Suchergebnisse

A series of new zinc compounds has been prepared easily under mild synthetic conditions with the drug ibuprofen incorporated as a ligand to form different coordination polymers. The host materials have a high drug content and exhibit high stability, low cytotoxicity, good biodegradability and high biocompatibility. The ion exchange mechanism involved in the ibuprofen release process and the pH-controlled drug release have been studied. ; Ministerio de Educación y Ciencia (Spain) | Ref. CTQ2010-19386/BQU ; European Union (ERF) | Ref. CTQ2010-19386/BQU ; Xunta de Galicia | Ref. 10TMT314002PR

A series of new zinc compounds has been prepared easily under mild synthetic conditions with the drug ibuprofen incorporated as a ligand to form different coordination polymers. The host materials have a high drug content and exhibit high stability, low cytotoxicity, good biodegradability and high biocompatibility. The ion exchange mechanism involved in the ibuprofen release process and the pH-controlled drug release have been studied. ; Ministerio de Educación y Ciencia (Spain) | Ref. CTQ2010-19386/BQU ; European Union (ERF) | Ref. CTQ2010-19386/BQU ; Xunta de Galicia | Ref. 10TMT314002PR

Biopolymer materials based on natural collagen (gelatin and hydrolyzed collagen) are widely used in the food, pharmaceutical and cosmetic industries due to their low toxicity, high biocompatibility, low antigenicity, and unique mechanical and technological properties. Hydrolyzed collagen, unlike gelatin, is formed by peptides with a lower molecular weight. It has higher bioavailability and biodegradability compared to gelatin. In this work, using low-temperature technologies, biopolymer matrices based on hydrolyzed collagen containing the antibacterial drug dioxidine were obtained. It has been shown that by varying such synthesis parameters such as the concentration of hydrolyzed collagen in the precursor solution (from 1 to 10%), matrix cross-linking time (0.1-24 hours), cryoforming temperature (-30 and -196 °C) it is possible to change the morphology and structure matrix, its degradation time and drug release time. The composition and structure of dioxidine/hydrolyzed collagen systems were characterized by SEM, IR and UV spectroscopy. The antibacterial activity of the resulting dioxidine/hydrolyzed collagen systems against E. coli and S. aureus was characterized by the disk diffusion method.

[EN] Mesoporous silica microparticles were prepared, loaded with the dye safranin O (M-Saf) or with the drug budesonide (M-Bud) and capped by the grafting of a bulky azo derivative. Cargo release from M-Saf at different pH values (mimicking those found in the gastrointestinal tract) in the absence or presence of sodium dithionite (a reducing agent mimicking azoreductase enzyme present in the colon) was tested. Negligible safranin O release was observed at pH 6.8 and 4.5, whereas a moderate delivery at pH 1.2 was noted and attributed to the hydrolysis of the urea bond that linked the azo derivative onto the external surface of the inorganic scaffold. Moreover, a marked release was observed when sodium dithionite was present and was ascribed to the rupture of the azo bond in the molecular gate. Budesonide release from M-Bud in the presence of sodium dithionite was also assessed by ultraviolet-visible spectroscopy and high performance liquid chromatography measurements. In addition, preliminary in vivo experiments with M-Saf carried out in mice indicated that the chemical integrity of the microparticles remained unaltered in the stomach and the small intestine, and safranin O seemed to be released in the colon. ; We thank the Spanish Government (projects MAT2015-64139-C4-4-R, MAT2015-64139-C4-2-R and MAT2015-64139-C4-1-R) and Generalitat Valenciana (project PROMETEOII/2014/047 and project AICO/2017/093) for financial support. ; Ferri, D.; Gaviña, P.; Parra Álvarez, M.; Costero, AM.; El Haskouri, J.; Amorós Del Toro, P.; Merino Sanjuán, V. (2018). Mesoporous silica microparticles gated with a bulky azo derivative for the controlled release of dyes/ drugs in colon. Royal Society Open Science. 5(8). https://doi.org/10.1098/rsos.180873 ; S ; 5 ; 8 ; Xu, X.-M., & Zhang, H.-J. (2016). miRNAs as new molecular insights into inflammatory bowel disease: Crucial regulators in autoimmunity and inflammation. World Journal of Gastroenterology, 22(7), 2206-2218. doi:10.3748/wjg.v22.i7.2206 ; DeFilippis, E. M., Longman, R., ...

Effervescent floating gastro-retentive matrix tablets present novel and promising approach towards targeted and controlled drug delivery in the stomach and in the upper part of the small intestine. This kind of dosage form could be obtained by combining in a suitable ratio effervescent compounds and hydrophilic/hydrophobic polymer/s. The aim of our investigation was to develop controlled release effervescent matrix tablet which will float over the gastric media for longer than 8 hours and will release the active compound in a continuous manner over 8 hours period. We used ranitidine HCl as a model drug which has narrow absorption window in the upper small intestine, and is a good candidate for this type of dosage forms. We employed sodium bicarbonate and citric acid as effervescent compounds and two different types of hydroxypropyl methylcellulose (HPMC K4M and HPMC K15M) as a controlled release hydrophilic polymer. Three batches of tablets were produced (one containing HPMC K4M, other containing HPMC K15M, and the third containing 1:1 mixture of these two polymers) and every batch was compressed with two different forces 5.5 kN and 4.7 kN, so completely six probes of tablets were made. All six probes complied the pharmacopoeial requirements concerning mass uniformity, content, friability and hardness. All six probes tended to float fast to the surface of the medium and tend to hydrate and swell fast enough which actions provided controlled release of the compound over period of 8 hours. No significant differences in the dissolution profiles of all six probes were noticed during the investigation.