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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.
11

Dry Powders Inhalers (DPI) obtidos a partir de nanocápsulas de núcleo lipídico contendo budesonida : caracterização, avaliação in vivo em modelo animal de asma e da toxicidade in vitro em cultura celular

Ortiz, Manoel January 2016 (has links)
A asma é definida como uma doença inflamatória crônica de caráter multifatorial, caracterizada pela obstrução reversível das vias aéreas, denso infiltrado inflamatório e hiper-reatividade brônquica a estímulos externos. Clinicamente, a doença é marcada por sintomas episódicos de dispneia, sibilo, tosse seca e sensação de aperto no peito. A terapia convencional da asma compreende o uso de anti-inflamatórios e broncodilatadores. A budesonida é um glicocorticoide esteroide e é dos fármacos mais utilizados na terapêutica da asma. No entanto, a budesonida apresenta baixa biodisponibilidade oral e o uso prolongado pode levar a efeitos adversos graves como afinamento da pele e supressão adrenocortical. No desenvolvimento de novas formulações, a avaliação da toxicidade é de extrema importância. Por conseguinte, o uso de cultura celular é de grande valia no desenvolvimento de protocolos para avaliação da toxicidade de novas formulações. Adicionalmente, a nanotecnologia é uma ferramenta importante para resolver problemas de biodisponibilidade e para contornar efeitos adversos da terapêutica convencional. Desta forma, o objetivo desta tese foi desenvolver um novo sistema nanoestruturado na forma de pó seco para inalação (Dry powders inhalers – DPI), obtido por aspersão contendo budesonida encapsulada, visando o tratamento da asma aguda e crônica. Essa proposta foi baseada na obtenção de um sistema pulverulento nanoestruturado com tamanho reduzido e controlado, visando a entrega pulmonar da budesonida. Na etapa de pré-formulação foi realizado um estudo fatorial avaliando diferentes métodos de preparação das nanocápsulas e os adjuvantes de secagem utilizados. As análises de tamanho de partícula, da formulação selecionada (nanocápsulas contendo budesonida e secas por aspersão com leucina) mostraram um tamanho reduzido e adequado para a administração pulmonar (2,7 μm). A morfologia demonstrou que estas partículas possuem um tamanho reduzido, forma esférica e superfície irregular, características importantes para a administração pulmonar. Quando analisada a distribuição pulmonar in vitro, em Impactador de Andersen, a formulação apresentou uma fração de partículas finas (Fine Particle Fraction – FPF) de 28%. Analisando os resultados dos experimentos em modelos de asma aguda e crônica induzidos por ovalbumina, os resultados da mecânica respiratória e função pulmonar mostraram uma diminuição na resistência e na elastância pulmonar, quando a budesonida nanoencapsulada foi utilizada, quando comparada com uma formulação comercial de budesonida, nas duas doses utilizadas (0,5 e 1,0 mg/Kg). Esse tratamento com nanocápsulas também mostrou eficiência na redução da inflamação, pela redução do número de leucócitos totais no fluido de lavagem bronco alveolar (Broncho Alveolar Lavage Fluid – BALF) e, principalmente, redução significativa no número dos eosinófilos no infiltrado pulmonar. Corroborando esses resultados, a quantificação da eotaxina – 1 e das citocinas pró-inflamatórias foram reduzidas, quando comparadas ao tratamento comercial. A análise histopatológica mostrou que quando o tratamento com as nanocápsulas foi utilizado, a produção de muco foi reduzida, bem como a produção de fibrose sub-epitelial, sugerindo um possível efeito sobre o remodelamento tecidual. Os resultados de toxicidade utilizando linhagem celular epitelial pulmonar (H441) mostrou uma redução na toxicidade da budesonida, quando encapsulada nas nanopartículas, tanto na forma de suspensão como na forma pulverulenta. Essa redução da toxicidade foi de 75% e de 50%, na dose de 100 μg/mL, para a suspensão e para o DPI, respectivamente. O conjunto dos resultados obtidos mostrou a potencial aplicabilidade da budesonida nanoencapsulada para o tratamento da asma, utilizando esse novo sistema DPI. / Asthma is characterized as a chronic inflammatory disease developed by multifactorial aspects such as genetic predisposition and exposure to environmental factors such as pollution, smoke and microorganisms. The conventional asthma therapy comprises the use of bronchodilators and anti-inflammatory. Budesonide is a glucocorticoid and is the most frequently used therapy in the treatment of asthma. However, this drug has low oral bioavailability and long term use may lead to adverse effects such as skin thinning and adrenal suppression. The evaluation of the toxicity of new formulation has critical role in the pharmaceutical development. The use of cell culture experiments can help this aspect. Additionally, nanotechnology is an important tool to solve problems regarding bioavailability and to circumvent adverse effects of conventional therapy. The aim of this work was to develop a nanostructured system as dry powder inhaler (DPI) containing budesonide loaded, obtained by spray-drying, targeting the treatment of acute and chronic asthma. This proposal was based on obtaining a nanostructured powder system with reduced and controlled size, aiming an alternative to treatment of asthma. A factorial study comparing different methods to produce the nanocapsules as well as the type of drying adjuvants was performed. The particle size of the selected formulation was 2.7 μm, an adequate reduced size suitable for pulmonary administration. The morphology of these particles showed a small size, spherical shape and irregular surface. All these characteristics are important for pulmonary administration. When analyzed the in vitro pulmonary distribution of the DPI, using an Andersen Cascade Impactor, showed a fine particle fraction (FPF) of 28%. Analyzing the results of the biological experiments, the mechanical respiratory and pulmonary function showed a decrease in lung elastance and resistance when budesonide was used nanoencapsulated compared with a commercial formulation of budesonide in two doses (0.5 and 1.0 mg / kg). Both treatments also showed nanocapsules efficiency in reduction of inflammation by reducing the total of leukocytes in the bronchial alveolar lavage fluid (BALF) and especially significant reduction in eosinophil infiltration in the lung tissue. Corroborating with these results, the quantification of eotaxin - 1 and proinflammatory cytokines was reduced when compared to commercial budesonide treatment. Histopathological analysis showed that when treatment with the nanocapsules was used, mucus production was reduced and reversed the phenomena of airway remodeling. The cytotoxicity assay by Alamar blue using the bronchial epithelium cell line (H441) showed a reduction on the toxicity of budesonide when the nanocapsules were used even in suspension or in the DPI. The cytotoxicity reduction were 75 and 50%, at 100 μg/mL, for the suspension and the DPI, respectively. All these results show that budesonide-loaded nanocapsules in dry powder inhaler is a promising approach for the treatment of asthma.
12

Sistemas híbridos nanoestruturados contendo Budesonida para o tratamento de colite ulcerativa

Akkari, Alessandra Cristina Santos January 2015 (has links)
Orientadora: Profa. Dra. Daniele Ribeiro de Araujo / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biossistemas, 2015. / It is expected the improvement of BUD physicochemical properties through complexation with CD and the incorporation of BUD:HP-â-CD inclusion complex into PL-based hydrogels, contributing to a longer duration of anti-inflammatory effect associated with high bioadhesion in the treatment of ulcerative colitis. In this work, we propose the study of the system BUD:HP-â-CD inclusion complex incorporated into PL407 and PL407-PL403, since the micelles assembling to the thermoreversible hydrogels considering structural and thermodynamics parameters related to inclusion complex formation, micellization and sol-gel transition phase, as well as the interaction between BUD:HP-â-CD complex and PL. Complexation between BUD and HP-â-CD was confirmed by phase solubility studies (1:1 stoichiometry, Kc = 8662.8 M-1), DSC and microscopy analyzes. BUD solubility on upper and lower simulated colon fluids was improved in a dependence of both carriers association (HP-â-CD and PL407 or PL407-PL403). Micellar hydrodynamic diameter determination showed the interaction between HP-â-CD and PL blocks, as well as the reorganization of the micellar system in the presence of BUD. Micellization temperature (Tm) was not shifted, but in the presence of BUD or HP-â-CD, an increase on ÄH° values was observed for all formulations. Sol-gel phase transition studies showed that in the presence of BUD, HP-â-CD or BUD:HP-â-CD complex, the association PL407-PL403 favored the gel formation close to the physiological temperature. 1H-NMR studies revealed the interaction between PL407 and HP-â-CD and FTIR confirmed the effective incorporation of the drug and the inclusion complex in PL system. The in vitro drug release was sustained and the release rate was slowed by the addition of inclusion complex (under 38% of the BUD released after 2 days), suggesting a prolonged anti-inflammatory effect. Drug release of PL407 was best explained by Higuchi and Korsmeyer-Peppas (n < 0.5), indicating the Fickian diffusion mechanism. In the binary system with inclusion complex, drug release follows Hixson-Crowell cube root law, specially in lower colon fluid, indicating the erosion of polymer matrix as a mechanism that influences the BUD release profile. Sol/gel phase transition, solubility, turbidity, FTIR and in vitro release tests revealed no competitive displacement of BUD from the hydrophobic HP-â-CD cavity evoked by PL407 or PL407-PL403 addition. These promising findings point out the BUD-HP-â-CD in 20 % or 18/2 PL-based hydrogels as strategies for future in vivo investigations and also the development of new pharmaceutical formulations looking forward the treatment of ulcerative colitis. / O presente trabalho propoe a otimizacao das propriedades fisico-quimicas do glicocorticosteroide budesonida (BUD) para o tratamento da colite ulcerativa (COL), por meio da complexacao com ciclodextrinas (CD), bem como a incorporacao do complexo de inclusao farmaco:CD em hidrogeis a base de Poloxamer (PL), contribuindo para uma maior duracao do efeito antiinflamatorio associado a permanencia no local de aplicacao. Desta forma, para o complexo de inclusao BUD:HP-¿À-CD, como tambem para os hidrogeis termorreversiveis de PL407 e de PL407/PL403, foram realizados diferentes ensaios de caracterizacao fisico-quimica, abrangendo desde uma analise estrutural e morfologica ate ensaios de liberacao in vitro. A complexacao entre BUD e HP-¿À-CD foi confirmada por meio dos ensaios de solubilidade de fase (estequiometria 1:1), Calorimetria Diferencial Exploratoria (DSC), Microscopia Eleronica de Varredura (MEV), Ressonancia Magnetica Nuclear (RMN) e Espectroscopia no Infravermelho por Transformada de Fourier (FTIR), destacando a elevada afinidades entre a molecula do farmaco e a cavidade hidrofobica da HP- ¿À-CD (Kc = 8.662,8 M-1). A solubilidade da BUD em fluidos simulados do colon superior (FSCS) e inferior (FSCI) foi melhorada de forma dependente a ambos os carreadores (HP-¿À- CD e PL), sugerindo o efeito aditivo dos sistemas polimericos na solubilizacao do farmaco. Na presenca de BUD ou de BUD:HP-¿À-CD, a associacao PL407/PL403 favoreceu a formacao da estrutura gel proximo a temperatura fisiologica, otimizando a viscosidade da formulacao em relacao a forma comercial (enema). A analise termodinamica mostrou ocorrencia de um processo endotermico espontaneo, embora tenha sido observado um aumento nos valores de AH¿ para todas as formulacoes. Estudos de RMN-H1 revelaram a interacao entre PL407 e HP-¿À-CD, nao sendo o mesmo identificado para o PL403. Os resultados de FTIR comprovaram a efetiva incorporacao do farmaco e do complexo de inclusao nos sistemas PL, que sofreram uma desorganizacao na cadeia polimerica e a formacao de um novo arranjo como consequencia da interacao entre os aditivos e o PL. Ensaios de liberacao in vitro atestaram a efetividade dos sistemas polimericos associados ao complexo de inclusao BUD:HP-¿À-CD, diminuindo significativamente o fluxo e prolongando a liberacao, que alcancou menos de 38% de farmaco liberado apos 2 dias de experimentacao, nas formulacoes 18/2% PL407/PL403 e 20% PL407. O perfil cinetico dos sistemas isolados de PL407 foi melhor descrito por Higuchi e Korsmeyer-Peppas, com expoente de liberacao inferior a 0,5, indicando a difusao Fickiana como mecanismo predominante. A incorporacao do complexo de inclusao no sistema binario conferiu ao perfil de liberacao uma aderencia ao modelo de Hixson-Crowell, indicando a erosao da matriz polimerica como mecanismo que influencia a liberacao do farmaco. Esses resultados promissores atestam a efetividade dos sistemas hibridos propostos no presente trabalho, apontando o complexo de inclusao BUD:HP-¿À-CD em hidrogeis de 20% PL e 18/2% PL407/PL403 como estrategia para investigacoes futuras in vivo, visando otimizar o tratamento da COL.
13

Efetividade e segurança da budesonida nebulizada no controle da crise aguda de sibilância em crianças menores de três anos não responsivas ao fenoterol /

Silva, Margarete Lopes da. January 2007 (has links)
Resumo: Objetivos: Investigar a eficácia e segurança da budesonida comparada à prednisona na crise aguda de sibilância. Métodos: Estudo prospectivo, duplo-cego, randomizado comparou a budesonida nebulizada (2mg diários com redução gradual para 0,5mg, n=30, grupo A) com a prednisona (n= 30, grupo B) e placebo (n=15, grupo C) durante sete dias, envolvendo crianças de 40 dias a 36 meses em Santo André, SP, Brasil. Os critérios de inclusão foram: crianças nutridas, sem uso de corticosteróide, hospitalizadas por crise aguda grave de sibilância. Escore clínico foi mensurado nos períodos: 20, 40, 60 e 90 minutos, 2,4,6,12,24 horas e, após diariamente por uma semana. A função adrenal foi avaliada por dosagem de cortisol salivar nos dias de acompanhamento 3,5,7,10 e 15. Saliva foi coletada pela manhã e tarde. Cortisol foi dosado por radioimunoensaio com anticorpo anticortisol- 3-oxima albumina bovina. Resultados: Budesonida proporcionou melhora clínica mais rápida do que prednisona ou placebo nas primeiras 24h do tratamento (A 56 e B 282, p= 0,0000, Mann Whitney) (C 434 minutos). O percentil de interrupção por piora clínica foi: A: 3,3, B: 43, C: 40. Todos os grupos exibiram concentração de cortisol salivar mais alta de manhã do que tarde. Grupo A mostrou diminuição da dosagem vespertina no 10º dia de acompanhamento (p< 0,0001). Conclusão: Budesonida nebulizada proporcionou efeitos benéficos mais precocemente (1h) em exacerbações graves de broncoespasmo, sem alterar o ritmo circadaino. / Abstract: Background: Inhaled steroids are an effective and recommended prophylactic treatment for moderate to severe asthma, but in acute exacerbations are not advocated as conventional therapy. Objectives: To investigate the efficacy of budesonide as compared to prednisone in severe acute wheezing.Methods: In prospective, double-blind, randomized study nebulized budesonide (2mg with gradual reduce to 0,5mg, n= 30, group A) was compared with oral prednisone (n= 30, group B) and placebo (n= 15, group C) during seven days, enrolling children aged 40 days to 36 months in Santo André, SP, Brazil. Inclusion criteria were: well-nourished, free from corticosteroid use and hospitalized for severe acute wheezing. Index score clinical was measured in the periods: 20, 40, 60 and 90 minutes; 2,4,6,12,24 h and then daily for a week. The adrenal function was availably for cortisol salivary dosage in the 3,5,7,10 and 15 days of treatment. Saliva was collected in the morning and afternoon. Cortisol was radioimmunoassayed with cortisol 3- oxime-bovine albumin antiserum. Results: Budesonide displayed a faster clinical improvement compared with prednisone or placebo into 24h of treatment (A 56 and B 282 minutes, p < 0,0000). The percentile of interruption by worse clinical was: A 3.3; B 43; C 40. All groups exhibited higher cortisol concentration during the morning than afternoon (p < 0.0001). Group A showed lower afternoon value in the 10th day (p < 0,001). Conclusion: nebulized budesonide brings early beneficial effects (1h) in severe acute exacerbations of wheezing without adrenal suppression, without changing the circadian rhythm. / Orientador: Giesela Fleischer Ferrari / Coorientador: Márcia Carvalho Mallozi / Banca: José Roberto Fioretto / Banca: Jaime Olbrich Neto / Banca: Tatiana Rozov / Banca: Neusa Falbo Wandolsen / Possue ERRATA encadernada separadamente / Doutor
14

Dry Powders Inhalers (DPI) obtidos a partir de nanocápsulas de núcleo lipídico contendo budesonida : caracterização, avaliação in vivo em modelo animal de asma e da toxicidade in vitro em cultura celular

Ortiz, Manoel January 2016 (has links)
A asma é definida como uma doença inflamatória crônica de caráter multifatorial, caracterizada pela obstrução reversível das vias aéreas, denso infiltrado inflamatório e hiper-reatividade brônquica a estímulos externos. Clinicamente, a doença é marcada por sintomas episódicos de dispneia, sibilo, tosse seca e sensação de aperto no peito. A terapia convencional da asma compreende o uso de anti-inflamatórios e broncodilatadores. A budesonida é um glicocorticoide esteroide e é dos fármacos mais utilizados na terapêutica da asma. No entanto, a budesonida apresenta baixa biodisponibilidade oral e o uso prolongado pode levar a efeitos adversos graves como afinamento da pele e supressão adrenocortical. No desenvolvimento de novas formulações, a avaliação da toxicidade é de extrema importância. Por conseguinte, o uso de cultura celular é de grande valia no desenvolvimento de protocolos para avaliação da toxicidade de novas formulações. Adicionalmente, a nanotecnologia é uma ferramenta importante para resolver problemas de biodisponibilidade e para contornar efeitos adversos da terapêutica convencional. Desta forma, o objetivo desta tese foi desenvolver um novo sistema nanoestruturado na forma de pó seco para inalação (Dry powders inhalers – DPI), obtido por aspersão contendo budesonida encapsulada, visando o tratamento da asma aguda e crônica. Essa proposta foi baseada na obtenção de um sistema pulverulento nanoestruturado com tamanho reduzido e controlado, visando a entrega pulmonar da budesonida. Na etapa de pré-formulação foi realizado um estudo fatorial avaliando diferentes métodos de preparação das nanocápsulas e os adjuvantes de secagem utilizados. As análises de tamanho de partícula, da formulação selecionada (nanocápsulas contendo budesonida e secas por aspersão com leucina) mostraram um tamanho reduzido e adequado para a administração pulmonar (2,7 μm). A morfologia demonstrou que estas partículas possuem um tamanho reduzido, forma esférica e superfície irregular, características importantes para a administração pulmonar. Quando analisada a distribuição pulmonar in vitro, em Impactador de Andersen, a formulação apresentou uma fração de partículas finas (Fine Particle Fraction – FPF) de 28%. Analisando os resultados dos experimentos em modelos de asma aguda e crônica induzidos por ovalbumina, os resultados da mecânica respiratória e função pulmonar mostraram uma diminuição na resistência e na elastância pulmonar, quando a budesonida nanoencapsulada foi utilizada, quando comparada com uma formulação comercial de budesonida, nas duas doses utilizadas (0,5 e 1,0 mg/Kg). Esse tratamento com nanocápsulas também mostrou eficiência na redução da inflamação, pela redução do número de leucócitos totais no fluido de lavagem bronco alveolar (Broncho Alveolar Lavage Fluid – BALF) e, principalmente, redução significativa no número dos eosinófilos no infiltrado pulmonar. Corroborando esses resultados, a quantificação da eotaxina – 1 e das citocinas pró-inflamatórias foram reduzidas, quando comparadas ao tratamento comercial. A análise histopatológica mostrou que quando o tratamento com as nanocápsulas foi utilizado, a produção de muco foi reduzida, bem como a produção de fibrose sub-epitelial, sugerindo um possível efeito sobre o remodelamento tecidual. Os resultados de toxicidade utilizando linhagem celular epitelial pulmonar (H441) mostrou uma redução na toxicidade da budesonida, quando encapsulada nas nanopartículas, tanto na forma de suspensão como na forma pulverulenta. Essa redução da toxicidade foi de 75% e de 50%, na dose de 100 μg/mL, para a suspensão e para o DPI, respectivamente. O conjunto dos resultados obtidos mostrou a potencial aplicabilidade da budesonida nanoencapsulada para o tratamento da asma, utilizando esse novo sistema DPI. / Asthma is characterized as a chronic inflammatory disease developed by multifactorial aspects such as genetic predisposition and exposure to environmental factors such as pollution, smoke and microorganisms. The conventional asthma therapy comprises the use of bronchodilators and anti-inflammatory. Budesonide is a glucocorticoid and is the most frequently used therapy in the treatment of asthma. However, this drug has low oral bioavailability and long term use may lead to adverse effects such as skin thinning and adrenal suppression. The evaluation of the toxicity of new formulation has critical role in the pharmaceutical development. The use of cell culture experiments can help this aspect. Additionally, nanotechnology is an important tool to solve problems regarding bioavailability and to circumvent adverse effects of conventional therapy. The aim of this work was to develop a nanostructured system as dry powder inhaler (DPI) containing budesonide loaded, obtained by spray-drying, targeting the treatment of acute and chronic asthma. This proposal was based on obtaining a nanostructured powder system with reduced and controlled size, aiming an alternative to treatment of asthma. A factorial study comparing different methods to produce the nanocapsules as well as the type of drying adjuvants was performed. The particle size of the selected formulation was 2.7 μm, an adequate reduced size suitable for pulmonary administration. The morphology of these particles showed a small size, spherical shape and irregular surface. All these characteristics are important for pulmonary administration. When analyzed the in vitro pulmonary distribution of the DPI, using an Andersen Cascade Impactor, showed a fine particle fraction (FPF) of 28%. Analyzing the results of the biological experiments, the mechanical respiratory and pulmonary function showed a decrease in lung elastance and resistance when budesonide was used nanoencapsulated compared with a commercial formulation of budesonide in two doses (0.5 and 1.0 mg / kg). Both treatments also showed nanocapsules efficiency in reduction of inflammation by reducing the total of leukocytes in the bronchial alveolar lavage fluid (BALF) and especially significant reduction in eosinophil infiltration in the lung tissue. Corroborating with these results, the quantification of eotaxin - 1 and proinflammatory cytokines was reduced when compared to commercial budesonide treatment. Histopathological analysis showed that when treatment with the nanocapsules was used, mucus production was reduced and reversed the phenomena of airway remodeling. The cytotoxicity assay by Alamar blue using the bronchial epithelium cell line (H441) showed a reduction on the toxicity of budesonide when the nanocapsules were used even in suspension or in the DPI. The cytotoxicity reduction were 75 and 50%, at 100 μg/mL, for the suspension and the DPI, respectively. All these results show that budesonide-loaded nanocapsules in dry powder inhaler is a promising approach for the treatment of asthma.
15

Safety and Efficacy of Budesonide as an alternative to Prednisone for Liver Transplant Immune Suppression: Results of a pilot phase 2a trial

Bari, Khurram January 2019 (has links)
No description available.
16

Investigation to Identify the Influence of Mannitol as a Carrier on the Ex-Vivo Dose Emission and the In-Vitro Aerodynamic Dose Emission Characteristics of Dry Powder Inhalers of Budesonide

Aloum, Fatima January 2020 (has links)
This study provides, for the first time, an ex vivo comparative evaluation of formulations of budesonide with crystallised β-form mannitol, commercial DPI grade mannitol and lactose. The lactose-budesonide was the marketed Easyhaler® 200 g formulation. Ex vivo assessment of deposition using the Easyhaler® multi-dose high resistance inhaler with reservoir was compared with the RS01® single dose capsule low resistance inhaler at two different inhalation rates. Aerodynamic characteristics, flow and surface energies were investigated together with in vitro and ex vivo assessment of drug deposition. Dose emission was greater for all formulations with higher inhalation flow, indicating greater detachment of drug from carrier, and greater with the Easyhaler®, highlighting the importance of correct device for formulation. Emission was lowest at both inhalation rates for crystallised mannitol due to poor flowability associated with elongated particle shape which resulted in interception deposition. Surface energies were also implicated; closely matched polar surface energy of carrier and drug may be an important inhibiting factor. The promising aerodynamic characteristics of crystallised mannitol with the RS01® inhaler and lactose-budesonide from in vitro assessment were not supported by ex vivo results, highlighting the need for careful selection of device.
17

Drug nanosizing using microfluidic reactors. Development, characterisation and evaluation of corticosteroids nano-sized particles for optimised drug delivery.

Ali, Hany S.M. January 2010 (has links)
Over recent years the delivery of nanosized drug particles has shown potential in improving bioavailability. Drug nanosizing is achieved by ¿top-down¿ and by ¿bottom-up¿ approaches. Owing to limitations associated with the top-down techniques, such as high energy input, electrostatic effects, broad particle size distributions and contamination issues, great interest has been directed to alternative bottom up technologies. In this study, the hypothesis that microreactors can be used as a simple and cost-effective technique to generate organic nanosized products is tested using three steroids (hydrocortisone, prednisolone and budesonide). Arrested antisolvent nanoprecipitation using ethanol (solvent) and water (antisolvent) was conducted within the microreactors. To enable experimental design for the microreactor studies, solubility profiles in different ethanol-water combinations at 25 °C were explored. All three drugs¿ solubility increased with increasing ethanol concentration showing maxima at 80-90 % v/v ethanol-water mixtures. Because of the complex multivariate microfluidic process, artificial neural network modelling was then employed to identify the dominant relationships between the variables affecting nanoprecipitation (as inputs) and the drug particle size (as output). The antisolvent flow rate was found to have the major role in directing drug particle size. Based on these successful findings, the potential of preparing pharmaceutical nanosuspensions using microfluidic reactors was researched. A hydrocortisone (HC) nanosuspension (NS) was prepared by introducing the generated drug particles into an aqueous solution of stabilizers stirred at high speed with a propeller mixer. A tangential flow filtration system was then used to concentrate the prepared NS. Results showed that a stable narrow sized HC NS of amorphous spherical particles 500 ± 64 nm diameter and zeta potential ¿18 ± 2.84 mV could be produced. The ocular bioavailability of a microfluidic precipitated HC NS (300 nm) was assessed and compared to a similar sized, milled HC NS and HC solution as a control. The precipitated and the milled NS achieved comparable AUC0-9h of 28.06 ± 4.08 and 30.95 ± 2.2, respectively, significantly (P < 0.01) higher than HC solution (15.86 ± 2.7). These results illustrate the opportunity to design sustained release ophthalmic formulations. Going nano via microfluidic precipitation was also exploited to tailor budesonide (BD) NS for pulmonary administration. The in vitro aerosolization by nebulization of a BD NS was studied in comparison with a commercial BD microsuspension. Overall, the fine particle fraction generated from BD NS (56.88 ± 3.37) was significantly (P < 0.05) higher than the marketed BD (38.04 ± 7.81). The mean mass aerodynamic diameter of BD NS aerosol (3.9 ± 0.48 ¿m) was significantly smaller (P < 0.05) than the microsuspension (6.2 ± 1.09 ¿m) indicating improved performance for BD NS. In conclusion, findings of this study support the hypothesis of using microfluidic nanoprecipitation as a promising and economical technique of drug nanosizing. / Egyptian Government (Ministry of High Education)
18

Evaluating the use of cross-linked PVA nanoparticles for gene and drug delivery

Finter, Wayne January 2010 (has links)
Due to the safety concerns surrounding viral vectors, non-viral alternatives are desirable for fulfilling the aim of gene therapy. In this project gel mobility shift assays demonstrated how cross-linked PVA nanoparticles successfully form complexes with plasmid DNA and are of a size and charge that should, theoretically, permit endocytosis by eukaryotic cells. However, during in vitro transfection studies no reporter (GFP) gene expression was noted. The collective evidence from electroporation, fluorescent-DNA-tagging, Lipofectin® or calcium phosphate chimeric and chloroquine experiments suggest that a lack of cell uptake is responsible. Nevertheless, the same cross-linked PVA nanoparticles have been shown to exhibit much promise in the field of drug delivery during in vitro experiments, even when used to target the same cell types as those used during transfection studies. Nanagel®, a cross-linked PVA nanoparticle containing budesonide, achieved higher levels of drug delivery than a commercially available form of the same drug (Pulmicort®) after 1 or 24 hours drug exposure. Furthermore, by measuring superoxide production during a stimulated respiratory burst, the budesonide delivered to cells appears fully functional and significantly more effective than Pulmicort® in preventing the formation of reactive oxygen species, following a 24-hour pre-treatment period with the formulation. These findings have exciting possibilities for the use of hard-to-dissolve corticosteroids in the treatment of respiratory disease. / AGT Sciences Ltd
19

Vibrational spectroscopic study of budesonide

Edwards, Howell G.M., Ali, H.R.H., Kendrick, John, Munshi, Tasnim, Scowen, Ian J. January 2007 (has links)
No / The Raman spectrum of budesonide is reported for the first time, and molecular assignments are proposed on the basis of ab initio BLYP DFT calculations with a 6-31 G* basis set and vibrational wavenumbers predicted on a quasi-harmonic approximation. Comparison with previously published infrared data has explained several spectral features, and the relative band intensities in the CO and CC stretching regions are interpreted. The results from this study provide data that can be used for the preparative process monitoring of budesonide, an important steroidal pharmaceutical in various dosage forms, and its interaction with excipients and other components.
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In-Vitro In-Vivo Correlation (IVIVC) of Inhaled Products Using Twin Stage Impinger

Al Ayoub, Y., Buzgeia, Asma, Almousawi, Ghadeer, Mazhar, H.R.A., Alzouebi, B., Gopalan, Rajendran C., Assi, Khaled H. 08 December 2021 (has links)
No / In vitro dissolution testing as a form of quality control has become a necessity in the pharmaceutical industry. As such, the need to establish a method that investigates the in vitro dissolution profile of inhaled products should be taken into account. The prime focus in this study was to examine the in-vitro in-vivo correlation utilising a modified version of the Twin Stage Impinger and to promote an in vitro dissolution model by enhancing the Fine Particle Dose (FPD) collection method for dry powder inhalers. The Twin Impinger was modified by inserting a stainless steel membrane holder disk in the base of the lower chamber. The design, with optimum drug deposition, was adopted for the dissolution study of budesonide and salbutamol. Afterwards, the membrane holder system was placed in the bottom of the dissolution vessel. Phosphate buffer saline (PBS), simulated lung fluid (SLF, Gamble solution) and Phosphate buffer (PB) were used in the study. The paddle dissolution apparatus, containing 300 mL of the medium, was operated at 75 rpm paddle speed. Samples were collected at defined time intervals and analysed using a validated HPLC method. The largest proportion of the budesonide dose was dissolved in PBS compared to PB and SLF. This was due to the presence of surfactant (0.2% w/v polysorbate), which enhances the wettability and the solubility of the poorly soluble drug (budesonide). The similarity factors for PBS and PB were 47.6 and 69.7, respectively, using SLF as a reference, whereas the similarity factor for salbutamol dissolution between PB and SLF was 81.3, suggesting PB is a suitable substitute. Comparison using both the predicted and actual in vivo pharmacokinetics (PK) values of the two drugs, as well as the pattern of their Concentration-Time (c-t) profiles, showed good similarity, which gave an indication of the validity of this in vitro dissolution method.

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