314 results about "Drug release rate" patented technology

Coatings and methods of forming coatings for implantable medical devices, such as stents, are described. The coatings are used for the sustained release of a therapeutic agent or drug.

A method of making a drug eluting stent comprises forming a porous stent body surface layer by ion implantation, applying a layer of ceramic particles on the porous layer and compressing the layer of ceramic particles. The layer of ceramic particles can be compressed to successively higher densities. Drugs can be loaded into the layer of ceramic materials at a relatively low density before the layer of ceramic materials is compressed to a higher density to achieve a desired low drug release rate.

Methods of modifying properties such as degradation rate and drug release rate of polymer stents with radiation are disclosed.

The invention discloses a multi-layer drug sustain-release nano fiber membrane and a preparation method thereof. The inner layer and outer layer of the multi-layer membrane are both composed of a polymer A nano fiber with a good biological compatibility, and the middle layer is a drug-carrying nano fiber which is prepared by blending curcumin (CM) and a polymer B with a good biological compatibility. The preparation method comprises the following steps: dissolving the polymer A into a solvent, subjecting the polymer A to an electrostatic spinning process so as to prepare the inner layer, then subjecting a mixed solution of the polymer B and CM to an electrostatic spinning process, continuously depositing the mixed solution on the inner layer so as to obtain the middle layer, finally subjecting the polymer A to an electrostatic spinning process for a second time, and continuously depositing the polymer A on the middle layer so as to obtain the outer layer. The membrane preparation method is simple, can effectively relieve the burst release phenomenon in the early release stage, and can control the drug release by changing the thickness of the polymer A. Taking polymer A-polylactic acid (PLA), and polymer B-cellulose acetate (CA) as an example, the in vitro drug release test results have shown that the drug release rate of the multi-layer drug-carrying membrane is both less than that of a single layer drug loaded membrane no matter after 1 hour or after 240 hours.

A coated implantable medical device and a method of coating an implantable medical device is disclosed, the method includes applying a composition onto the device and drying the composition at elevated temperature in an environment having increased relative humidity. A pre-screening method for a manufacturing lot of coated stents to determine the number of drug coating layers for a desired drug release rate is disclosed. The method including coating and testing small groups of stents, and applying the results of the tests to determine the number of drug coating layers to apply to the manufacturing lot of stents.

Disclosed is a polymer conjugate of folic acid or a folic acid derivative, wherein an amide bond is not used. The compound has chemical stability and adequate drug release rate in the living organism. Specifically disclosed is a polymer conjugate of folic acid or a folic acid derivative, wherein a substituent represented by formula (I) is bonded to a carboxy group of a block copolymer which is composed of a polyethylene glycol and a polymer having a carboxy group in a side chain, or a pharmacologically acceptable salt thereof.

[In the formula, A represents a monocyclic or fused aromatic group; G represents an optionally substituted (C1-C6) alkylene group; Y represents a hydrogen atom or a substituent; and E represents a residue of folic acid or a folic acid derivative.]

The invention relates to a method for preparing a shell-sheddable polymer micelle drug carrier. The drug carrier is a disulfide bond bridging amphiphilic copolymer, and the disulfide bond can be rapidly cracked under reduction environment in cells to realize the intelligent drug release function through the shell shedding, so the amphiphilic copolymer can rapidly self-assemble into micelle nanoparticles and loading drugs in water. Compared with drug carriers prepared with the prior art, the shell-sheddable polymer micelle drug carrier allows the drug release rate under high concentration glutathione environment to be 3-5 times faster than the drug release rate under glutathione-free environment, can be used to control the release of drugs in tumor cells, and has obvious inhibition on the tumor cells, and the drug carrying micelle particles can stably clad anticancer drugs, so a novel high efficiency drug carrier system is provided for the tumor treatment.

A paliperidone double-layered osmotic pump controlled release tablet and the preparation method thereof are disclosed. The double-layered osmotic pump controlled release tablet comprises a rigid membrane, a push layer, a drug layer, an isolation layer and an aesthetic coating, wherein the rigid membrane contains a semi-permeable polymer, a porogen and/or a plasticizer and has one or more drug release orifices on one end, the push layer comprises an expanding material, an osmotic agent, a binder, a colorant and a lubricant, the drug layer contains a pharmaceutically active ingredient, a hydrophilic polymer, an osmotic agent, a colorant, a lubricant and an antistatic agent, the isolation layer is located between the inner surface of the rigid membrane and the push layer, and contains a hydrophilic polymer. The paliperidone double-layered osmotic pump controlled release tablet shows an increasing drug release rate at early stage and keeps a constant drug release rate at later stage.

The invention provides a preparation method and application of a Fe3O4@SiO2 yolk-eggshell-structured hollow composite microsphere. The preparation method comprises the following steps: preparing Fe2O3 nanoparticles by using a solvothermal method; under the condition that no surfactant is added and TEOS is used as a silicon source, preparing a Fe3O4@SiO2 composite microsphere with controllable morphology under mild conditions by using a combination of a template method and a hydrothermal method; corroding the Fe3O4@SiO2 composite microsphere with hydrochloric acid with a certain concentration so as to obtain a Fe3O4@SiO2 yolk-eggshell-structured hollow composite microsphere; and carrying out reduction so as to prepare the Fe3O4@SiO2 yolk-eggshell-structured hollow composite microsphere with superparamagnetism. The prepared Fe3O4@SiO2 yolk-eggshell-structured hollow composite microsphere has a specific surface area of 173 m<2>/g and drug loading capacity of 139 mg/g; and with doxorubicin hydrochloride as a drug model, the Fe3O4@SiO2 yolk-eggshell-structured hollow composite microsphere has a drug release rate of as high as 68.4% within 72 h in a PBS buffer solution with a pH value of 7.4, so the composite microsphere presents good slow drug release performance.

A coating device for coating a medical device with a drug-eluting material uses an in-process drying station between coats to improve a drug release profile. The drying station includes a dryer having a telescoping plenum which provides a drying chamber for the stent or scaffold to reside while a heated gas is passed over the stent/scaffold. The drying chamber improves efficiency in drying, predictability or drug release rate, uniformity of coating material properties lengthwise over the stent/scaffold and provides a platform that can effectively support stents that are over 40 mm in length.

A method for preparing hydro/organo gelators from disaccharide sugars by biocatalysis and their use in enzyme-triggered drug delivery. Controlled delivery of an anti-inflammatory, chemopreventive drug is achieved by an enzyme-triggered drug release mechanism via degradation of encapsulated hydrogels. The hydro- and organo-gelators are synthesized in high yields from renewable resources by using a regioselective enzyme catalysis and a known chemopreventive and anti-inflammatory drug, curcumin, is encapsulated in the gel matrix and released by enzyme triggered delivery. The release of the drug occurs at the physiological temperature and control of the drug release rate is achieved by manipulating the enzyme concentration and temperature. The by-products formed after the gel degradation clearly demonstrated the site specificity of degradation of the gelator by enzyme catalysis. The present invention has applications in developing cost effective, controlled drug delivery vehicles from renewable resources, with a potential impact on pharmaceutical research and molecular design and delivery strategies.

A method of injecting a mixture into an eye includes: providing the mixture in a dispensing chamber with an air gap located between the mixture and an interior surface of a dispensing chamber housing, when the mixture and dispensing chamber housing are near room temperature; bringing the dispensing chamber housing and mixture to a temperature range, other than near room temperature, at which the mixture expands and is in a more liquid state; maintaining air in a needle after the mixture expands and prior to an injection; selecting a drug release rate; and injecting the mixture so as to form a shape with a surface area that results in the selected drug release rate.