Search results for "Controlled release"

Enzyme-Responsive Controlled Release Using Mesoporous Silica Supports Capped with Lactose

2009

Controlled release of drugs: Polymers and aggregate systems. Edited byM. Rosoff, VCH Verlagsgesellschaft, Weinheim, 1989, xi, 315 pp., bound, DM 132.…

1989

Photocleavable microcapsules built from photoreactive nanospheres.

2005

We show how photo-cross-linking of nanoparticles within the micrometer-sized thin oil shell of water-oil-water emulsion droplets leads to a new species of optically addressable microcontainers. The inner water droplet of these emulsions may contain drugs, dyes, or other water-soluble components, leading to filled containers. The thickness, mechanical stability, and light resistance of the container walls can be controlled in a simple way by the amount and adjustable photoreactivity of the nanoparticles. Importantly, the chemical bonds between the nanoparticles constituting the microcapsule shell can be cleaved photochemically by irradiation with UV light. This optically controlled destructi…

Designing Medical Devices Based on Silicon Polymeric Material with Controlled Release of Local Anesthetics

2012

The drug delivery systems that are the object of this article take the form of a polymer matrix made of silicone containing a drug. These devices can be used as patches for local dermal applications releasing the drug in a controlled manner. The model active agent, lidocaine hydrochloride was chosen from the range of local anesthetics. When the drug is restricted to the surface, it is released more rapidly than when it is allowed to spread evenly throughout the silicon structure. When hydrophilic polymers such as PVA and HEC are mixed in with the lidocaine hydrochloride and deposited on the surface of the polymer matrix, we observed that the burst effect was eliminated without modifying the…

Incorporation of Pt(II) complex with [amino-2(methylthio)(1,2,4)triazole-(1,5-a)pyrimidine-6-carboxylic-acid] ligand in MCM41 for controlled release

2015

Drug carriers play a critical role for the loading and the release of the drug. A promising frontier is represented by a new class of innovative medicines that represents directional transport vehicles "drug delivery" and consist of assembled structures carrier (nano)-drug. Silica-based materials, nontoxic, biocompatible, have been used as adjuvant and excipient in pharmaceutical technology. In this class of compounds, the mesoporous materials, such as MCM41, SBA-15 and hexagonal mesoporous silica, have been investigated for medication and drug delivery due to their properties. In fact, these materials show a large specific pore volume made up of regular pores having a diameter in the nanom…

Functionalization of nanoparticles in specific targeting and mechanism release

2017

The development of various nanotechnologies have provided a new field of research, which allows the manipulation of molecular components of matter and covers a vast array of nanodevices. The “smart” multifunctional nanostructures should work as customizable, targeted drug-delivery vehicles capable of carrying large doses of therapeutic agents into malignant cells. Some nanomedical approaches are based on the use of functionalized nanoparticles (NPs), not only to reduce toxicity and side effects of drugs but, also in potential the biological barriers crossing on, such as: the blood–brain barrier, different cellular compartments, including the nucleus. Currently, many materials are used for n…

Influence of low methoxyl pectin gel textures and in vitro release of rutin from calcium pectinate beads.

2013

This study described the preparation and characterization of low methoxyl pectin (LMP) gels and beads for controlled release applications. The rheological characterization of the various formulations was proposed. Then the mechanical and morphological characterizations of beads were determined. Finally, the controlled release studies taking rutin as a model drug was evaluated. The results showed that Young's modulus values of non-amidated LMP gels decrease when adding up to 15% sorbitol. Calcium pectinate beads loaded with rutin are about 600 μm, oblong shaped with dense matrix. Beads containing sodium bicarbonate showed about 80% lower rutin encapsulation efficiency by increasing the pH of…

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…

Covalently modified halloysite clay nanotubes: synthesis, properties, biological and medical applications

2017

Halloysite (HNT) is a promising natural nanosized tubular clay mineral that has many important uses in different industrial fields. It is naturally occurring, biocompatible, and available in thousands of tons at low cost. As a consequence of a hollow cavity, HNT is mainly used as nanocontainer for the controlled release of several chemicals. Chemical modification of both surfaces (inner lumen and outer surface) is a strategy to tune the nanotube's properties. Specifically, chemical modification of HNT surfaces generates a nanoarchitecture with targeted affinity through outer surface functionalization and drug transport ability from functionalization of the nanotube lumen. The primary focus …

Halloysite Nanotubes Coated by Chitosan for the Controlled Release of Khellin

2020

In this work, we have developed a novel strategy to prepare hybrid nanostructures with controlled release properties towards khellin by exploiting the electrostatic interactions between chitosan and halloysite nanotubes (HNT). Firstly, khellin was loaded into the HNT lumen by the vacuum-assisted procedure. The drug confinement within the halloysite cavity has been proved by water contact angle experiments on the HNT/khellin tablets. Therefore, the loaded nanotubes were coated with chitosan as a consequence of the attractions between the cationic biopolymer and the halloysite outer surface, which is negatively charged in a wide pH range. The effect of the ionic strength of the aqueous medium…