowadays, the capsules are the main drug delivery forms used on magistral pharmacies. As immediate drug delivery forms its behavior after deglutition should promote a fast availability of the drug(s). Thus, the right choice of the excipients, observing the compatibility between these and the drug, should be based on physicochemical caracteristhics of the compounds to achieve an adequate product. The production steps are not less relevant and deserve an appropriate attention, Iike weighing, mixture and filling. The goal of this work was discussing the theme capsules, exploring factors around its employing as drug delivery form, formulations development, production and control, seeking a suitable applicability on magistral field.

Made available in DSpace on 2014-07-29T16:11:45Z (GMT). No. of bitstreams: 1 Dissertacao Stela.pdf: 754626 bytes, checksum: 312169c0104b8d6d919af0eb6ee8cf69 (MD5) Previous issue date: 2010-03-05 / Isoflavones are flavonoids found in abundance in grains of soy (Glycine max L.) and its derivatives. These substances have estrogen like structure and weakly estrogenic action. They are used for treatment of menopause symptoms as an alternative to conventional hormone replacement therapies, because they cause fewer side effects. Soy isoflavones are amongst herbal products of great interest to obtain solid dosage forms. High assay variability of isoflavones in commercially available capsules and tablets shows the need of appropriate drug development and quality control for this herbal product. The aim of this work was drug development and quality control of soy isoflavone solid dosage forms, using standardized dry extract of soy. To evaluate the quality of the extract microbiologic and assay analysis of this drug s markers were performed. Results obtained from microbiological test did not show microbiologic contamination of the extract, as Escherichia coli, Staphylococcus aureus, Candida albicans and Aspergillus niger did not grow. To evaluate assay and dissolution percentage of both markers analytical methodology for quantification of daidzein and genistein by high performance liquid chromatography was developed, and also a method to analyze dissolution profile of the obtained tablets. Isocratic method was used for chromatographic analysis of the markers, with mobil phase of methanol with 0.1% of acetic acid, water with 0.1% of acetic acid and acetonitrile in proportion 64:32:4, flow of 0.7 mL/min and temperature of 30°C. At this condition, peaks were symmetric, had resolution lower than 2, with retention times of 3,13 and 3,72 for daidzein and genistein, respectively. Assay evaluation of the markers daidzein and genistein showed that concentrations in the extract were 27,8% and 11,1%, respectively. To accomplish preformulation study, thermal analysis and powder and granules flow evaluation were made. Six formulations of isoflavone tablets were developed, one by direct compression and five by wet granulation. Results of thermal analysis showed no possible extract interactions between tested excipients and extract. Wet granulation was the best method to obatain tablets, because it presented the best compressional properties with flow velocity between 4,5 and 6,7 s/100g and compressibility between 16,85% and 26,06%. GU3 formulation, which presented the best performance according to evaluated parameters, made by wet granulation, showed 92,66% and 92,76% of daidzein and genistein, respectively, disintegration of 15 minutes, and its flow was categorized as excellent. In analytical dissolution method development of isoflavone tablets solubility test was performed to define the best medium, and water with 3% of sodium lauryl sulfate dissolved the greatest amount of daidzein and genistein at tested temperature, 37°C, in comparison with the other medium. Other parameters defined through method development were paddle apparatus, stirring speed of 100 rpm and 900 mL of medium volume. Results showed the possibility to obtain promising solid dosage forms to deliver isoflavone, and optimized quality control methodologies to analyze raw material and finished product. / Isoflavonas são flavonóides encontrados em abundância nos grãos de soja (Glycine max L.). Essas substâncias têm estrutura semelhante ao estrógeno e possuem uma ação fracamente estrogênica. São utilizadas no tratamento dos sintomas da menopausa como alternativa às terapias de reposição hormonal convencionais, por provocarem menor número de efeitos colaterais. As isoflavonas de soja estão entre as matérias-primas vegetais com ações de interesse para obtenção de formas farmacêuticas sólidas. A alta variabilidade de teores de isoflavonas em cápsulas e comprimidos disponíveis comercialmente demonstra a necessidade de desenvolvimento farmacotécnico e controle de qualidade adequados para este fitoterápico. O objetivo deste trabalho foi o desenvolvimento analítico e farmacotécnico de formas farmacêuticas sólidas de isoflavona de soja, utilizando como matéria-prima extrato seco de soja padronizado. Para verificar a qualidade do extrato foi realizada análise microbiológica e análise do teor dos marcadores. Os resultados obtidos através do ensaio microbiológico não demonstrou contaminação microbiológica do extrato, não tendo crescimento de Escherichia coli, Staphylococcus aureus, Candida albicans e Aspergillus niger. Para avaliação do teor e da porcentagem dissolvida de ambos os marcadores foram desenvolvidas e validadas tanto metodologia analítica de quantificação de daidzeína e genisteína por cromatografia líquida de alta eficiência quanto metodologia para avaliar o perfil de dissolução dos comprimidos obtidos. Para análise cromatográfica dos marcadores foi utilizado método isocrático, com fase móvel constituída por metanol com 0,1% de ácido acético, água com 0,1% de ácido acético e acetonitrila na proporção 64:32:4 , fluxo de 0,7 mL/min e temperatura de 30ºC. Nesta condição os picos foram simétricos, tiveram resolução maior que 2, com tempos de retenção de 3,13 e 3,72 da daidzeína e genisteína, respectivamente. A avaliação do teor dos marcadores daidzeína e genisteína, demonstrou que as concentrações no extrato foram 27,8% e 11,1%, respectivamente. Em relação ao estudo de pré-formulação foi feita análise térmica e a avaliação das propriedades dos pós e grânulos. Foram desenvolvidas seis formulações de comprimidos de isoflavona, sendo uma por compressão direta e cinco por granulação úmida. Nos resultados da análise térmica não foram observadas possíveis interações dos excipientes com o extrato. O melhor método de obtenção dos comprimidos foi por granulação úmida, pois apresentou melhores propriedades compressionais com velocidade de escoamento variando entre 4,5 e 6,7 s/100g e compressibilidade entre 16,85% e 26,06%. A formulação por granulação úmida 3 foi a que apresentou melhor desempenho segundo os parâmetros analisados, apresentando teor de 92,66% e 92,76% de daidzeína e genisteína, respectivamente, desintegração de 15 minutos, e seu fluxo foi caracterizado como excelente. No desenvolvimento do método analítico para dissolução dos comprimidos de isoflavona foi feito o teste de solubilidade para definir o melhor meio, sendo o meio água com 3% de lauril sulfato de sódio o que dissolveu maior quantidade de daidzeína e genisteína na temperatura de 37ºC em comparação com os outros meios. Os demais parâmetros definidos através do desenvolvimento do método foram aparato pá, velocidade de rotação de 100 rpm e 900 mL de volume de meio. Os resultados mostraram a possibilidade de obtenção de formas farmacêuticas sólidas promissoras para veiculação de isoflavona, além de metodologias otimizadas para controle de qualidade para análise da matéria-prima e do produto acabado.

Cápsulas gelatinosas são formas farmacêuticas empregadas para a veiculação de fármacos por via oral. Há diversas vantagens em sua utilização como a facilidade de deglutição, mascaramento do sabor e odor de fármacos e rápida disponibilização de seu conteúdo no trato gastrointestinal. Atualmente, as cápsulas são as principais formas farmacêuticas nos estabelecimentos magistrais. Como formas de liberação imediata, seu comportamento após a deglutição deve permitir a rápida liberação do(s) fármaco(s). Desta forma, fatores como a escolha correta de excipientes, observando-se a compatibilidade entre estes e o fármaco, deve ser baseada nas características físico-químicas de ambos para a obtenção de um produto eficaz. As etapas de preparo não são menos relevantes e merecem atenção, como a pesagem, a mistura e o enchimento. O objetivo deste trabalho foi discutir o tema cápsulas, salientando fatores acerca de seu emprego como forma farmacêutica, elaboração de formulações, produção e controle, visando a adequada aplicabilidade no setor magistral. / Gelatin capsules are pharmaceutical forms employed in oral drug delivery. There are many advantages on its use like easy deglutition, smell and tast masking and fast availability of its content in gastrointestinal tract. Nowadays, the capsules are the main drug delivery forms used on magistral pharmacies. As immediate drug delivery forms its behavior after deglutition should promote a fast availability of the drug(s). Thus, the right choice of the excipients, observing the compatibility between these and the drug, should be based on physicochemical caracteristhics of the compounds to achieve an adequate product. The production steps are not less relevant and deserve an appropriate attention, Iike weighing, mixture and filling. The goal of this work was discussing the theme capsules, exploring factors around its employing as drug delivery form, formulations development, production and control, seeking a suitable applicability on magistral field.