Synthesis and characterization of dextran esters as coating or matrix systems for oral delivery of drugs targeted to the colon

Different dextran esters with various degrees of substitution (1, 2 and 3) were synthesized by esterification reaction, with three acid anhydrides: acetic anhydride, propionic anhydride, and butyric anhydride, separately. These modified polysaccharides were characterized by FT-IR, 1H NMR and 13C NMR spectroscopies. Enzymatic degradation of biopolymers by dextranase was also studied. The polymers showing the best degradation profiles were chosen to design blended free films in combination with a polymethacrylate (Eudragit® RS 30D) as a sustained release system for targeting to the colon. These free films were evaluated by permeability of theophylline used as tracer in different in vitro media of the gastro intestinal tract, in presence or in absence of dextranase. From these studies, it was concluded that dextran esters having the lower degree of substitution and constituted of short carbohydrate chains showed the best and significant enzymatic degradation and could be used as a promising carrier for specific colon drug delivery system.Keywords: Colon-Specific Drug Delivery; Polysaccharides; Dextran; Dextranase; Dextran esters; Enzymatic Degradation; Eudragit® RS 30D; Sid-by-side diffusion cel

Prospects of therapeutic applications of nanotechnologies in veterinary medicine

The advent of the nanotechnologies opened vast prospects for the development of new products and applications in many industrial fields and consumption. Following the example of other fields, the nanotechnologies promised to revolutionize human medicine, veterinary medicine, the whole food chain – production, transformation, storage and clarification of applications thanks to new materials and products. However, whereas the possibilities of application of the nanotechnologies are considerable, its current use in the fields of human and animal health, food and agriculture is relatively restricted because of the emergent character of this science. Like any other field, food industry evolves with the liking of the innovations, competition and profitability. It is thus always in search of new technologies to improve the administration, the taste, the flavour and the texture of its products, to prolong the shelf life of it and to improve the security and the traceability of it. This is why the emergence of the nanotechnology gave rise to the hope that it could satisfy several of these industrial needs. The main advantages of the nanotechnologies compared to other technologies follow from the features improved or innovative of materials and substances on a nanometric scale (indicated collectively by the “nanomaterial” term) which also have a much higher surface/mass rate compared to their equivalents in bulk. The very small size of nanomaterials allows the dispersion of insoluble substances in water (like the active ingredients, the dyes, the perfumes and the preservatives) in pharmaceutical products and food without it being necessary to add additional lipids or surfactants. The reduction on a nanometric scale of the bioactive substances would improve also the acceptance, the absorption and the bioavailability in the organization compared to the substances in the bulkL’avènement des nanotechnologies a ouvert de vastes perspectives pour le développement de nouveaux produits et applications dans de nombreux secteurs industriels et de la consommation. À l’instar d’autres secteurs, les nanotechnologies ont permis de révolutionner la médecine humaine, vétérinaire, la chaîne alimentaire tout entière – production, transformation, entreposage grâce à la mise au point de nouveaux matériaux et produits. Pourtant, alors que les possibilités d’application des nanotechnologies sont énormes, leur utilisation actuelle dans les secteurs de la santé humaine et animale, de l’alimentation et de l’agriculture est relativement restreinte en raison du caractère émergent de cette science. Comme tout autre secteur, l’industrie alimentaire évolue au gré des innovations, de la concurrence et de la rentabilité. Elle est donc toujours à la recherche de nouvelles technologies pour améliorer l’administration, le goût, la saveur et la texture de ses produits, en prolonger la durée de conservation et en perfectionner la sécurité et la traçabilité. C’est pourquoi l’arrivée des nanotechnologies a fait naître l’espoir qu’elles pourraient satisfaire bon nombre de ces besoins industriels. Les principaux avantages des nanotechnologies par rapport aux autres technologies découlent des fonctionnalités améliorées ou novatrices de matériaux et de substances à l’échelle nanométrique (désignés collectivement par le terme «nanomatériaux») qui disposent également d’un taux beaucoup plus élevé surface/masse par rapport à leurs équivalents en vrac. La très petite taille des nanomatériaux permet la dispersion de substances insolubles dans l’eau (comme les principes actifs, les colorants, les parfums et les agents de conservation) dans des produits pharmaceutiques et alimentaires sans qu’il soit nécessaire d’ajouter des graisses ou des agents tensioactifs supplémentaires. La réduction à l’échelle nanométrique des substances bioactives améliorerait aussi l’acceptation, l’absorption et la biodisponibilité dans l’organisme par rapport aux substances en vra

Analytic/Synthetic and Semantics

Proceedings of the 2nd Annual Meeting of the Berkeley Linguistics Society (1976), pp. 375-38

Linguistics

Contains reports on four research projects.U. S. Air Force (Electronics Systems Division) under Contract AF 19(628)-2487Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E)National Science Foundation (Grant GK-835)National Institutes of Health (Grant 2 PO1 MH-04737-06)National Aeronautics and Space Administration (Grant NsG-496

Linguistics

Contains reports on four research projects.National Institutes of Health (Grant MH-13390-01U. S. Air Force (Electronic Systems Division) under Contract AF 19(628)-248

Burkholderia fungorum Septicemia

We report the first case of community-acquired bacteremia with Burkholderia fungorum, a newly described member of the Burkholderia cepacia complex. A 9-year-old girl sought treatment with septic arthritis in her right knee and ankle with soft tissue involvement. Commercial identification systems did not identify the causative microorganism

Burkholderia fungorum Septicemia

We report the first case of community-acquired bacteremia with Burkholderia fungorum, a newly described member of the Burkholderia cepacia complex. A 9-year-old girl sought treatment with septic arthritis in her right knee and ankle with soft tissue involvement. Commercial identification systems did not identify the causative microorganism