Developments in high throughput screening and combinatorial chemistry have contributed to the unprecedented success of the pharmaceutical industry over the last twenty years, leading to a multitude of blockbuster compounds that revolutionized treatment for a variety of clinical indications. This success, particularly in drug discovery, has been tempered by an increased number of moieties exhibiting delivery limitations due to molecular structure. One of the most pressing areas of pharmaceutical research today is addressing the reduced aqueous solubility of developmental chemical entities in pharmaceutical pipelines, which has been estimated to affect up to 90% of such compounds. Current technologies have focused on maximizing dissolution rates or equilibrium solubilities of such compounds using platforms such as microemulsions, polymorph engineering, particle size reduction, and complexation. While these technologies have been shown to improve oral bioavailability for a number of compositions, further improvement can be achieved by developing new production and formulation technologies for amorphous systems. Within the frame work of this dissertation, two unique technologies for bioavailability enhancement were investigated; formulation with concentration enhancing polymers to provide extended durations of supersaturation and the development of a novel fusion based solid dispersion production process based on thermo-kinetic mixing, termed KinetiSol® Dispersing, for the production of amorphous solid dispersions. Studies of solid dispersions containing concentration enhancing polymers prepared by ultra rapid freezing showed the ability of these formulations to provide improved oral bioavailability of itraconazole when compared to the currently marketed product, which is a conventional hydrophilic solid dispersion. KinetiSol® Dispersing was also extensively studied within this work and shown to be a viable platform for the production of hydrophilic solid dispersions, plasticizer free solid dispersions and solid dispersions containing heat sensitive active ingredients. In a culminating study, KinetiSol® Dispersing was utilized for the production of amorphous solid dispersions containing concentration enhancing polymers for improved oral bioavailability of itraconazole. Ultimately, this body of work demonstrated that concentration enhancing polymers could provide improved oral bioavailability for poorly water soluble compounds, while KinetiSol® Dispersing could be used for the production of such compositions, thereby presenting novel technologies for addressing future development of poorly water soluble active ingredients. / text

Dans le cadre du concept de stockage de déchets radioactifs à vie longue en couche géologique profonde développé par l'Andra, l’IRSN mène une étude in situ sur la Station Expérimentale de Tournemire, en collaboration avec EDF afin de déterminer les interactions acier/argilite dans un contexte naturel. Au terme de 10 ans d’interaction, deux forages ont été sur-carottés afin de caractériser les transformations de l’argilite de Tournemire au contact d’aciers carbone et inoxydables et de comparer les phénomènes réactifs mis en évidence et ceux induits par des simulations numériques par des codes de calcul géochimique et couplant chimie-transport.Les échantillons argilite/acier carbone montrent une importante corrosion du disque d’acier. Le fer libéré sous la forme d’auréoles et dans les fissures de la roche perturbe l’argilite au contact entraînant des modifications minéralogiques et structurales. La précipitation d’oxydes de fer ainsi qu’une dissolution de la calcite et des feuillets smectitiques des interstratifiés I/S sont identifiés. Une zonation métal/métal corrodé/argilite perturbée/argilite saine est mise en évidence et des variations de porosité sont observées marquant les interfaces entre deux zones. Les simulations géochimiques montrent que l’essentiel des modifications est rapidement initié lors de la mise en place du système et que l’oxygène piégé à la fermeture du système est consommé par la corrosion des aciers mais surtout qu’il diffuse dans le matériau encaissant par gradient de concentration.Les échantillons argilite/acier inoxydable présentent une très faible corrosion par piqûration de l’acier. La minéralogie de l’argilite ne semble pas perturbée au cont / Within the framework of a long lived radioactive waste storage concept in deep geological layer developed by Andra, IRSN leads an in situ study on the Experimental Station of Tournemire, in association with EDF to determine the interactions steel/argillite in a natural context. After 10 years of interaction, two drillings overcoring performed to characterize the processings of the Tournemire argillite in contact with carbon and stainless steels and to compare reactive phenomena highlighted and those induced by simulations tools combining chemistry and transport.Argillite/carbon steel samples show a significant corrosion of steel disk. Iron released, in the form of rings and cracks in the rock, disrupts the argillite in contact resulting in mineralogical and structural changes. Iron oxides precipitation and a calcite and smectitic leaf of mixed-layers I/S dissolution are identified. A succession of areas: metal/metal corroded/argillite disturbed/argillite is highlighted and porosity variations are observed on the interfaces between two areas. Geochemical simulations show that major changes are initiated speedly during establishment of the system and the oxygen trapped in the closed system is consumed by the corrosion of steel but mostly it diffuses into the surrounding material through concentration gradient.Argillite/stainless steel samples have a very low pitting corrosion of steel disk. This does not seem to affect the mineralogy of the argillite in contact.