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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.
31

Cellulose Esters and Cellulose Ether Esters for Oral  Drug Delivery Systems

Arca, Hale Cigdem 01 November 2016 (has links)
Amorphous solid dispersion (ASD) is a popular method to increase drug solubility and consequently poor drug bioavailability. Cellulose ω-carboxyesters were designed and synthesized specifically for ASD preparations in Edgar lab that can meet the ASD expectations such as high Tg, recrystallization prevention and pH-triggered release due to the free -COOH groups. Rifampicin (Rif), Ritonavir (Rit), Efavirenz (Efa), Etravirine (Etra) and Quercetin (Que) cellulose ester ASDs were investigated in order to increase drug solubility, prevent release at low pH and controlled release of the drug at small intestine pH that can improve drug bioavailability, decrease needed drug content and medication price to make it affordable in third world countries, and extent pill efficiency period to improve patient quality of life and adherence to the treatment schedule. The studies were compared with cellulose based commercial polymers to prove the impact of the investigation and potential for the application. Furthermore, the in vitro results obtained were further supported by in vivo studies to prove the significant increase in bioavailability and show the extended release. The need of new cellulose derivatives for ASD applications extended the research area, the design and synthesis of a new class of polymers, alkyl cellulose ω-carboxyesters for ASD formulations investigated and the efficiency of the polymers were summarized to show that they have the anticipated properties. The polymers were synthesized by the reaction of commercial cellulose alkyl ethers with benzyl ester protected, monofunctional hydrocarbon chain acid chlorides, followed by removal of protecting group using palladium hydroxide catalyzed hydrogenolysis to form the alkyl cellulose wcarboxyalkanoate. Having been tested for ASD preparation, it was proven that the polymers were efficient in maintaining the drug in amorphous solid state, release the drug at neutral pH and prevent the recrystallization for hours, as predicted. / Ph. D.
32

Studium struktury a segmentové dynamiky farmaceutických materiálů na bázi tuhých disperzí léčiv v polymerních matricích pomocí NMR spektroskopie pevného stavu. / Solid-state NMR study of structure and segmental dynamics of pharmaceutical materials based on the solid dispersions of drugs in polymer matrices.

Policianová, Olívia January 2014 (has links)
Highly-exact structural characterization is the crucial step in the development and manufacturing process of pharmaceutical materials. Their structural composition is, however, often very complex and hardly identifiable. The eligible way for obtaining definite structural interpretation of these systems appears the high-resolution solid-state nuclear magnetic resonance (ssNMR) spectroscopy. For this purpose the reliable tool - the ssNMR toolbox for comprehensive characterization of various pharmaceutical solids is described. The rigorous optimization of ssNMR techniques is carried out on enormous number of measured samples containing active pharmaceutical ingredients (APIs) with systems ranging from APIs formulated in solid dispersions to pure forms revealing extensive molecular disorder. In this study the influence of polymeric matrix on the creation of solid dispersion type susceptible for finely tuned controlled drug release is likewise discussed. The distinction between variable structural alignments of API molecules in 3D dimension of complicated pharmaceutical solids is allowed via simple strategy - factor analysis applied to hardly describable ssNMR spectra (13 C CP/MAS NMR and 19 F MAS NMR). The results of this ssNMR investigation contribute to better understanding of solid dispersion...
33

Desenvolvimento e caracterização de dispersões sólidas de nimodipino empregando PEG 6000 ou Poloxamer 407 / Development and characterization of nimodipine solid dispersions of PEG 6000 or Poloxamer 407

Kreidel, Rogério Nepomuceno 11 March 2010 (has links)
O nimodipino é um bloqueador de canais de cálcio usado principalmente na terapia da hemorragia subaracnóidea e no tratamento de distúrbios cognitivos. É praticamente insolúvel em água e, pelo Sistema de Classificação Biofarmacêutica (SCB), é qualificado como classe II e, portanto, sua dissolução é etapa limitante da absorção, podendo apresentar problemas de biodisponibilidade. Assim, o objetivo do trabalho foi desenvolver e caracterizar dispersões sólidas de nimodipino, obtidas com os carreadores PEG 6000 ou Poloxamer 407 e compará-las quanto à melhoria na solubilidade e na dissolução do nimodipino. As dispersões sólidas foram obtidas pelos métodos de fusão e de evaporação do solvente e foram caracterizadas pelas técnicas de calorimetria exploratória diferencial (DSC), espectroscopia de absorção na região do infravermelho (FT-IR) e difração de raios-X, cujos resultados comprovaram a obtenção das dispersões sólidas. As características de solubilidade e de dissolução do nimodipino nas dispersões sólidas e em misturas físicas foram comparadas. As dispersões sólidas contendo poloxamer 407 apresentaram maior eficiência em melhorar a solubilidade e a velocidade de dissolução do nimodipino, o que pode ser explicado pelo seu efeito tensoativo. O aumento da solubilidade das dispersões sólidas preparadas com PEG (DSPEG-10 = 13,2 g.mL-1) foi significativamente maior que aquele devido às misturas físicas de mesma composição (MFPEG-10 = 3,21 g.mL-1) que, por sua vez, apresentaram solubilidade maior que a do fármaco (2,19 g.mL-1). O mesmo ocorreu com a eficiência de dissolução dessas preparações (DSPEG-10 = 69,11% , MFPEG-10 = 15,61% e nimodipino = 11,68%). Maior incremento da solubilidade foi obtido com a dispersão sólida produzida pelo método de evaporação do solvente contendo poloxamer 407 como carreador (SOLVP407-10 = 75,61 g.mL-1). / Nimodipine is a calcium blocker, used in prevention and treatment of ischaemic neurological deficits after aneurismal subarachnoid hemorrhage and cognitive deficit. It exhibits a low solubility in water and it is classified as class two in the Biopharmaceutics Classification System (BCS), thereby dissolution is the ratelimiting step in absorption, which impact on bioavailability. Consequently, the objective of this study was to develop and characterize solid dispersions of nimodipine, prepared with PEG 6000 or Poloxamer 407 and to compare them in terms of nimodipine solubility and dissolution. Solid dispersions were obtained by fusion and solvent methods and they were characterized by differential scanning calorimetry (DSC), infra red spectroscopy (FT-IR) and X-ray diffraction, where results confirmed the formation of solid dispersions. Solubility and dissolution characteristics of nimodipine in solid dispersions and physical mixtures were compared. Solid dispersions containing poloxamer 407 showed better efficiency than PEG in increasing solubility and dissolution rate of nimodipine, and it can be explained due to its surfactant activity. The solubility results obtained with solid dispersions prepared with PEG 6000 (DSPEG-10 = 13,2 g.mL-1) were better than physical mixtures with the same composition (MFPEG-10 = 3,21 g.mL-1) which, in turn, showed increased solubility compared with nimodipine (2,19 g.mL-1). Similar results were observed for dissolution efficiency (DSPEG-10 = 69,11% , MFPEG-10 = 15,61% and nimodipine = 11,68%). The best solubility result was obtained by the formulation prepared by the solvent method with poloxamer 407 as carrier (SOLVP407-10 = 75,61 g.mL-1).
34

Desenvolvimento e caracterização de dispersões sólidas de nimodipino empregando PEG 6000 ou Poloxamer 407 / Development and characterization of nimodipine solid dispersions of PEG 6000 or Poloxamer 407

Rogério Nepomuceno Kreidel 11 March 2010 (has links)
O nimodipino é um bloqueador de canais de cálcio usado principalmente na terapia da hemorragia subaracnóidea e no tratamento de distúrbios cognitivos. É praticamente insolúvel em água e, pelo Sistema de Classificação Biofarmacêutica (SCB), é qualificado como classe II e, portanto, sua dissolução é etapa limitante da absorção, podendo apresentar problemas de biodisponibilidade. Assim, o objetivo do trabalho foi desenvolver e caracterizar dispersões sólidas de nimodipino, obtidas com os carreadores PEG 6000 ou Poloxamer 407 e compará-las quanto à melhoria na solubilidade e na dissolução do nimodipino. As dispersões sólidas foram obtidas pelos métodos de fusão e de evaporação do solvente e foram caracterizadas pelas técnicas de calorimetria exploratória diferencial (DSC), espectroscopia de absorção na região do infravermelho (FT-IR) e difração de raios-X, cujos resultados comprovaram a obtenção das dispersões sólidas. As características de solubilidade e de dissolução do nimodipino nas dispersões sólidas e em misturas físicas foram comparadas. As dispersões sólidas contendo poloxamer 407 apresentaram maior eficiência em melhorar a solubilidade e a velocidade de dissolução do nimodipino, o que pode ser explicado pelo seu efeito tensoativo. O aumento da solubilidade das dispersões sólidas preparadas com PEG (DSPEG-10 = 13,2 g.mL-1) foi significativamente maior que aquele devido às misturas físicas de mesma composição (MFPEG-10 = 3,21 g.mL-1) que, por sua vez, apresentaram solubilidade maior que a do fármaco (2,19 g.mL-1). O mesmo ocorreu com a eficiência de dissolução dessas preparações (DSPEG-10 = 69,11% , MFPEG-10 = 15,61% e nimodipino = 11,68%). Maior incremento da solubilidade foi obtido com a dispersão sólida produzida pelo método de evaporação do solvente contendo poloxamer 407 como carreador (SOLVP407-10 = 75,61 g.mL-1). / Nimodipine is a calcium blocker, used in prevention and treatment of ischaemic neurological deficits after aneurismal subarachnoid hemorrhage and cognitive deficit. It exhibits a low solubility in water and it is classified as class two in the Biopharmaceutics Classification System (BCS), thereby dissolution is the ratelimiting step in absorption, which impact on bioavailability. Consequently, the objective of this study was to develop and characterize solid dispersions of nimodipine, prepared with PEG 6000 or Poloxamer 407 and to compare them in terms of nimodipine solubility and dissolution. Solid dispersions were obtained by fusion and solvent methods and they were characterized by differential scanning calorimetry (DSC), infra red spectroscopy (FT-IR) and X-ray diffraction, where results confirmed the formation of solid dispersions. Solubility and dissolution characteristics of nimodipine in solid dispersions and physical mixtures were compared. Solid dispersions containing poloxamer 407 showed better efficiency than PEG in increasing solubility and dissolution rate of nimodipine, and it can be explained due to its surfactant activity. The solubility results obtained with solid dispersions prepared with PEG 6000 (DSPEG-10 = 13,2 g.mL-1) were better than physical mixtures with the same composition (MFPEG-10 = 3,21 g.mL-1) which, in turn, showed increased solubility compared with nimodipine (2,19 g.mL-1). Similar results were observed for dissolution efficiency (DSPEG-10 = 69,11% , MFPEG-10 = 15,61% and nimodipine = 11,68%). The best solubility result was obtained by the formulation prepared by the solvent method with poloxamer 407 as carrier (SOLVP407-10 = 75,61 g.mL-1).
35

Dispers?es s?lidas de sinvastatina: prepara??o, caracteriza??o, no estado s?lido utilizando t?cnicas emergentes e estudo de estabilidade / Dispers?es s?lidas de sinvastatina: prepara??o, caracteriza??o, no estado s?lido utilizando t?cnicas emergentes e estudo de estabilidade

Vargas, Mara R?bia Winter de 29 May 2014 (has links)
Made available in DSpace on 2014-12-17T14:25:23Z (GMT). No. of bitstreams: 1 MaraRWV_TESE.pdf: 3541177 bytes, checksum: 2415c9163a59f9b397912f22608eefbc (MD5) Previous issue date: 2014-05-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This thesis aimed to assess the increase in solubility of simvastatin (SINV) with solid dispersions using techniques such as kneading (MA), co-solvent evaporation (ES), melting carrier (FC) and spray dryer (SD). Soluplus (SOL), PEG 6000 (PEG), PVP K-30 (PVP) e sodium lauryl sulphate (LSS) were used as carriers. The solid dispersions containing PEG [PEG-2(SD)], Soluplus [SOL-2(MA)] and sodium lauryl sulphate [LSS-2(ES)] were presented with a greater increase in solubility (5.02, 5.60 and 5.43 times respectively); analyses by ANOVA between the three groups did not present significant difference (p<0.05). In the phase solubility study, the calculation of the Gibbs free energy (&#916;G) revealed that the spontaneity of solubilisation of SINV occurred in the order SOL>PEG >PVP 75%>LSS, always 80%. The phase diagrams of PEG and LSS presented solubilization stoichiometry of type 1:1 (type AL). The diagrams with PVP and SOL tend to 1:2 stoichiometry (type AL + AP). The stability coefficients (Ks) of the phase diagrams revealed that the most stable reactions occurred with LSS and PVP. The solid dispersions were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), particle size distribution (PSD), near-infrared spectroscopy imaging (NIR-CI) and X-ray diffraction of the powder using the Topas software (PDRX-TOPAS). The solid dispersion PEG-2(SD) presented the greatest homogeneity and the lowest degree of crystallinity (18.2%). The accelerated stability study revealed that the solid dispersions are less stable than SINV, with PEG-2(SD) being the least stable, confirmed by FTIR and DSC. The analyses by PDRX-TOPAS revealed the amorphous character of the dispersions and the mechanism of increasing solubility / Esta tese teve como objetivo avaliar o aumento de solubilidade da sinvastatina (SINV) atrav?s de dispers?es s?lidas utilizando as t?cnicas de malaxagem (MA), evapora??o com co- solvente (ES), fus?o com carreador (FC) e secagem por spray dryer (SD). Foram utilizados os carreadores Soluplus (SOL), PEG 6000 (PEG), PVP K-30 (PVP) e lauril sulfato de s?dio (LSS). As dispers?es s?lidas contendo PEG [PEG-2(SD)], Soluplus [SOL-2(MA)] e lauril sulfato de s?dio [LSS-2(ES)] apresentaram maior aumento de solubilidade (5,02; 5,60 e 5,43 vezes, respectivamente); a an?lise por ANOVA entre os tr?s grupos n?o demonstrou diferen?a significativa (p<0,05). No estudo de solubilidade de fases, o c?lculo da energia livre de Gibbs (&#916;G) revelou que a espontaneidade de solubiliza??o da SINV ocorreu na ordem SOL>PEG >PVP 75%>LSS, sempre a 80%. Os diagramas de fases de PEG e LSS apresentaram estequiometria de solubiliza??o 1:1 (tipo AL). Os diagramas de PVP e SOL possuem uma tend?ncia a estequiometria 1:2 (tipo AL + AP). Os valores de coeficiente de estabilidade (Ks) dos diagramas de fases revelaram que as rea??es mais est?veis ocorreram com LSS e PVP. As dispers?es s?lidas foram caracterizadas atrav?s de infravermelho com transformada de Fourier (FTIR), calorimetria explorat?ria diferencial (DSC), microscopia eletr?nica de varredura (MEV), distribui??o de tamanho de part?cula (DTP), espectroscopia de imagem no infravermelho pr?ximo (NIR-CI) e difratometria de raios X do P? utilizando o software Topas (PDRX-TOPAS). A dispers?o s?lida PEG-2(SD) apresentou a maior homogeneidade e o menor grau de cristalinidade (18,2%). O estudo de estabilidade revelou que as dispers?es s?lidas s?o menos est?veis que SINV, sendo PEG-2(SD) a de menor estabilidade, confirmada por FTIR e DSC. As an?lises por PDRX-TOPAS revelaram a cristalinidade das dispers?es e o mecanismo de aumento de solubilidade
36

Films orodispersibles de tétrabénazine pour l’administration pédiatrique / Pediatric administration of tetrabenazine as orodispersibles films form

Senta-Loys, Zoé 20 December 2016 (has links)
Lors de cette dernière décennie, le développement de formes pharmaceutiques innovantes permettant d'améliorer l'efficacité, la sécurité et l'acceptabilité des médicaments pédiatriques est en pleine croissance. Les films orodispersibles (ODF) appartiennent à ces nouvelles formes galéniques améliorant la compliance des patients. Ils sont constitués d'une matrice de polymère hydrophile dans laquelle un ou des principe(s) actif(s) (PA) sont dissous ou dispersés. Après dépôt de l'ODF sur la langue ou dans la cavité buccale, la matrice se désagrège libérant le PA pour une action locale ou systémique. Dans cette étude, la mise au point d'ODF, par la méthode de coulée/évaporation de solvant a été explorée afin d'administrer un PA d'intérêt en pédiatrie, la tétrabénazine (TBZ). Les caractérisations physicochimiques et biopharmaceutiques des ODF ont mis en évidence une augmentation de la vitesse et du taux de dissolution de la TBZ induit par son état amorphe. Le système constitué d'un support polymère et d'un PA sous forme amorphe peut être assimilé aux dispersions solides amorphes (SD). Les études réalisées démontrent l'importance de la nature du polymère utilisé pour maintenir les propriétés initiales du système dans le temps. La formation de liaisons hydrogène entre la PA étudié et le polymère est un facteur essentiel pour assurer la stabilité des SD. De plus, l'incorporation de cyclodextrines (CD) prolonge l'état amorphe du PA en générant des liaisons hydrogène avec la TBZ et en l'entourant d'une barrière chimique. Cette association favorise la libération du PA par effet synergique améliorant la biodisponibilité. Cette forme innovante représente un intérêt majeur dans l'amélioration de l'observance dans le cadre d'un traitement pédiatrique / During the last decade, various strategies to develop innovating oral dosage forms for pediatric population were investigated in order to improve treatment efficiency, safety and acceptability. Among these new delivery systems, orodispersible films (ODF) present a great potential to enhance patient compliance. In ODF, drug is dissolved or dispersed in a hydrophilic film-forming polymer. Once the ODF is in the mouth, polymeric matrix disintegrates releasing the drug for local or systemic action. In this study, ODF, produced with the solvent casting/evaporation method, were developed to administer a drug of interest for pediatric population, the tetrabetazine (TBZ). Physicochemical and biopharmaceutic characterizations showed that ODF allowed a major improvement of TBZ dissolution profile in simulated saliva, mainly due to the amorphous state of the drug in ODF. ODF were identified as amorphous solid dispersion (SD) composed of both amorphous TBZ and polymer matrix. We demonstrated that the choice of the polymer plays an important role to maintain initial properties of the system and amorphous state stability over the time. H-bonding formation between TBZ and polymer is essential to assure the preservation of TBZ amorphous state. Moreover, the incorporation of cyclodextrins (CD), by generating H-bonding with TBZ, has extended its stability. By synergic effect, this association produces an improvement of drug release leading to promote bioavailability. As they are easy to swallow and allow enhancing treatment efficiency, ODF appear as suitable delivery forms for pediatric patients
37

DISSOLUTION AND MEMBRANE MASS TRANSPORT OF SUPERSATURATING DRUG DELIVERY SYSTEMS

Siddhi-Santosh Hate (8715135) 17 April 2020 (has links)
<p>Supersaturating drug delivery systems are an attractive solubility enabling formulation strategy for poorly soluble drugs due to their potential to significantly enhance solubility and hence, bioavailability. Compendial dissolution testing is commonly used a surrogate for assessing the bioavailability of enabling formulations. However, it increasingly fails to accurately predict <i>in vivo</i> performance due its closed-compartment characteristics and the lack of absorptive sink conditions. <i>In vivo</i>, drug is continually removed due to absorption across the gastrointestinal membrane, which impacts the luminal concentration profile, which in turn affects the dissolution kinetics of any undissolved material, as well as crystallization kinetics from supersaturated solutions. Thus, it is critical to develop an improved methodology that better mimics <i>in vivo</i> conditions. An enhanced approach integrates dissolution and absorption measurements. However, currently-used two-compartment absorptive apparatuses, employing a flat-sheet membrane are limited, in particular by the small membrane surface area that restricts the mass transfer, resulting in unrealistic experimental timeframes. This greatly impacts the suitability of such systems as a formulation development tool. The goal of this research is two-fold. First, to develop and test a high surface area, flow-through, absorptive dissolution testing apparatus, designed to provide <i>in vivo</i> relevant information about formulation performance in biologically relevant time frames. Second, to use this apparatus to obtain mechanistic insight into physical phenomenon occurring during formulation dissolution. Herein, the design and construction of a coupled dissolution-absorption apparatus using a hollow fiber membrane module to simulate the absorption process is described. The hollow fiber membrane offers a large membrane surface area, improving the mass transfer rates significantly. Following the development of a robust apparatus, its application as a formulation development tool was evaluated in subsequent studies. The dissolution-absorption studies were carried out for supersaturated solutions generated via anti-solvent addition, pH-shift and by dissolution of amorphous formulations. The research demonstrates the potential of the apparatus to capture subtle differences between formulations, providing insight into the role of physical processes such as supersaturation, crystallization kinetics and liquid-liquid phase separation on the absorption kinetics. The study also explores dissolution-absorption performance of amorphous solid dispersions (ASDs) and the influence of resultant solution phase behavior on the absorption profile. Residual crystalline content in ASDs is a great concern from a physical stability and dissolution performance perspective as it can promote secondary nucleation or seed crystal growth. Therefore, the risk of drug crystallization during dissolution of ASDs containing some residual crystals was assessed using absorptive dissolution measurements and compared to outcomes observed using closed-compartment dissolution testing. Mesoporous silica-based formulations are another type of amorphous formulations that are gaining increased interest due to higher physical stability and rapid release of the amorphous drug. However, their application may be limited by incomplete drug release resulting from the adsorption tendency of the drug onto the silica surface. Thus, the performance of mesoporous silica-based formulations was also evaluated in the absorptive dissolution testing apparatus to determine the impact of physiological conditions such as gastrointestinal pH and simultaneous membrane absorption on the adsorption kinetics during formulation dissolution. Overall, the aim of this research was to demonstrate the potential of the novel <i>in vitro</i> methodology and highlight the significance of a dynamic absorptive dissolution environment to enable better assessment of complex enabling formulations. <i>In vivo</i>, there are multiple physical processes occurring in the gastrointestinal lumen and the kinetics of these processes strongly depend on the absorption kinetics and <i>vice-a-versa</i>. Thus, using this novel tool, the interplay between solution phase behavior and the likely impacts on bioavailability of supersaturating drug delivery systems can be better elucidated. This approach and apparatus is anticipated to be of great utility to the pharmaceutical industry to make informed decisions with respect to formulation optimization.</p>
38

Generation of high drug loading amorphous solid dispersions by different manufacturing processes / Génération de dispersions solides amorphes à forte charge en principe actif par différents procédés de fabrication

Lins de Azevedo Costa, Bhianca 13 December 2018 (has links)
La principale difficulté lors de l'administration orale d'un ingrédient pharmaceutique actif (API) est de garantir que la dose clinique de l’API sera dissoute dans le volume disponible de liquides gastro-intestinaux. Toutefois, environ 40% des API sur le marché et près de 90% des molécules en cours de développement sont peu solubles dans l’eau et présentent une faible absorption par voie orale, ce qui entraîne une faible biodisponibilité. Les dispersions solides amorphes (ASD) sont considérées comme l’une des stratégies plus efficaces pour résoudre des problèmes de solubilité des principes actifs peu solubles dans l’eau et, ainsi, améliorer leur biodisponibilité orale. En dépit de leur introduction il y a plus de 50 ans comme stratégie pour améliorer l’administration orale des API, la formation et la stabilité physique des ASD font toujours l'objet de recherches approfondies. En effet, plusieurs facteurs peuvent influer sur la stabilité physique des ASD pendant le stockage, parmi lesquels la température de transition vitreuse du mélange binaire API-polymère, la solubilité apparente de l'API dans le polymère, les interactions entre l'API et le polymère et le procédé de fabrication. Cette thèse consistait en deux parties qui avaient pour objectif le développement de nouvelles formulations sous forme d’ASD d'un antirétroviral, l'Efavirenz (EFV), dispersé dans un polymère amphiphile, le Soluplus, en utilisant deux procédés différents, le séchage par atomisation (SD) et l'extrusion à chaud (HME). EFV est l’API BCS de classe II de notre choix car c’est un API qui représente un défi pour les nouvelles formulations. En effet, il a besoin d’ASD plus fortement concentrées, pour lesquelles la stabilité chimique et physique pendant le stockage et la dissolution seront essentielles. Dans le but de développer de manière rationnelle les ASDs EFV- Soluplus à forte concentration, la première partie s'est concentrée sur la construction d'un diagramme de phases EFV-Soluplus en fonction de la composition et de la température. Le diagramme de phases a été construit à partir d'une étude thermique de recristallisation d'un ASD sursaturé (85 %m EFV), générée par séchage par atomisation. À notre connaissance, il s'agit de la première étude à présenter un diagramme de phase pour ce système binaire. Ce diagramme de phases est très utile et démontre que la solubilité de l'EFV dans les solutions varie de 20 %m (25 °C) à 30 %m (40 °C). Les ASD de EFV dans le Soluplus contenant plus de 30 %m d'EFV doivent être surveillées pendant le stockage dans des conditions typiques de température. Ce diagramme de phases peut être considéré comme un outil de pré-formulation pour les chercheurs qui étudient de nouvelles ASD d'EFV dans le Soluplus afin de prédire la stabilité (thermodynamique et cinétique). Les ASD préparées par différentes techniques peuvent afficher des différences dans leurs propriétés physicochimiques. La deuxième partie de cette thèse portait sur la fabrication d’ASD par des procédés HME et SD. Cette étude montre clairement que la formation d’ASD est une stratégie de formulation utile pour améliorer la solubilité dans l'eau et la vitesse de dissolution de l'EFV à partir de mélanges binaires EFV-Soluplus. Les procédés de fabrication (HME et SD) se sont révélés efficaces pour générer des ASD dans une large gamme de compositions en EFV. L'optimisation du ratio EFV-Soluplus peut être utilisée pour adapter la libération cinétique des ASD. Le choix d’une charge EFV élevée dépassant la solubilité thermodynamique de l’EFV dans le Soluplus est possible, mais il convient de prendre en compte sa stabilité cinétique dans le temps. / The main difficulty when an Active Pharmaceutical Ingredient (API) is orally administered is to guarantee that the clinical dose of the API will be dissolved in the available volume of gastrointestinal fluids. However, about 40% of APIs with market approval and nearly 90% of molecules in the discovery pipeline are poorly water-soluble and exhibits a poor oral absorption, which leads to a weak bioavailability. Amorphous solid dispersions (ASD) are considered as one of the most effective strategies to solve solubility limitations of poorly-water soluble compounds and hence, enhance their oral bioavailability. Despite their introduction as technical strategy to enhance oral APIs bioavailability more than 50 years ago, ASD formation and physical stability remains a subject of intense research. Indeed, several factors can influence the physical storage stability of ASD, among them, the glass transition temperature of the API-carrier binary mixture, the apparent solubility of the API in the carrier, interactions between API and carrier, and the manufacturing process. This thesis consisted of two parts that aim on developing new formulations of ASD of an antiretroviral API, Efavirenz (EFV), dispersed in an amphiphilic polymer, Soluplus, by using two different processes, Spray-drying (SD) and Hot-melt extrusion (HME). EFV is the class II BCS API of our choice because it is a challenging API for new formulations. It needs higher-dosed ASDs, for which chemical and physical stability during storage and dissolution will be critical. Aiming a rational development of high-loaded EFV-Soluplus ASDs, the first part focused on the construction of a temperature- composition EFV-Soluplus phase diagram. The phase-diagram was constructed from a thermal study of recrystallization of a supersaturated ASD (85 wt% in EFV), generated by spray drying. To our knowledge, this is the first study reporting a phase-diagram for this binary system. This phase-diagram is very useful and demonstrated that the EFV solubility in Soluplus ranges from 20 wt% (25 °C) to 30 wt% (40 °C). ASD of EFV in Soluplus containing more than 30 wt% of EFV should be monitored over storage under typical temperature conditions. This phase-diagram might be considered as a preformulation tool for researchers studying novel ASD of EFV in Soluplus, to predict (thermodynamic and kinetic) stability. ASD prepared by different techniques can display differences in their physicochemical properties. The second part of this thesis focused on the manufacturing of ASD by HME or SD processes. This study clearly shows that ASD is a useful formulation strategy to improve the aqueous solubility and the dissolution rate of EFV from EFV-Soluplus binary mixtures. HME and SD manufacturing processes demonstrated to be efficient to generate ASDs in a large range of compositions and loads of EFV. The optimization of EFV to Soluplus ratio can be used to tailor the release kinetics from ASD. The choice of a high EFV load exceeding the thermodynamic solid solubility in Soluplus is possible but it needs the consideration of its kinetic stability over time.

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