Search results for "drug release"

pH-sensitive hydrogel based on a novel photocross-linkable copolymer.

2004

A pH sensitive hydrogel has been prepared by a UV irradiation technique. Starting polymer was the PHM (poly hydroxyethylaspartamide methacrylated) obtained from polyaspartamide (PHEA) partially derivatized with methacrylic anhydride (MA). This new copolymer has been further derivatized with succinic anhydride (SA) to obtain PHM-SA that has been cross-linked by UV irradiation to form a pH sensitive hydrogel. The network, recovered after washing as a powder, has been been characterized by FT-IR spectrophotometry and particle size distribution analysis. Moreover, to have information about water affinity of the prepared sample, swelling measurements have been carried out in aqueous media mimick…

Core‐shell nanoparticles with hyperbranched poly(arylene‐oxindole) interiors

2009

Opracowano synteze wysoce rozgalezionego poli(aryleno-oksyndolu) na drodze reakcji polimeryzacji pochodnej 5-bromoizatyny, a nastepnie modyfikacji terminalnych jednostek izatynowych. Tak przygotowany polimerowy rdzen, charakteryzujący sie stopniem rozgalezienia 100 %, byl substratem do rodnikowej polimeryzacji z przeniesieniem atomu (z ang. ATRP) w reakcji z akrylanem tert-butylu. Otrzymane kopolimery zawierające hydrofobowy rdzen i alkilowe lancuchy zakonczone wolnymi grupami karboksylowymi tworzą sferyczne nanocząstki. Przedstawiono wstepne wyniki badan dotyczących ich wlaściwości fizykochemicznych oraz potencjalnych zastosowan.

Sustained release of silibinin to the posterior segment of the eye by mucoadhesive NLC

2015

Mesoporous silica microparticles gated with a bulky azo derivative for the controlled release of dyes/drugs in colon.

2018

[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 w…

Drug release from α,β-poly(N-2-hydroxyethyl)-DL-aspartamide based microparticles

2004

Spherical pH-sensitive microparticles have been prepared by reverse phase suspension polymerization technique. Starting polymer has been alpha,beta-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) partially derivatized with glycidylmethacrylate (GMA). PHEAGMA copolymer (PHG) has been crosslinked in the presence of acrylic acid (AA) or methacrylic acid (MA) at various concentration. The obtained microparticles have been characterized by FT-IR spectrophotometry, particle size distribution analysis and scanning electron microscopy. In order to have information about water affinity of the prepared samples, swelling measurements have been carried out in aqueous media which simulate some biological f…

An Overview of Functionalized Graphene Nanomaterials for Advanced Applications

2021

Interest in the development of graphene-based materials for advanced applications is growing, because of the unique features of such nanomaterials and, above all, of their outstanding versatility, which enables several functionalization pathways that lead to materials with extremely tunable properties and architectures. This review is focused on the careful examination of relationships between synthetic approaches currently used to derivatize graphene, main properties achieved, and target applications proposed. Use of functionalized graphene nanomaterials in six engineering areas (materials with enhanced mechanical and thermal performance, energy, sensors, biomedical, water treatment, and c…

INJECTABLE HYDROGEL BASED ON A NOVEL AMPHIPHILIC HYALURONIC ACID DERIVATIVE FOR CONTROLLED DRUG RELEASE

2015

A chitosan/silica hybrid 3D scaffold for simultaneous entrapment of two different hydrophilic substances

2022

We report the preparation of a hybrid chitosan/silica three-dimensional (3D) scaffold loaded simultaneously with two model hydrophilic substances, ibuprofen sodium salt and erioglaucine disodium salt. The first substance is entrapped in situ during the preparation of chitosan submillimetric beads by ionotropic gelation with sodium triphosphate, while the latter is post-loaded during the scaffold formation. Controlled release experiments carried out under neutral conditions demonstrate that the presence of nanostructured silica within the polymer matrix retards the release of both hydrophilic substances and increases the structure stability of the scaffold. Release profiles can be fitted to …

INULIN-BASED HYDROGELS: RHEOLOGICAL EVALUATION AND IN VITRO DRUG RELEASE STUDIES

2012

Assessment of the Inter-Batch Variability of Microstructure Parameters in Topical Semisolids and Impact on the Demonstration of Equivalence

2019

Demonstration of similar microstructure is essential for demonstrating the equivalence of generic topical products since the microstructure of semisolids may affect the drug release. The objective of this study was to compare the microstructure-defining physical parameters of different batches of a reference ointment containing calcipotriol and betamethasone (Daivobet 50 &micro