Tesis doctoral de Antonia María Cano Sarabia
Nanotechnology is believed by many to be one of the most important scientific topics of the next decade with a huge impact on biology, pharmacology and medicine. In particular, medicine with its reliance on safe, potent, user-friendly, and target-specific therapies for important diseases such as cancer, infections or autoimmune disorders will profit from nanometer-sized devices for diagnostic and therapeutic applications. specifically, vesicles, injectable nanometer-sized particles and micelles made of advanced materials are currently under investigation for targeted delivery of toxic or water-insoluble drugs or contract agents in biological systems. Necessary key elements for a secure and directed transport of such nanocarriers in the bloodstream are high chemical and mechanical stability, good biocompatibility and biodegradability, specific targeting and clearance properties, and most of all defined functionality. therefore, the development of reproducible, efficient, environmentally friendly and easy to scale-up methodologies for the production of nanoparticulate molecular materials with controlled size and supramolecular organization is of great industrial interest, since their pharmacological features are related to their nanostructure. conventional solvent-based methodologies have many problems associated to process scaling up, process-steps, reproducibility, processing times, consumption of energy, and limited control of particle characteristics over the final particulate material. Such drawbacks are originated because these solvent-based processes are driven by temperature and/or composition changes (temperature decrease, solvent evaporation, addition of salts, etc.), Which are always slowly and non-homogeneously transmitted in liquid media. processes based on compressed fluids (cfs) have gained increasing attention as alternative solvent media because they overcome some of the limitations related to the traditional methods, offering alternative advantages of the final product. Thus, the solvation power of cfs in their liquid or supercritical state can be tuned by pressure changes, which propagate much more quickly and uniformly than temperature and solvent composition changes. Therefore, cfs allow a much greater control and tuning of the structural characteristics of the final material (size, size distribution, porosity, polymorphic nature, morphology, etc.) Than with conventional organic solvents. Indeed, processing with cfs often leads to materials with unique physicochemical characteristics, unattainable by conventional processing methodologies. therefore, the aim of this doctoral thesis is the development of new methodologies using supercritical fluids as solvent, for the preparation of uniform nanoparticulate molecular materials. the first part deals with the development of the delos-susp process for the preparation of micro- and nanoparticulate dispersed systems. Delos-susp process has shown to be efficient for the preparation of microscopic suspensions of different actives, such as cholesterol, solvent blue 35 and ibuprofen, and small unilamellar vesicles (suvs) with nanoscopic size, uniform shape and stability, unachievable by conventional procedures. The influence of the delos-susp operational parameters on the physicochemical characteristics of the obtained dispersed systems has been also deeply studied. the second part of this thesis is focused on the preparation of stable microemulsions using co2-expanded solvents and their use for the realization of confined precipitations. On the basis of this concept, a new method has been developed for the straightforward preparation of submicro- and nanoparticulate materials. This new process named piwasp (pressure induced water anti-solvent precipitation) has been used for the preparation of uniform spherical nanosized ibuprofen particles with a high crystalline grade unachievable nowadays by conventional crystallization methods using liquid solutions.
Datos académicos de la tesis doctoral «Preparación de materiales moleculares nanoparticulados y dispersos -vesículas y microemulsiones- empleando fluidos comprimidos«
- Título de la tesis: Preparación de materiales moleculares nanoparticulados y dispersos -vesículas y microemulsiones- empleando fluidos comprimidos
- Autor: Antonia María Cano Sarabia
- Universidad: Autónoma de barcelona
- Fecha de lectura de la tesis: 28/09/2009
Dirección y tribunal
- Director de la tesis
- Leonor Ventosa Rull
- Tribunal
- Presidente del tribunal: cristina Palet ballús
- angelina Angelova (vocal)
- (vocal)
- (vocal)