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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.
41

Desenvolvimento de sistemas precursores de fase cristalina para administração intrabolsa periodontal / Development of precursors crystalline phase for intra pocket periodontal administration.

Nunes, Kariane Mendes 21 December 2012 (has links)
A doença periodontal é uma patogenia que afeta as estruturas de suporte dos dentes com formação da bolsa periodontal, e caso não tratada, em estágios mais avançados o periodonto é destruído, ocasionando perda do dente. O tratamento concerne em duas etapas, à remoção mecânica do biofilme e cálculo dentário por raspagem e alisamento radicular e utilização de antimicrobianos. Ainda é comum a utilização de antimicrobiano de ação sistêmica, embora, tenha eficácia reduzida e frequentes efeitos adversos. Em face disto, justifica-se o desenvolvimento de sistemas de liberação sustentada de fármaco intrabolsa periodontal a fim de sanar os inconvenientes da terapia sistêmica. Contudo, aspectos como espaço anatomofisiológico e fluído gengival crevicular intrínsecos à bolsa, são limitações pertinentes durante o desenvolvimento. Portanto, este trabalho teve como objetivo desenvolver sistemas e formulações precursoras de fase líquido cristalina baseados em monolinoleato de glicerila (MLG) e cremophor (CREM) com gelificação in situ em fase líquido cristalina. Por meio de planejamento fatorial 32 foram obtidos 9 sistemas sem adição de fármaco e 9 formulações contendo metronidazol com diferentes razões de MLG/CREM e %H2O. Quando caracterizados por microscopia de luz polarizada e espalhamento de raios-X a baixo ângulo, os sistemas e formulações com menor razão MLG/CREM e conteúdos de água de 5, 10 e 15% apresentaram organização micelar isotrópica. Eles também apresentaram rápida erosão no ensaio de captação de água, inviabilizando sua transição para mesofase. Os sistemas e formulações com média e alta razão MLG/CREM e conteúdos de água de 5, 10 e 15% apresentaram coexistência de fases em transição líquido cristalina. Apresentaram rápida captação de água com transição para fase cúbica. Contudo, com exceção do sistema e formulação com alta razão MGL/CREM e 15% de água, os demais sistemas e formulações, apresentaram propriedades de fluxo ideais para fácil aplicação por seringa acoplada a agulha, e comportamento viscoelástico adequado para promover espalhabilidade e retenção no interior da bolsa. Os sistemas e formulações com média e alta razão de MLG/CREM apresentaram melhor mucoadesão. Dentre as formulações, apenas a com média razão de GML/CREM e 5% de água, apresentou perfil bi-modal de liberação mantendo concentrações de metronidazol acima do MIC por 6 dias, característica desejável para sistemas de liberação intrabolsa periodontal. Portanto, todos os resultados advogam a favor desta formulação como potencial candidata ao emprego clínico como sistema de liberação de fármaco intrabolsa periodontal. / Periodontal disease is a chronic infection that affects the structural supports of the tooth with periodontal pocket formation. If untreated, the periodontium may be destroyed, which can cause the tooth loss in the latest stages of the disease. The treatment for this infection comprises two stages, the mechanical removal of plaque and calculus by scaling and root planing and the use of antimicrobials. It is still common to use systemic antimicrobials, even though it has a reduced efficacy and frequent adverse effects. For the reason, justified the development of systems for sustained release of drug intra-pocket periodontal in order to solve the drawbacks of systemic therapy. The main limitations for the development of these systems are the anatomical and physiological aspects of the periodontal pocket, which includes the limited size and the depth area and the natural irrigate flow of the gingival crevice fluid (GCF). So, this study aimed to develop precursor liquid crystalline systems and formulations based on glyceryl monolinoleate (GML) and cremophor (CREM), with in situ gelation to liquid crystalline phases. Through a 32 factorial design 9 systems without drug and 9 formulations containing metronidazole were obtained. Different ratios of GML / CREM and water percentage were evaluated. When characterized by Small-Angle X-ray Scattering and Polarized Light Microscopy, lower ratio GML / CREM with 5, 10 and 15% H2O produce isotropic micellar organization. They also showed high erosion during water uptake, thus, precluding in situ crystalline transition. Medium and high ratio GML / CREM with 5, 10 and 15% H2O indicated the coexistence of regions in transition to the crystalline phase. They showed characteristic peaks of cubic phases, rapid water uptake, higher viscosity and increased mucoadhesion. Moreover, with the exception of the formulation containing high ratio and high water content, other systems and formulations with medium ratio GML / CREM and 5, 10, 15% of water and high ratio and 5 and 10% of water had flow properties ideal for easy application through needle fitted syringes, viscoelastic behavior appropriate to promote spreadability and might favor retention within the periodontal pocket. However, only the formulation with higher ratio and the lowest water content presented a bimodal release profile of metronidazole, maintaining concentrations above the MIC for 5 days, with the release of 100% of the drug added to the formulation. These are desirable features for delivery systems designed for periodontal pockets. Therefore, all results advocate in favor of the formulation with high ratio of GML / CREM and 5% of water as a potential candidate for clinical use as drug delivery system for the periodontal pocket.
42

Desenvolvimento de filmes mucoadesivos para liberação de fármacos anestésicos na cavidade bucal / Development of mucoadhesive films for anesthetic release in the buccal cavity

Renê Oliveira do Couto 30 March 2015 (has links)
A anestesia local normalmente precede a maioria dos procedimentos odontológicos. Porém, por ser realizada por processo invasivo (injetável), muitas vezes afugentam o paciente do consultório. Portanto, a substituição do processo invasivo por não invasivo, além de inovador traria diversas vantagens a odontologia i.e., possibilitaria o aprimoramento de procedimentos rotineiros e cirúrgicos devido à provável redução de custos, submissão do paciente, facilidade de aplicação e menores riscos de contaminação e intoxicações. Neste intuito, filmes poliméricos hidrofílicos mono ou trilaminados, compostos pelo polímero mucoadesivo HPMC K100 LV, glicerol ou PEG 400 como plastificantes, e contendo os anestésicos locais cloridratos de prilocaína (PCL) e lidocaína (LCL) em diferentes proporções foram desenvolvidos. Os filmes apresentaram flexibilidade e moldabilidade adequadas, além de uniformidade de massa e teor. Tanto a massa total de fármaco nos filmes (11 - 55 mg/0,64cm2), quanto suas contribuições relativas nas misturas (0 - 100% m.m-1) modularam seus perfis e cinéticas de liberação e permeação, além das quantidades retidas no epitélio esofageal suíno. Quantidades menores dos fármacos conduziram aos maiores coeficientes de permeabilidade do LCL. O filme contendo mistura dos fármacos na proporção 1:1 (PCL:LCL) apresentou a melhor relação custo/benefício e foi escolhida para a continuidade dos estudos. O aumento na massa total de fármaco nos filmes de 12,5 para 25 mg aumentou significativamente sua força e trabalho de mucoadesão, mas reduziu sua resistência à tração e módulo de elasticidade. Os filmes apresentaram propriedades mecânicas e de mucoadesão adequadas para a finalidade proposta. A adição de camadas oclusiva (composta por Eudragit® S100 e trietil citrato como plastificante) e mucoadesiva (composta por HPMC K100 LV e policarbofil na proporção 3:1 m.m-1 e PEG 400 como plastificante) aos filmes reduziu significativamente as quantidades dos fármacos liberadas, permeadas e retidas no epitélio e, portanto, a composição e arquitetura dos patches trilaminados deve ser aprimorada de modo a favorecer a hidratação da camada de liberação. Pela primeira vez foi demonstrada a eficiência da técnica de iontoforese (1 mA.cm-2) na promoção da permeação destes fármacos em associação a partir de filmes poliméricos. Para que possa substituir a anestesia injetável (solução a 2%, equivalente a 36 mg de fármaco), a permeação dos fármacos a partir do filme mais promissor (12,5 mg de PCL:LCL 1:1, 3% m.m-1 HPMC K100LV e 30% PEG400 em função da massa de polímero mucoadesivo) deve ser aumentada em pelo menos 30 vezes. / Local anesthesia typically precedes the majority of dental procedures. However, due to be performed using an invasive process (injection), often it scares the patient out from the dentist office. Accordingly, besides its innovative character, the replacement of the painful injection by a noninvasive process might bring several advantages to the dentistry field. It might enable the improvement of routinely and surgical procedures as a function of cost saving, patient compliance, ease of application and lowering the risk of contamination and intoxication. In this pursuit, we developed hydrophilic polymeric films comprised by one or three layers, comprised by the mucoadhesive polymer HPMC K100 LV, glycerol or PEG 400 as plasticizers, and containing the local anesthetic drugs prilocaine (PCL) and lidocaine (LCL) hydrochloride in different proportions. The films showed suitable flexibility and plasticity, besides uniformities of mass and content. Both the total mass of drugs in the films (11 - 55 mg/0.64 cm2), and their relative contribution in the mixtures (0 - 100% w.w-1) have modulated their profiles and kinetics of both delivery and permeation, as well as their amount retained in the porcine esophageal epithelium. Lower drug loadings lead to an increase on the permeability coefficient of LCL. The film containing the drugs blended on a 1:1 (PCL:LCL) proportion has presented the most acceptable cost/benefit ratio. Hence, it was chosen for further investigations. Increasing the total amount of drug in the film from 12.5 to 25 mg significantly raised their force and work of mucoadhesion. On the other hand, it have decreased their tensile strength and elastic modulus. The films presented suitable mechanical e mucoadhesive properties for our purposes. Adding the mucoadhesive (comprised by HPMC K100 LV and polycarbophil at 3:1 w.w-1 and PEG400 as plasticizer) and occlusive (Eudragit® S100 and triethyl citrate as plasticizer) layers on the delivery layer has significantly decreased the amount of drug released, permeated and retained on the epithelium from the films. Thereby, both composition and architecture of the patches must be refined in order to improve the hydration of the delivery layer. For the first time it was presented the efficiency of iontophoresis (1 mA.cm-2) on the permeation enhancement of these drug in association from polymeric films. To reach the replacement of infiltrative anesthesia (2% solution, equivalent to 36 mg of drug), the amount of drug permeated from the most promising film (12.5 mg of PCL:LCL 1:1, 3% w.w-1 HPMC K100LV and 30% PEG400 as a function of the mass of mucoadhesive polymer) must be improved in at least 30 folds.
43

Desenvolvimento de filmes mucoadesivos para liberação de fármacos anestésicos na cavidade bucal / Development of mucoadhesive films for anesthetic release in the buccal cavity

Couto, Renê Oliveira do 30 March 2015 (has links)
A anestesia local normalmente precede a maioria dos procedimentos odontológicos. Porém, por ser realizada por processo invasivo (injetável), muitas vezes afugentam o paciente do consultório. Portanto, a substituição do processo invasivo por não invasivo, além de inovador traria diversas vantagens a odontologia i.e., possibilitaria o aprimoramento de procedimentos rotineiros e cirúrgicos devido à provável redução de custos, submissão do paciente, facilidade de aplicação e menores riscos de contaminação e intoxicações. Neste intuito, filmes poliméricos hidrofílicos mono ou trilaminados, compostos pelo polímero mucoadesivo HPMC K100 LV, glicerol ou PEG 400 como plastificantes, e contendo os anestésicos locais cloridratos de prilocaína (PCL) e lidocaína (LCL) em diferentes proporções foram desenvolvidos. Os filmes apresentaram flexibilidade e moldabilidade adequadas, além de uniformidade de massa e teor. Tanto a massa total de fármaco nos filmes (11 - 55 mg/0,64cm2), quanto suas contribuições relativas nas misturas (0 - 100% m.m-1) modularam seus perfis e cinéticas de liberação e permeação, além das quantidades retidas no epitélio esofageal suíno. Quantidades menores dos fármacos conduziram aos maiores coeficientes de permeabilidade do LCL. O filme contendo mistura dos fármacos na proporção 1:1 (PCL:LCL) apresentou a melhor relação custo/benefício e foi escolhida para a continuidade dos estudos. O aumento na massa total de fármaco nos filmes de 12,5 para 25 mg aumentou significativamente sua força e trabalho de mucoadesão, mas reduziu sua resistência à tração e módulo de elasticidade. Os filmes apresentaram propriedades mecânicas e de mucoadesão adequadas para a finalidade proposta. A adição de camadas oclusiva (composta por Eudragit® S100 e trietil citrato como plastificante) e mucoadesiva (composta por HPMC K100 LV e policarbofil na proporção 3:1 m.m-1 e PEG 400 como plastificante) aos filmes reduziu significativamente as quantidades dos fármacos liberadas, permeadas e retidas no epitélio e, portanto, a composição e arquitetura dos patches trilaminados deve ser aprimorada de modo a favorecer a hidratação da camada de liberação. Pela primeira vez foi demonstrada a eficiência da técnica de iontoforese (1 mA.cm-2) na promoção da permeação destes fármacos em associação a partir de filmes poliméricos. Para que possa substituir a anestesia injetável (solução a 2%, equivalente a 36 mg de fármaco), a permeação dos fármacos a partir do filme mais promissor (12,5 mg de PCL:LCL 1:1, 3% m.m-1 HPMC K100LV e 30% PEG400 em função da massa de polímero mucoadesivo) deve ser aumentada em pelo menos 30 vezes. / Local anesthesia typically precedes the majority of dental procedures. However, due to be performed using an invasive process (injection), often it scares the patient out from the dentist office. Accordingly, besides its innovative character, the replacement of the painful injection by a noninvasive process might bring several advantages to the dentistry field. It might enable the improvement of routinely and surgical procedures as a function of cost saving, patient compliance, ease of application and lowering the risk of contamination and intoxication. In this pursuit, we developed hydrophilic polymeric films comprised by one or three layers, comprised by the mucoadhesive polymer HPMC K100 LV, glycerol or PEG 400 as plasticizers, and containing the local anesthetic drugs prilocaine (PCL) and lidocaine (LCL) hydrochloride in different proportions. The films showed suitable flexibility and plasticity, besides uniformities of mass and content. Both the total mass of drugs in the films (11 - 55 mg/0.64 cm2), and their relative contribution in the mixtures (0 - 100% w.w-1) have modulated their profiles and kinetics of both delivery and permeation, as well as their amount retained in the porcine esophageal epithelium. Lower drug loadings lead to an increase on the permeability coefficient of LCL. The film containing the drugs blended on a 1:1 (PCL:LCL) proportion has presented the most acceptable cost/benefit ratio. Hence, it was chosen for further investigations. Increasing the total amount of drug in the film from 12.5 to 25 mg significantly raised their force and work of mucoadhesion. On the other hand, it have decreased their tensile strength and elastic modulus. The films presented suitable mechanical e mucoadhesive properties for our purposes. Adding the mucoadhesive (comprised by HPMC K100 LV and polycarbophil at 3:1 w.w-1 and PEG400 as plasticizer) and occlusive (Eudragit® S100 and triethyl citrate as plasticizer) layers on the delivery layer has significantly decreased the amount of drug released, permeated and retained on the epithelium from the films. Thereby, both composition and architecture of the patches must be refined in order to improve the hydration of the delivery layer. For the first time it was presented the efficiency of iontophoresis (1 mA.cm-2) on the permeation enhancement of these drug in association from polymeric films. To reach the replacement of infiltrative anesthesia (2% solution, equivalent to 36 mg of drug), the amount of drug permeated from the most promising film (12.5 mg of PCL:LCL 1:1, 3% w.w-1 HPMC K100LV and 30% PEG400 as a function of the mass of mucoadhesive polymer) must be improved in at least 30 folds.
44

Développement de microparticules bioadhésives pour l'administration vaginale de probiotiques / Development of bioadhesive microparticles for vaginal use of probiotics

Pliszczak, Dorothée 23 November 2011 (has links)
Lors d’infections vaginales, divers pathogènes se développent au détriment de la flore locale. L’utilisation de lactobacilles en traitement prophylactique et/ou curatif pourrait pallier ce problème. Le but de ce travail de thèse a été de développer des microparticules mucoadhésives à base de pectine et d’acide hyaluronique (HA) pour la libération intravaginale de probiotiques. Quatre souches probiotiques ont été associées à des prébiotiques afin d’obtenir un effet symbiotique. Les microparticules ont été formulées par émulsification-gélification ionique. Dans un premier temps, l’étude de l’influence de différents paramètres de procédé et de formulation a permis de définir les conditions opératoires pour l’obtention de microparticules d'environ 140 µm de diamètre encapsulant des probiotiques viables. Puis, les propriétés mucoadhésives des microparticules ont été évaluées in-vitro et ex-vivo par des mesures rhéologiques en mode dynamique et par des tests d’indentation. La présence d’HA entraine une augmentation importante du pouvoir bioadhésif des particules. Enfin, ces microparticules ont été incorporées dans des comprimés par un procédé de granulation humide. L’encapsulation des bactéries permet leur protection lors du procédé de compression. De plus, contrairement aux formes classiques d'administration des probiotiques, les microparticules permettent d'obtenir un profil de libération prolongée des bactéries sur environ 10h contre 1h dans le cas d’un comprimé comportant des probiotiques non encapsulés. Un début de prolifération bactérienne s’opère entre 16 et 24 heures. Le comprimé ainsi développé est tout-à-fait adapté à une application vaginale / More than 300 millions of women around the world have urinary or vaginal infections, including yeast vaginitis and bacterial vaginosis. Vaginal use of probiotics offers a potential alternative approach to health restoration and maintenance of the vaginal microflora. Moreover, prebiotics may be combined with probiotics to obtain a symbiotic effect. The aim of this work was to develop pro- and pre-biotics-loaded bioadhesive microparticles by using pectin and hyaluronic acid (HA). Four probiotic strains classically used in vaginal applications and one prebiotic have been selected. Microparticles were produced by emulsification/gelation method using calcium as cross-linking agent. The study of process and formulation parameters allowed obtaining microparticles with a mean diameter of 140 µm which encapsulated between 1010 to 1011 cfu/g of microparticles. Their mucoadhesive properties have been proved both by rheological and indentation measurements in in-vitro and ex-vivo conditions. Moreover, results have shown that HA addition in pectin solutions enhanced the bioadhesive properties of the gel-based microparticles. Afterwards, microparticles have been incorporated inside tablet by wet granulation. Microencapsulation of probiotics allowed protecting them during the compression process. The kinetic release of probiotics studies in in-vitro conditions exhibited a sustained release profile for 10 hours against 1h for unencapsulated probiotics. A beginning of probiotic strain proliferation was observed between 16 to 24 hours. The developed tablet is well-suited to vaginal application
45

Polymer Gels as Pharmaceutical Dosage Forms : Rheological Performance and Physicochemical Interactions at the Gel-Mucus Interface for Formulations Intended for Mucosal Drug Delivery

Hägerström, Helene January 2003 (has links)
<p>Drug delivery to the nasal and ocular mucosa faces several obstacles. One of these is from the effective clearance mechanisms present in the nose and eye. Polymer gels with suitable rheological properties can facilitate the absorption of poorly absorbed drugs by increasing the contact time of the drug with the mucosa. This has been attributed to the rheological and mucoadhesive properties of the gel. The main objective of this thesis was to investigate the importance of these features for the anticipated in vivo contact time, here exemplified by the ocular and nasal routes of administration.</p><p>The in situ gelling polymer gellan gum was found to have a favourable rheological and in vivo performance. When administered in the nasal cavity of rats, a gel was formed that could remain at the site of administration for up to 4 hours. In addition, the epithelial uptake and transfer of a 3 kDa fluorescein dextran was higher than for a mannitol solution. Therefore, it was concluded that a gellan gum formulation should be a promising strategy for nasal drug delivery.</p><p>The potential mucoadhesive properties of a variety of polymer gels were investigated using a rheological method and by measuring the tensile force required to detach the gel from a mucosa. With both methods the rheological properties of the gel were a determining factor for the results obtained. The rheological method was found to have several limitations. One of these was that a positive response, interpreted as mucoadhesion, was only seen with weak gels. The tensile method could, in contrast, detect strengthening of the mucus only for strong gels. However, this method reflects the in vivo performance of the gel better than the rheological method.</p><p>Finally, dielectric spectroscopy was explored as a tool for investigating the likelihood of intimate surface contact between the gel and the mucus layer. This novel approach involved determining the ease with which a charged particle can pass the gel-mucus interface layer, and may enable the study of the events at the interface closer to the molecular level, than is possible with the rheological and tensile strength methods.</p>
46

Polymer Gels as Pharmaceutical Dosage Forms : Rheological Performance and Physicochemical Interactions at the Gel-Mucus Interface for Formulations Intended for Mucosal Drug Delivery

Hägerström, Helene January 2003 (has links)
Drug delivery to the nasal and ocular mucosa faces several obstacles. One of these is from the effective clearance mechanisms present in the nose and eye. Polymer gels with suitable rheological properties can facilitate the absorption of poorly absorbed drugs by increasing the contact time of the drug with the mucosa. This has been attributed to the rheological and mucoadhesive properties of the gel. The main objective of this thesis was to investigate the importance of these features for the anticipated in vivo contact time, here exemplified by the ocular and nasal routes of administration. The in situ gelling polymer gellan gum was found to have a favourable rheological and in vivo performance. When administered in the nasal cavity of rats, a gel was formed that could remain at the site of administration for up to 4 hours. In addition, the epithelial uptake and transfer of a 3 kDa fluorescein dextran was higher than for a mannitol solution. Therefore, it was concluded that a gellan gum formulation should be a promising strategy for nasal drug delivery. The potential mucoadhesive properties of a variety of polymer gels were investigated using a rheological method and by measuring the tensile force required to detach the gel from a mucosa. With both methods the rheological properties of the gel were a determining factor for the results obtained. The rheological method was found to have several limitations. One of these was that a positive response, interpreted as mucoadhesion, was only seen with weak gels. The tensile method could, in contrast, detect strengthening of the mucus only for strong gels. However, this method reflects the in vivo performance of the gel better than the rheological method. Finally, dielectric spectroscopy was explored as a tool for investigating the likelihood of intimate surface contact between the gel and the mucus layer. This novel approach involved determining the ease with which a charged particle can pass the gel-mucus interface layer, and may enable the study of the events at the interface closer to the molecular level, than is possible with the rheological and tensile strength methods.
47

Sistemas precursores de cristais líquidos mucoadesivos para administração vaginal de hipericina associados à terapia fotodinâmica no tratamento da candidíase vulvovaginal / Mucoadesive liquid crystal precursor systems for vaginal administration of hypericin associated with photodynamic therapy in the treatment of vulvovaginal candidiasis

Araújo, Patricia Rocha de 20 September 2018 (has links)
Submitted by Patricia Rocha de Araújo (patriciarocha39@hotmail.com) on 2018-10-15T01:56:34Z No. of bitstreams: 1 Dissertação Patricia Rocha out 2018.pdf: 3514360 bytes, checksum: 9b0fea77694a33ed0ae69da788c5a4a2 (MD5) / Approved for entry into archive by Maria Irani Coito (irani@fcfar.unesp.br) on 2018-10-16T20:37:01Z (GMT) No. of bitstreams: 1 araujo_pr_me_arafcf.pdf: 3514379 bytes, checksum: dffaf731be630bbca5063c79b406b6ae (MD5) / Made available in DSpace on 2018-10-16T20:37:01Z (GMT). No. of bitstreams: 1 araujo_pr_me_arafcf.pdf: 3514379 bytes, checksum: dffaf731be630bbca5063c79b406b6ae (MD5) Previous issue date: 2018-09-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A candidíase vulvovaginal (CVV) é uma doença causada por espécies do gênero Candida spp. no trato genital inferior feminino que afeta um grande número de mulheres em todo mundo. Porém o uso sistêmico de fármacos causa muitas reações adversas e as formulações tópicas possuem um baixo tempo de retenção na mucosa vaginal devido à diluição dos sistemas na cavidade vaginal. Esse estudo propõe uma terapia antifúngica alternativa empregando sistemas precursores de cristais líquidos mucoadesivos (SPCLM) para a liberação de hipericina (HIP), um potente fotossensibilizador isolado de plantas do gênero Hipericum com e sem o emprego da terapia fotodinâmica (TFD). O sistema visa aumentar o tempo de permanência da formulação, bem como reduzir o número de aplicações e a quantidade de fármaco empregada. O emprego da TFD, por sua vez, se faz como uma forma de diminuir a resistência pelos microrganismos. Observou-se a formação de sistemas isotrópicos no sistema constituído por 30% da fase oleosa constituída por ácido oleico e colesterol na razão de 7:1, 40% de Procetyl AWS como tensoativo e 30% de uma dispersão de poloxamer à 16% empregando as técnicas de microscopia de luz polarizada e espalhamento de raios-X a baixo ângulo. Após a introdução de três diferentes concentrações de fluido vaginal simulado FVS (30, 50 e 100%), as formulações resultantes passaram a apresentar anisotropia e picos característicos de fase lamelar. Análises das propriedades mecânicas, reológicas e mucoadesivas das formulações indicaram que a organização e a mucoadesão dos sistemas aumentaram à medida que a quantidade de FVS aumentou. Os ensaios de validação da metodologia analítica para quantificação de HIP indicaram que o método é aceitável segundo agências regulatórias. Os testes de liberação in vitro demonstraram perfil de liberação sustentada da HIP provavelmente devido à sua alta afinidade pelos componentes da fase oleosa dos sistemas de liberação. Além disso, os SPCLM causaram aumento da retenção e baixa permeação da HIP em mucosa suína. Ensaios microbiológicos indicaram que a HIP é um agente eficaz para inativação das leveduras de Candida albicas com emprego da TFD, porém os SPCLM com HIP não potencializaram a ação antifúngica deste composto, possivelmente devido ao longo período necessário para sua liberação. Os testes de citotoxicidade indicaram que todas as formulações apresentam baixa toxicidade, porém os sistemas com hipericina incorporada apresentaram maior toxicidade para células tumorais L292. Ensaios in vivo do sistema em modelo de CVV são necessários para comprovar a viabilidade do sistema desenvolvido. / Vulvovaginal candidosis (VVC) is a disease induced by Candida strains in the female genital tract that affects a great number of women worldwide. However, systemic drugs cause many adverse reactions. Also, currently employed topical dosage forms present low retention times due to their dilution in vaginal fluids. This study proposes an alternative antifungal therapy through the development of liquid crystalline precursor systems (LCPS) for hypericin release, a potent photosensitizer isolated from Hipericum plants with and without photodynamic inactivation (PDI). The developed system aims to increase the residence time of the formulations, as well as decrease the number of applications and the amount of drug. Photodynamic therapy was used to reduce microorganism resistance. Polarized light microscopy and Small-Angle X-Ray Scattering confirmed the formation of an isotropic system composed of 30% of oil phase containing oleic acid and cholesterol in (ratio of 7:1). After addition of three different concentrations of simulated vaginal fluid -SVF (30, 50 and 100%), the resultant formulations presented anisotropy and characteristic peaks of lamellar phases. Mechanical, rheological and mucoadhesive assays indicated the formation of long-range ordering systems as the amount of SVF increased. Drug validation assays indicated that the method is aceptable for hypericin quantification according to regulatory agencies. In vitro drug release assays exhibited a sustained release profile probably due to the high affinity between HIP and the oily phase components. In addition, the LCPS lead to poor permeability and enhanced retention of HIP in the porcine mucosa. Microbiological assays pointed out that HIP effectively inactivated Candida albicans yeasts with PTD, however the HIP loaded LCPS did not potentiate the antifungal activity of HIP, probably due to the long period for HIP release. Cytotoxic tests indicated that all formulations presented low toxicity, however the HIP loaded presented higher toxicity to L292 tumor cells. In vivo assays should be performed to confirm the viability of the developed system. / 001
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Formulation, développement et validation de systèmes particulaires d'insuline en vue de leur administration par voie orale / Formulation, development and validation of insulin loaded particulate systems for their oral administration

Diop, Mouhamadou 18 December 2015 (has links)
Administration par voie orale.L’insulinothérapie permet aux diabétiques de réguler leur glycémie. La thèse s’inscrit dans le projet ORAIL Bis qui vise à développer un système d’administration orale d’insuline basé sur la double encapsulation de l’insuline. Le vecteur développé est composé d’une gélule contenant des particules (NP) d’insuline formulées à partir de chitosane (CS) par coacervation complexe ou d’acide (lactique-co-glycolique) (PLGA) par double émulsion. Les objectifs de la thèse sont de stabiliser les NP de chitosane par réticulation et lyophilisation, augmenter la biodisponibilité des NP de PLGA par mucoadhésion, les transposer à l’échelle industrielle. Les résultats ont montré que la combinaison des deux approches permet de réduire la taille des NP de CS, de maintenir une charge positive, de leur conférer une stabilité et une bioefficacité. La mucoadhésion n’a pas permis d’augmenter la biodisponibilité des NP de PLGA. Une charge négative permet d’améliorer leur efficacité biologique et sont transposable à échelle industrielle. L’encapsulation de ces NP dans une gélule a permis de valider in vivo le concept de double encapsulation de l’insuline. / Insulinotherapy helps diabetics to regulate their glycaemia. This thesis is part of the ORAIL Bis project which aims to develop an oral insulin delivery system based on the double encapsulation of insulin. The developed vector is composed of a capsule containing insulin loaded particles (NPs) formulated with chitosan (CS) by complex coacervation or poly (lactic-co-glycolic) acid (PLGA) by double emulsion solvent evaporation. The objectives of the thesis are to stabilize chitosan NPs by crosslinking and freeze-drying, increase the bioavailability of NPs PLGA by mucoadhesion and transpose them to the industrial scale. Results showed that the combination of both strategies reduces the size of CS NPs, maintain a positive charge, give them stability and bioefficacy. Mucoadhesion failed to increase the bioavailability of PLGA NPs. A negative charge allows to improve their biological efficacy and are transposed to industrial scale. The encapsulation of these NPs in an alginate capsule allowed to validate in vivo the concept of double encapsulation of insulin.
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Systèmes nanostructurés décorés par du chitosane pour la délivrance buccale de la curcumine / Nanostructured systems coated with chitosan for buccal curcumin delivery

Mazzarino, Leticia 24 April 2013 (has links)
Cette étude décrit le développement de systèmes nanostructurés muco-adhésives, qui comprennent les nanoparticules décorées avec du chitosane et les films contenant des nanoparticules, visant la libération buccale de la curcumine. Deux différents systèmes de nanoparticules ont été développés: les nanoparticules de polycaprolactone (PCL) et les nanoparticules xyloglucane-bloc-polycaprolactone (XGO-b-PCL). Les nanoparticules de PCL ont été préparées par la technique de nanoprécipitation, alors que les nanoparticules XGO-b-PCL ont été préparées par la méthode du co-solvant. Les deux systèmes colloïdaux ont montré une forme sphérique et distribution monodisperse de particules. La décoration des nanoparticules avec du chitosane a été confirmée en mesurant la taille des particules et le potentiel zêta. Les études de la diffusion dynamique de la lumière (DLS) montrent un rayon hydrodynamique autour de 100 nm pour les nanoparticules de PCL et 50 nm pour les nanoparticules de XGO-b-PCL. Les suspensions de nanoparticules chargées en curcumine présentent des valeurs d'efficacité d'encapsulation proche de 100 %, et un taux moyen de principe actif autour de 450 μg/mL et 180 μg/mL pour les nanoparticules de PCL et XGO-b-PCL, respectivement. Les systèmes de nanoparticules ont aussi été caractérisées par la technique d'analyse du suivi des nanoparticules (NTA) et microscopie électronique à transmission (MET). Les propriétés mucoadhésives des nanoparticules ont été évaluées en mesurant les interactions de ces systèmes avec la glycoprotéine mucine (mucine sous-maxillaire bovine, BSM) par diffusion dynamique de la lumière (DLS), microbalance à cristal de quartz avec la mesure de dissipation d'énergie (QCM-D) et résonance plasmonique de surface (SPR). Toutes les nanoparticules décorées avec du chitosane ont démontré une excellente capacité d'interaction avec la mucine via de forces électrostatiques formées entre les groupes amines du polysaccharide et les groupes chargés négativement de la glycoprotéine, indiquant leur potentiel comme vecteurs mucoadhésives de médicaments. Les nanoparticules PCL ont aussi été caractérisées en termes de perméabilité et de rétention de curcumine à travers la muqueuse oesophagienne de porc. La rétention de concentrations de curcumine dans la muqueuse indique la possibilité d'obtention des effets locaux sur la surface muqueuse. Les études in vitro ont montré que les nanoparticules de PCL et XGO-b-PCL contenant la curcumine ont présenté une activité cytotoxique plus petite par rapport à la curcumine libre. Les nanoparticules de PCL contenant de la curcumine ont aussi démontré une activité antimicrobienne contre Candida albicans, ce qui suggère leur potentiel utilisation dans le traitement des infections fungiques. Les films mucoadhésifs contenant des nanoparticules ont été préparés par la technique de « casting », après l'incorporation des nanoparticules de PCL dans les solutions de chitosane plastifié. Les films obtenus en utilisant du chitosane de moyenne et haute masse molaire sont homogènes et flexibles. Les nanoparticules de PCL chargées de curcumine étaient uniformément distribuées sur les surfaces des films, comme le montrent les images de microscopie à force atomique (AFM) et de microscopie électronique à balayage de haute résolution (MEB-FEG). L'analyse par MEB-FEG des sections transversales des films a démontré la présence de nanoparticules à l'intérieur des films. En plus, les films ont montré un taux important d'hydratation en milieu salivaire et une libération contrôlée-prolongée de la curcumine. Par conséquent, les résultats obtenus indiquent que les systèmes mucoadhésives développés, nanoparticules décorées avec du chitosane et films contenant des nanoparticules, offrent une nouvelle stratégie pour la libération buccale de la curcumine, et sont potentiellement intéressant dans des applications de traitement locaux des maladies de la cavité orale. / This study describes the development of mucoadhesive nanostructured systems, including chitosan-coated nanoparticles and films containing nanoparticles, aiming the buccal delivery of curcumin. Two different systems of nanoparticles were developed: polycaprolactone (PCL) nanoparticles and xyloglucan-block-polycaprolactone (XGO-b-PCL) nanoparticles. PCL nanoparticles were prepared by the nanoprecipitation technique, while XGO-b-PCL nanoparticles were prepared by the co-solvent method. Both colloidal systems displayed spherical shape and monodisperse distribution of particles. The decoration of nanoparticles with chitosan was confirmed by particle size and zeta potential measurements. Dynamic light scattering (DLS) studies shown hydrodynamic radius around of 100 nm for PCL nanoparticles, and 50 nm for XGO-b-PCL nanoparticles. Curcumin-loaded nanoparticle suspensions exhibited encapsulation efficiency values close to 100 %, and a mean drug content about of 450 μg/mL and 180 μg/mL for PCL and XGO-b-PCL nanoparticles, respectively. Nanoparticle systems were also characterized by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). The mucoadhesive properties of nanoparticles were evaluated by monitoring the interactions of these systems with glycoprotein mucin (bovine submaxillary mucin, BSM) by dynamic light scattering (DLS), quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR). All chitosan-coated nanoparticles demonstrate excellent ability to interact with mucin though electrostatic forces formed between amino groups of polysaccharide and negatively charged groups of glycoprotein, indicating their potential as mucoadhesive drug carriers. PCL nanoparticles were also characterized in terms of curcumin permeability and retention across the porcine esophageal mucosa. Amount of curcumin retained in the mucosa highlights the possibility of application for obtaining local effects on the mucosal surface. In vitro studies demonstrated that curcumin into copolymer nanoparticles showed reduced cytotoxicity when compared to free drug. Curcumin-loaded PCL nanoparticles also exhibited antimicrobial activity against Candida albicans strains, suggesting their potential use in the treatment of fungal infections. Mucoadhesive films containing nanoparticles were prepared using the casting technique, after the incorporation of PCL nanoparticles in plasticized chitosan solutions. Films obtained using medium and high molar mass chitosan showed to be homogeneous and flexible. Curcumin-loaded PCL nanoparticles were uniformly distributed on the films surface, as evidenced by atomic force microscopy (AFM) and high-resolution scanning electron microscopy (FEG-SEM) images. Analyses of films cross sections by FEG-SEM demonstrate the presence of nanoparticles inside the films. In addition, films showed good rate of hydration in saliva medium, and in vitro prolonged-controlled delivery of curcumin. Therefore, the results obtained indicate that the developed mucoadhesive systems, chitosan-coated nanoparticles and films containing nanoparticles, offer a novel strategy to buccal curcumin delivery and have potential applications in the local treatment of oral cavity disease.
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Desenvolvimento de sistemas precursores de fase cristalina para administração intrabolsa periodontal / Development of precursors crystalline phase for intra pocket periodontal administration.

Kariane Mendes Nunes 21 December 2012 (has links)
A doença periodontal é uma patogenia que afeta as estruturas de suporte dos dentes com formação da bolsa periodontal, e caso não tratada, em estágios mais avançados o periodonto é destruído, ocasionando perda do dente. O tratamento concerne em duas etapas, à remoção mecânica do biofilme e cálculo dentário por raspagem e alisamento radicular e utilização de antimicrobianos. Ainda é comum a utilização de antimicrobiano de ação sistêmica, embora, tenha eficácia reduzida e frequentes efeitos adversos. Em face disto, justifica-se o desenvolvimento de sistemas de liberação sustentada de fármaco intrabolsa periodontal a fim de sanar os inconvenientes da terapia sistêmica. Contudo, aspectos como espaço anatomofisiológico e fluído gengival crevicular intrínsecos à bolsa, são limitações pertinentes durante o desenvolvimento. Portanto, este trabalho teve como objetivo desenvolver sistemas e formulações precursoras de fase líquido cristalina baseados em monolinoleato de glicerila (MLG) e cremophor (CREM) com gelificação in situ em fase líquido cristalina. Por meio de planejamento fatorial 32 foram obtidos 9 sistemas sem adição de fármaco e 9 formulações contendo metronidazol com diferentes razões de MLG/CREM e %H2O. Quando caracterizados por microscopia de luz polarizada e espalhamento de raios-X a baixo ângulo, os sistemas e formulações com menor razão MLG/CREM e conteúdos de água de 5, 10 e 15% apresentaram organização micelar isotrópica. Eles também apresentaram rápida erosão no ensaio de captação de água, inviabilizando sua transição para mesofase. Os sistemas e formulações com média e alta razão MLG/CREM e conteúdos de água de 5, 10 e 15% apresentaram coexistência de fases em transição líquido cristalina. Apresentaram rápida captação de água com transição para fase cúbica. Contudo, com exceção do sistema e formulação com alta razão MGL/CREM e 15% de água, os demais sistemas e formulações, apresentaram propriedades de fluxo ideais para fácil aplicação por seringa acoplada a agulha, e comportamento viscoelástico adequado para promover espalhabilidade e retenção no interior da bolsa. Os sistemas e formulações com média e alta razão de MLG/CREM apresentaram melhor mucoadesão. Dentre as formulações, apenas a com média razão de GML/CREM e 5% de água, apresentou perfil bi-modal de liberação mantendo concentrações de metronidazol acima do MIC por 6 dias, característica desejável para sistemas de liberação intrabolsa periodontal. Portanto, todos os resultados advogam a favor desta formulação como potencial candidata ao emprego clínico como sistema de liberação de fármaco intrabolsa periodontal. / Periodontal disease is a chronic infection that affects the structural supports of the tooth with periodontal pocket formation. If untreated, the periodontium may be destroyed, which can cause the tooth loss in the latest stages of the disease. The treatment for this infection comprises two stages, the mechanical removal of plaque and calculus by scaling and root planing and the use of antimicrobials. It is still common to use systemic antimicrobials, even though it has a reduced efficacy and frequent adverse effects. For the reason, justified the development of systems for sustained release of drug intra-pocket periodontal in order to solve the drawbacks of systemic therapy. The main limitations for the development of these systems are the anatomical and physiological aspects of the periodontal pocket, which includes the limited size and the depth area and the natural irrigate flow of the gingival crevice fluid (GCF). So, this study aimed to develop precursor liquid crystalline systems and formulations based on glyceryl monolinoleate (GML) and cremophor (CREM), with in situ gelation to liquid crystalline phases. Through a 32 factorial design 9 systems without drug and 9 formulations containing metronidazole were obtained. Different ratios of GML / CREM and water percentage were evaluated. When characterized by Small-Angle X-ray Scattering and Polarized Light Microscopy, lower ratio GML / CREM with 5, 10 and 15% H2O produce isotropic micellar organization. They also showed high erosion during water uptake, thus, precluding in situ crystalline transition. Medium and high ratio GML / CREM with 5, 10 and 15% H2O indicated the coexistence of regions in transition to the crystalline phase. They showed characteristic peaks of cubic phases, rapid water uptake, higher viscosity and increased mucoadhesion. Moreover, with the exception of the formulation containing high ratio and high water content, other systems and formulations with medium ratio GML / CREM and 5, 10, 15% of water and high ratio and 5 and 10% of water had flow properties ideal for easy application through needle fitted syringes, viscoelastic behavior appropriate to promote spreadability and might favor retention within the periodontal pocket. However, only the formulation with higher ratio and the lowest water content presented a bimodal release profile of metronidazole, maintaining concentrations above the MIC for 5 days, with the release of 100% of the drug added to the formulation. These are desirable features for delivery systems designed for periodontal pockets. Therefore, all results advocate in favor of the formulation with high ratio of GML / CREM and 5% of water as a potential candidate for clinical use as drug delivery system for the periodontal pocket.

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