Materials for Pharmaceutical Dosage Forms: Molecular Pharmaceutics and Controlled Release Drug Delivery Aspects

Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles) over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development

VEDA-2, un systeme de synthese de programmes dirigee par les donnees

SIGLECNRS T 58641 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Simulation of titration experiments

Nowadays computer simulation is used in various fields, particularly in laboratories where it is used for the exploration data which are sometimes experimentally inaccessible. In less developed countries where there is a need for up to date laboratories for the realization of practical lessons in chemistry, especially in secondary schools and some higher institutions of learning, it may permit learners to carryout experiments such as titrations without the use of laboratory materials and equipments. Computer simulations may also permit teachers to better explain the realities of practical lessons, given that computers have now become very accessible and less expensive compared to the acquisition of laboratory materials and equipments. This work is aimed at coming out with a virtual laboratory that shall permit the simulation of an acid-base titration and an oxidation-reduction titration with the use of synthetic images. To this effect, an appropriate numerical method was used to obtain appropriate organigram, which were further transcribed into source codes with the help of a programming language so as to come out with the software

Effects of adding Bauxite and Oyster shell on the properties of metakaolin-based geopolymer cements

This work has investigated the possibility of use bauxite and oyster shell as mineral admixtures,to enhance the properties of metakaolin-based geopolymer cements. Raw materials(metakaolin, bauxite and oyster shell) were characterized in the first time by determination of their chemical and mineralogical compositions, particles size distribution, specific surface area, thermal analysis and then in the second time use to synthesized geopolymers. Different methods of analysis such as Fourier Transform Infrared spectroscopy(FTIR), X-Ray Diffractometry (XRD), and Scanning Electron Microscopy (SEM) were used to assess the variation of setting time, linear shrinkage and 28 days compressive strength of geopolymer pastes. The results of these analysis has showed that bauxite and oyster shells are source of Al2O3 and CaO respectively, and also contain crystalline phases. The geopolymers obtained by mixing metakaolin and bauxite have their setting time between 235 and 420min and their compressive strength between 40 and 57MPa ; for those obtained by mixing metakaolin and oyster shell the setting time is between 330 and 485min and compressive strength between 40 and 58MPa . The addition of a moderate amount (20% by mass) of bauxite or oyster shell led to improve the compressive strength of a metakaolin-based geopolymer of 43% (metakaolin-bauxite-based geopolymers) and 45% (metakaolin-oyster shell-based geopolymers) and decrease the linear shrinkage. More than 20% mineral additive has a deleterious effect on compressive strength and increase the setting time. Keywords: Metakaolin ; Bauxite ; Oyster shell ; synthesis ; Optimization; Geopolymer cements

Évaluation biopharmaceutique et pharmacocinétique, et modulation du passage transméningé de principes actifs après administration épidurale chez la brebis

La thèse porte sur l'administration d'anesthésiques locaux (ropivacaïne et bupivacaïne) et d'un antidépresseur de plus en plus utilisé pour son effet analgésique (amitriptyline). Les objectifs de la thèse étaient l'évaluation pharmacocinétique et biopharmaceutique de ces principes actifs après administration intraveineuse, intrathécale et épidurale, ainsi que l'amélioration de leur passage transméningé. Différents moyens ont été étudiés afin d'améliorer le passage transméningé, mettant en jeu une modulation pharmacologique par co-administration épidurale avec un agent vasoconstricteur (adrénaline) ou un agent promoteur d'absorption (caprate de sodium). Une modulation pharmacocinétique a consisté à fabriquer et évaluer des microsphères d'anesthésique local après administration épidurale. La biodisponibilité intrathécale après administration épidurale est faible (11.1% pour la ropivacaïne et 1.8 pour l'amitrityline). L'utilisation d'un vasoconstricteur augmente les concentrations intrathécales des anesthésiques locaux. L'influence du promoteur d'absorption sur les concentrations intrathécales est faible. Par rapport à d'autres techniques d'administration épidurale une augmentation de l'AUC intrathécale a été observée après l'administration des microsphères de ripovacaïne. La co-administration épidurale de vasoconstricteur et l'administration sous forme microparticulaire semblent être les techniques les plus intéressantes en clinique.The aim of this thesis consisted in a biopharmaceutical and pharmacokinetic evaluation of local anesthetic drugs, i.e. ropivacaine and bupivacaine, as well as antidepressant drug amitriptyline following intraveinous, epidural and intrathecal administration. This work also consisted in trying to enhance their transmeningeal uptake. Diferent ways of enhancement have been studied, such as drug pharmacological modulation by co-administration with a vasoconstrictor (epinephrine) or with an absorption enhancer (sodium caprate). A modulation of drug dosage form was also performed using local anesthetic-loaded microspheres after epidural administration. Intrathecal bioavailability after epidural administration is low (11.1% and 1.8% for ropivacaine and amitriptyline, respectively). After co-administration with the vasoconstrictor, intrathecal concentrations of local anesthetics were higher. The influence of the absorption enhancer on tne intrathecal concentrations of ropivacaine was low. Compared to other epidural administration practices, such as sequential boluses or bolus followed by infusion, intrathecal ropivacaine AUC was the highest when the drug was administrated in microspheres. Vasoconstrictor epidural co-administration and drug delivery as controlled release systems seem interesting for clinical practice.RENNES1-BU Santé (352382103) / SudocSudocFranceF

Les magasins à prix uniques, leur fonction dans le commerce de détail / Université de Bordeaux, Faculté de droitthèse pour le doctorat / soutenue... par Marguerite Enselme,...

Contient une table des matièresAvec mode text