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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

Dissolving the Rocks : Solubility Enhancement of Active Pharmaceutical Ingredients using Mesoporous Silica

Xia, Xin January 2014 (has links)
Poor aqueous solubility is one of the greatest barriers for new drug candidates to enter toxicology studies, let alone clinical trials. This thesis focuses on contributing to solving this problem, evaluating the oral toxicity of mesoporous silica particles, and enhancing the apparent solubility and bioavailability of active pharmaceutical ingredients in vitro and in vivo using mesoporous silica particles. Toxicological studies in rats showed that two types of mesoporous silica particles given by oral administration were well tolerated without showing clinical signs of toxicity. Solubility enhancement, including in vivo bioavailability and in vitro intracellular activity, has been evaluated for selected drug compounds. Mesoporous silica was shown to effectively increase drug solubility by stabilizing the amorphous state of APIs, such as itraconazole (anti-fungal), dasatinib (anti-cancer), atazanavir (anti-HIV) and PA-824 (anti-tuberculosis). Itraconazole was successfully loaded into a variety of porous silica materials showing a distinct improvement in the dissolution properties in comparison to non-porous silica materials (and the free drug). Microporosity in SBA-15 particles has advantages in stabilizing the supersaturation state of dasatinib. Small pore sizes show better confinement of atazanavir, contributing to a higher dissolution of the drug compound. In the in vivo animal studies, NFM-1 loaded with atazanavir shows a four-fold increase in bioavailability compared to free crystalline atazanavir. PA-824 has a higher dissolution rate and solubility after loading into AMS-6 mesoporous particles. The loaded particles show similar antibacterial activity as the free PA-824. This thesis aims at highlighting some of the important factors enabling the selection of adequate mesoporous structures to enhance the pharmacokinetic profile of poorly water-soluble compounds, and preparing the scientific framework for uncovering the effects of drug confinement within mesopores of varying structural properties. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted. Paper 5: Submitted.</p>
2

Protection Mechanisms of Excipients on Lactate Dehydrogenase during Freeze-Thawing and Lyophilization

Mi, Yanli. January 2002 (has links)
Thesis (Ph. D.)--University of Tennessee, Memphis, 2002.
3

Aplicação de métodos termo-analíticos e espectroscóspicos na avaliação do comportamento do fármaco isoniazida frente a adjuvantes tecnológicos / Application of thermo-analytical and spectroscopical methods on the evaluation of the behavior of isoniazid and pharmaceutical excipients

Velásquez Armijo, Cristián Jesús January 2003 (has links)
Os métodos termo-analíticos são ferramentas úteis na avaliação da compatibilidade entre fármacos e adjuvantes, com destaque à calorimetria exploratória diferencial. Neste trabalho foram avaliados a compatibilidade e o comportamento térmico entre a isoniazida e adjuvantes tecnológicos primários usualmente empregados em formas farmacêuticas sólidas. A compatibilidade foi examinada por meio da preparação de misturas físicas binárias do tipo fármaco/adjuvante. Foi investigada também a influência da granulação por via úmida e do processo de compactação para as misturas de isoniazida e adjuvantes com função de material de enchimento e carga e deslizante. A isoniazida apresentou um comportamento térmico não encontrado na literatura. Os adjuvantes avaliados foram: ácido esteárico, amido, celulose microcristalina, crospovidona, croscarmelose sódica, dióxido de silício coloidal estearato de magnésio, glicolato de amido sódico, hipromelose, lactose, manitol, polidona e talco. Para as misturas físicas, a maioria dos adjuvantes mostrou-se compatível com o fármaco em questão. Foram verificadas interações com o ácido esteárico, o glicolato de amido sódico, a lactose, o manitol e a povidona. A isoniazida mostrou a formação de uma mistura eutética com o manitol e de interação química com a lactose. A agregação por via úmida e o processo de compactação não mostraram influências adicionais na compatibilidade das misturas avaliadas. Os resultados observados foram confirmados por métodos não-térmicos como difratometria de raios X, espectroscopia de infravermelho e ressonância nuclear magnética. / Thermo-analytical methods, and specially Differential Scanning Calorimetry, are useful support for the evaluation of compatibility between drug substances and pharmaceutical excipients. In this work were studied the compatibility and the thermal behavior of isoniazid and pharmaceutical excipients, commonly used for the formulation of solid dosage forms. Colloidal silicon dioxide, corn starch, crospovidone, hypromellose, lactose, magnesium stearate, mannitol, microcrystalline cellulose, povidone, sodium croscarmellose, sodium starch glycolate, stearic acid and talc were the excipients employed in these experiments. The compatibility was analyzed testing binary physical drug/excipient admixtures. The effect of wet granulation and compression was also investigated, in this case especially between isoniazid, fillers and lubricant. For almost all excipients no incompatibilities with isoniazid were observed. Interactions were detected when the drug substance was added to stearic acid, sodium starch glycolate, lactose, mannitol and povidone. Isoniazid formed a euthetic mixture with mannitol, whereas a possible chemical reaction occurred between isoniazid and lactose. Wet granulation and compaction of the tested admixtures did not affect the results observed above. These observations were confirmed by non-thermal techniques, such as X-Ray diffractometry, infrared spectroscopy and nuclear magnetic resonance.
4

Granulation humide des poudres cohésives : rhéologie, mécanismes de croissance et tenue mécanique des granules / Wet granulation of cohesive powders : Rheology, growth mechanisms and granule strength

Chitu, Toma-Mihai 10 December 2009 (has links)
Cette étude est dédiée à la compréhension du processus de granulation humide en mélangeurs à haut taux de cisaillement. Une étude systémique et méthodologique a été menée permettant l'investigation de l'influence des paramètres opératoires, de la technologie employée et des propriétés physico-chimiques des matières premières. Cette investigation est réalisé a travers des techniques de caractérisation morphologiques, rhéologiques et mécaniques. En reliant les courbes de couple enregistrés lors de la granulation humide à la cinétique de croissance des granules, aux caractérisations microscopiques et aux propriétés mécaniques des granules la prédiction du comportement lors de la granulation devient possible. La caractérisation des propriétés mécaniques des granules a été étudié à deux échelles: à l'échelle du milieu humide la consistance a été caractérisé par un rheometre à torque et à l'échelle de l'agglomérat sec la résistance mécanique a été caractérisé par des mesures de compression directe des grains individuelles. Cette approche permet d'avoir des informations complémentaires permettant de mieux décrire l'évolution des courbes de couple dépendantes de propriétés de la masse humide et la compétition entre les forces interfaciales et visqueuses conditionnant la qualité des grains secs résultés. Les paramètres investigués par cette approche sont l'effet du taux de remplissage du réacteur, l'effet de la vitesse d'agitation, de la présence et de la conception de l'émotteur, de la conception du réacteur employé, des propriétés physico-chimiques de la solution liante et des propriétés des mélanges binaires des poudres hydro-solubles / hydro-insolubles. / This study is dedicated to the understanding of the wet granulation process in high shear mixers. A systematic study has been carried out that allows the investigation of the influence of operating conditions, technology and physico-chemical properties of the starting materials. This investigation is achieved by morphological, rheological and mechanical characterization methods. By linking recorded torque curves during the granulation process to granule growth kinetics, microscope characterizations and to the end-granule properties granulation outcome prediction becomes possible. The characterization of the mechanical properties has been done at two scales: at the granule bed scale the bulk wet mass consistency has been determined on a mixer torque rheometer, at the granule scale single dry granule direct compression tests were carried out. This approach gives complementary information allowing better description of the torque curves directly related to the wet mass properties and the competition between static and viscous forces conditioning the dry end granule quality. The factors investigated in this study are: the effect of fill ratio, impeller speed, chopper presence and design, mixer design, binder physico-chemical properties and formulation properties for binary water-soluble / water insoluble powder mixtures.
5

Aplicação de métodos termo-analíticos e espectroscóspicos na avaliação do comportamento do fármaco isoniazida frente a adjuvantes tecnológicos / Application of thermo-analytical and spectroscopical methods on the evaluation of the behavior of isoniazid and pharmaceutical excipients

Velásquez Armijo, Cristián Jesús January 2003 (has links)
Os métodos termo-analíticos são ferramentas úteis na avaliação da compatibilidade entre fármacos e adjuvantes, com destaque à calorimetria exploratória diferencial. Neste trabalho foram avaliados a compatibilidade e o comportamento térmico entre a isoniazida e adjuvantes tecnológicos primários usualmente empregados em formas farmacêuticas sólidas. A compatibilidade foi examinada por meio da preparação de misturas físicas binárias do tipo fármaco/adjuvante. Foi investigada também a influência da granulação por via úmida e do processo de compactação para as misturas de isoniazida e adjuvantes com função de material de enchimento e carga e deslizante. A isoniazida apresentou um comportamento térmico não encontrado na literatura. Os adjuvantes avaliados foram: ácido esteárico, amido, celulose microcristalina, crospovidona, croscarmelose sódica, dióxido de silício coloidal estearato de magnésio, glicolato de amido sódico, hipromelose, lactose, manitol, polidona e talco. Para as misturas físicas, a maioria dos adjuvantes mostrou-se compatível com o fármaco em questão. Foram verificadas interações com o ácido esteárico, o glicolato de amido sódico, a lactose, o manitol e a povidona. A isoniazida mostrou a formação de uma mistura eutética com o manitol e de interação química com a lactose. A agregação por via úmida e o processo de compactação não mostraram influências adicionais na compatibilidade das misturas avaliadas. Os resultados observados foram confirmados por métodos não-térmicos como difratometria de raios X, espectroscopia de infravermelho e ressonância nuclear magnética. / Thermo-analytical methods, and specially Differential Scanning Calorimetry, are useful support for the evaluation of compatibility between drug substances and pharmaceutical excipients. In this work were studied the compatibility and the thermal behavior of isoniazid and pharmaceutical excipients, commonly used for the formulation of solid dosage forms. Colloidal silicon dioxide, corn starch, crospovidone, hypromellose, lactose, magnesium stearate, mannitol, microcrystalline cellulose, povidone, sodium croscarmellose, sodium starch glycolate, stearic acid and talc were the excipients employed in these experiments. The compatibility was analyzed testing binary physical drug/excipient admixtures. The effect of wet granulation and compression was also investigated, in this case especially between isoniazid, fillers and lubricant. For almost all excipients no incompatibilities with isoniazid were observed. Interactions were detected when the drug substance was added to stearic acid, sodium starch glycolate, lactose, mannitol and povidone. Isoniazid formed a euthetic mixture with mannitol, whereas a possible chemical reaction occurred between isoniazid and lactose. Wet granulation and compaction of the tested admixtures did not affect the results observed above. These observations were confirmed by non-thermal techniques, such as X-Ray diffractometry, infrared spectroscopy and nuclear magnetic resonance.
6

Aplicação de métodos termo-analíticos e espectroscóspicos na avaliação do comportamento do fármaco isoniazida frente a adjuvantes tecnológicos / Application of thermo-analytical and spectroscopical methods on the evaluation of the behavior of isoniazid and pharmaceutical excipients

Velásquez Armijo, Cristián Jesús January 2003 (has links)
Os métodos termo-analíticos são ferramentas úteis na avaliação da compatibilidade entre fármacos e adjuvantes, com destaque à calorimetria exploratória diferencial. Neste trabalho foram avaliados a compatibilidade e o comportamento térmico entre a isoniazida e adjuvantes tecnológicos primários usualmente empregados em formas farmacêuticas sólidas. A compatibilidade foi examinada por meio da preparação de misturas físicas binárias do tipo fármaco/adjuvante. Foi investigada também a influência da granulação por via úmida e do processo de compactação para as misturas de isoniazida e adjuvantes com função de material de enchimento e carga e deslizante. A isoniazida apresentou um comportamento térmico não encontrado na literatura. Os adjuvantes avaliados foram: ácido esteárico, amido, celulose microcristalina, crospovidona, croscarmelose sódica, dióxido de silício coloidal estearato de magnésio, glicolato de amido sódico, hipromelose, lactose, manitol, polidona e talco. Para as misturas físicas, a maioria dos adjuvantes mostrou-se compatível com o fármaco em questão. Foram verificadas interações com o ácido esteárico, o glicolato de amido sódico, a lactose, o manitol e a povidona. A isoniazida mostrou a formação de uma mistura eutética com o manitol e de interação química com a lactose. A agregação por via úmida e o processo de compactação não mostraram influências adicionais na compatibilidade das misturas avaliadas. Os resultados observados foram confirmados por métodos não-térmicos como difratometria de raios X, espectroscopia de infravermelho e ressonância nuclear magnética. / Thermo-analytical methods, and specially Differential Scanning Calorimetry, are useful support for the evaluation of compatibility between drug substances and pharmaceutical excipients. In this work were studied the compatibility and the thermal behavior of isoniazid and pharmaceutical excipients, commonly used for the formulation of solid dosage forms. Colloidal silicon dioxide, corn starch, crospovidone, hypromellose, lactose, magnesium stearate, mannitol, microcrystalline cellulose, povidone, sodium croscarmellose, sodium starch glycolate, stearic acid and talc were the excipients employed in these experiments. The compatibility was analyzed testing binary physical drug/excipient admixtures. The effect of wet granulation and compression was also investigated, in this case especially between isoniazid, fillers and lubricant. For almost all excipients no incompatibilities with isoniazid were observed. Interactions were detected when the drug substance was added to stearic acid, sodium starch glycolate, lactose, mannitol and povidone. Isoniazid formed a euthetic mixture with mannitol, whereas a possible chemical reaction occurred between isoniazid and lactose. Wet granulation and compaction of the tested admixtures did not affect the results observed above. These observations were confirmed by non-thermal techniques, such as X-Ray diffractometry, infrared spectroscopy and nuclear magnetic resonance.
7

XRF för kvalitetskontroll av farmaceutiska råvaror : - metodutveckling och utbildning av användare

Danielsson, Linnea January 2012 (has links)
Detta examensarbete dokumenterar arbetet med utveckling, införande och dokumentation av en nymetod för identitetsbestämning av farmaceutiska råvaror med röntgenfluorescens. Metoden ärutvecklad för att användas på laboratorier för kvalitetskontroll på AstraZeneca i Södertälje. Syftetmed arbetet var att utveckla en robust och effektiv metod samt att utbilda användarna i dethanteringssätt som krävs för att utföra snabba och korrekta analyser. Rapporten presenterarteknologin bakom röntgenfluorescensinstrument och vilka felkällor som kan påverka resultaten samtde pedagogiska teorier som använts för att beskriva det praktiska arbete som äger rum pålaboratoriet. Metoden och de försök som föregick metoden presenteras, och resultat och beslutdiskuteras. Hur utbildningen planerades, genomfördes och utvärderades presenteras också. / This master thesis is the documented work of the development, implementation and documentationof a new method for identification of pharmaceuticals excipients using X-ray fluorescence. Themethod is supposed to be used at the laboratory for quality control at AstraZeneca, Södertälje. Thepurpose of the thesis was to develop a stout and effective method and to educate the users in theskills needed to perform fast and correct analyses. This thesis presents the technology behind XRFinstruments and which sources of errors that could affect the results as well as the pedagogicaltheories used to describe the practical work that takes place at the laboratory. The method and theexperiment that preceded the method are presented, and the results and decisions are discussed.How the education was planned, performed and evaluated is also presented.
8

Estudo retrospectivo sobre o uso de medicamentos em neonatos internados em uma Unidade de Terapia Intensiva Neonatal em BrasÃlia-DF / Retrospective study of drug use in newborns admitted in a Neonatalintensive Care Unit in Brasilia - DF

Alcidesio Sales de Souza Junior 28 August 2014 (has links)
nÃo hà / Neonatos internados em unidade de terapia intensiva neonatal (UTIN) sÃo expostos a uma grande variedade de medicamentos, a maioria sem dados de seguranÃa e eficÃcia. Descrever o perfil de uso de medicamentos em neonatos em UTIN de um hospital pÃblico no Brasil de acordo com dados de registro do medicamento e potencial nocivo destes, foi o objetivo do trabalho. Trata-se de um estudo descritivo retrospectivo sobre uso de medicamentos em UTIN, envolvendo neonatos internados por mais de 24 horas e dados de prescriÃÃo coletados em prontuÃrio eletrÃnico durante o perÃodo de janeiro a junho do ano de 2012. InformaÃÃes sobre os medicamentos, com base nas bulas, foram comparadas com o British National Formulary for Children 2012-2013 e a base de dados Thomson Micromedex. O potencial nocivo de medicamentos e excipientes foi avaliado conforme a literatura. Neonatos foram categorizados em grupos de idade gestacional (IG). Os dados foram submetidos à anÃlise descritiva e testes de distribuiÃÃo (ANOVA, Teste U de Mann-Whitney, Kruskal-Wallis, qui-quadrado de Pearson) por IG com o nÃvel de significÃncia de p < 0,05. IncluÃram-se 192 neonatos, a maioria prÃ-termo, com mediana de 33 semanas de IG, totalizando 3.617 neonatos-dia. Registraram-se 3.290 prescriÃÃes, mÃdia 17,1 prescriÃÃes/neonato (DP  17,9) e 8,8 medicamentos/neonato (DP  5,9), maiores em neonatos mais imaturos (p < 0,05). Anti-infecciosos de uso sistÃmico, medicamentos para o sangue e ÃrgÃos formadores do sangue, trato alimentar e metabolismo apresentaram maior utilizaÃÃo, variando conforme a IG. Neonatos apresentaram maior exposiÃÃo a gentamicina seguido por ampicilina, heparina e fitomenadiona. A maioria dos neonatos (99,5%) foi exposta a medicamentos nÃo licenciados (NL) e de uso nÃo padronizado (NP), mais frequentes em neonatos com IG < 28 semanas (p < 0,05). Mais de 70% dos RN estiveram expostos a algum medicamento potencialmente perigoso (MPP), com maior frequÃncia em neonatos com IG < 31 semanas (p < 0,05). Praticamente todos os neonatos estiveram expostos a excipientes nocivos (EN) e potencialmente nocivos, sendo maior o nÃmero de formulaÃÃes prescritas a neonatos mais imaturos. Metilparabeno, propilparabeno e polissorbato 80 foram os EN aos quais os neonatos estiveram mais expostos, principalmente nas formulaÃÃes de domperidona soluÃÃo oral, polivitamÃnicos soluÃÃo oral e fentanila soluÃÃo injetÃvel. Neonatos em UTIN no Brasil, tal como em outras realidades, estÃo expostos a uma variedade de medicamentos NL, NP e com potencial nocivo, uma situaÃÃo preocupante. Alternativas seguras e estudos sÃo necessÃrios sobre esse tema. / Neonates admitted to neonatal intensive care unit (NICU) are exposed to a wide variety of drugs most without data on safety and efficacy. To describe the drug use profile of neonates in NICU of a public hospital in Brazil according to the drugs records and harmful potential of drugs and pharmaceutical excipients. Descriptive and retrospective study of drug use in NICU, with neonate inpatients for over 24 hours and prescription data from electronic medical records over the period from January to June, 2012. Drug information found in the package leaflets were compared with information in the British National Formulary for Children 2012-2013 and in the Thomson Micromedex database. The drug and excipients harmful potential was evaluated according to the literature. Neonates were categorized into groups of gestational age (GA). The data were analyzed using descriptive analysis and Distribution tests tests (ANOVA Mann-Whitney U, Kruskal-Wallis and Pearson's chi-squared) by GA, with a significance level of p <0.05. Were included 192 neonates, most preterm with median 33 weeks of GA and a total of 3.617 neonates-day. Were registered 3,290 prescriptions, average 17.1 prescriptions/neonate (SD  17.9) and 8.8 drugs/neonate (SD  5.9), higher in most immature neonates (p < 0.05). The anti-infectives for systemic use, blood and blood forming organs, alimentary tract and metabolism drugs groups showed increased use among the neonates, varying according to the GA. Neonates had higher exposure to gentamicin followed by ampicillin, heparin and phytomenadione. Most neonates (99.5%) were exposed to unlicensed drugs (UL) and off label use (OL), more frequently those with GA < 28 weeks (p < 0.05). More than 70% of the neonates were exposed to any high-alert medications, with higher frequency among neonates with GA < 31 weeks (p < 0.05). Almost all neonates were exposed to harmful and potentially harmful excipients, being greater the number of formulations prescribed to more immature neonates. Gentamicin (sulfate) injectable Solution 10 mg/mL (1 mL), fentanyl solution injectable 0.05 mg/mL (10 mL) and sodium heparin injectable solution were the containing harmful excipients formulations to which neonates were most exposed. Neonates in Brazilian NICU, as in other settings, are exposed to a variety of OL, UL and potentially harmful drugs and harmful excipients, an alarming situation. Safety alternatives and more studies are needed on this topic.

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