68 results about "Burst effect" patented technology

The present invention relates to a molecular sustained controlled release system constructed by the conjugation of molecules to be released with biodegradable polyester polymer via covalent bond and method for preparation thereof. In accordance with the present invention, the system may be formulated into microspheres, nanoparticles, or films. The molecular release rate from the above system can be regulated to be proportional to the chemical degradation rate of the biodegradable polyester polymers, resulting in near zero order kinetics profile of release without showing a burst effect, Moreover, a high loading efficiency of hydrophilic drugs can be achieved.

The invention discloses an adsorption method for preparing hydroxyapatite pesticide and slow-release fertilizer compound, which comprises the following steps: soaking a nano hydroxyapatite carrier in phosphate buffer solution, then adding a starting material into the buffer solution and continuously stirring the mixture to form compound solution, finally centrifuging the compound solution to obtain sediment, and drying the sediment to obtain the compound. By using a porous structure of the nano hydroxyapatite self to embed medicaments into an internal grid of the carrier, the burst effect of the medicaments is avoided, the medicinal effect is long, the medicament residue is greatly reduced, and the medicaments are safer. A product obtained by using the nano hydroxyapatite as a pesticide and fertilizer carrier has the advantages of reliable quality, strong stability, safe use and low cost, greatly improves the medicament loading amount and adsorption amount, is easy for continuous production, and has good application prospect.

The invention provides methods and articles for the administration of a biologically active substance (BAS). These methods and articles provide for the controlled and sustained delivery of relatively large quantities of these substances with a low burst effect. The articles made using the method of the invention have increased percentages (w/w) of macromer, increased crosslinking density, and reduced pore size in comparison to articles made using solution methods.

The invention relates to an absorbable magnesium alloy stent of anticorrosion and drug release composite coating and a preparation method thereof. The absorbable magnesium alloy stent comprises a magnesium alloy stent skeleton and composite coating, wherein the surface layer of the magnesium alloy stent skeleton is an inorganic anti-corrosion coating, the outside of the inorganic anti-corrosion coating is provided with organic sealing and drug release composite coating; and the inorganic anti-corrosion coating is dense coating with metallurgical structure composed of MgSiO3, MgO and SiO2 with zeolite structure. The inorganic anti-corrosion coating is prepared on the surface of a matrix through microarc oxidation, and the sealing and drug release composite coating composed of crosslinked gelatin/PLGA medicine-carried nanospheres blend film is prepared outside the anti-corrosion coating. The absorbable magnesium alloy stent of the invention effectively controls the corrosivity of the magnesium alloy stent, the organic coating has double functions, the use of the sealing inorganic coating increases the corrosion resistance, controls the drug to release, and reduces the burst effect of the drug to ensure that the drug is released in a certain concentration continuously and slowly. Meanwhile, each coating can be biodegraded and the degradation product is non-toxic, thus effectively improving the biocompatibility and blood compatibility of the magnesium alloy surface.

The invention relates to a preparation method of a pH-sensitive coaxial drug-loading nanometer fiber membrane. The method comprises the following steps: dissolving a high polymer material with pH-sensitivity into ethanol to obtain a transparent and clear high polymer solution serving as a shell material; and in addition, dissolving a medicine and a high polymer material into ethanol or a water solution, and mixing evenly to obtain a core liquid; and pouring the obtained spinning solution into an injection propeller, and spinning by using a coaxial electrostatic spinning method to obtain the drug-loading nanometer fiber membrane. The method is simple in process, and low in cost; a pH-sensitive material is applied to a shell layer in coaxial fibers; and the material with good drug compatibility is applied to a drug-loading core layer, so that the drug burst effect can be effectively avoided; and the prepared nanometer fiber membrane can achieve pH-response drug release, and has a relatively good application prospect in targeted drug delivery of gastrointestinal tracts.

The invention provides an oral slow/controlled-release preparation containing febuxostat and a preparation method thereof, which prepare the febuxostat into the long-acting oral slow/controlled-release preparation and can solve the problem that the incidence of an adverse reaction is increased because of the quicker dissolving-out and the burst effect of a common preparation existing in the prior art. The invention has the technical scheme that the oral slow/controlled-release preparation containing the febuxostat comprises the following components by weight percent: 5 to 60 percent of febuxostat, 10 to 50 percent of slow/controlled-release material, 20 to 80 percent of filling auxiliary material, 0.3 to 20 percent of adhesive and 0.1 to 7 percent of lubricant or glidant. Compared with a common quick-release preparation, the slow/controlled-release preparation can keep the effective and stable blood concentration for a longer time, avoids the burst effect of the quick-release preparation, lowers the incidence of the adverse reaction and enhances the application safety.

The present invention is a solid dosage form for oral administration of ibuprofen comprising a modified release formulation of ibuprofen which provides an immediate burst effect and thereafter a sustained release of sufficient ibuprofen to maintain blood levels at least 6.4 μg/ml over an extended period of at least 8 hours following administering of a single dose.

The invention relates to the technical field of pharmaceutical preparation, in particular to an asiatic acid sustained-release microsphere used for injection and a preparation method thereof. A biodegradable chitosan is taken as a carrier, an asiatic acid is taken as principal agent, and the asiatic acid sustained-release microsphere used for injection is obtained by the technology of cross-linked emulsion. Due to the obtained medicament carried microspheres, the surfaces are relatively smooth; the particle diameters range from 20mum to 110mum; and the medicament loading rate of the microspheres ranges from 4.8% to 15.6%. The asiatic acid microsphere has the characteristics that the burst effect is modest (the burst size on the first day is smaller than 15%); the release rate is stable; the sustained release time is long (4-10 weeks); and the asiatic acid microsphere is biodegradable. The implantation and the removal by operation before and after the medicament is used are avoided.

The invention discloses a dual drug-loading composite microsphere and a preparation method thereof, belonging to the technical field of biomedical materials. The composite microsphere has a microsphere-in-microsphere structure, a matrix consists of polylactic-co-glycolic acid microspheres in the interior and a chitosan shell at the outer layer, and drugs are respectively embedded in the interior microspheres and the shell, wherein the total drug-loading rate is 1 to 10 percent, the average grain diameter of the interior microspheres is 100-1000nm, and the average grain diameter of the composite microspheres is 10-100 mum. The invention also discloses the preparation method of the composite microsphere. The composite microsphere has good biocompatibility and biodegradability, and can control drug adding amount of the two times or the drug concentration or the drug species, thus reducing burst effect and alleviating the acidity caused by PLGA degradation.

The invention discloses a doxycycline-hyclate-carried GTR (Guide Tissue Regeneration)/GBR (Guide Bone Regeneration) composite membrane and a preparation method thereof and belongs to the technical field of medicines. The GTR/GBR composite membrane adopts a three-layer structure, wherein the upper surface layer, the lower surface layer and the sandwich layer are all manufactured through sequence electrospinning; the upper surface layer and the lower surface layer are prepared from a natural polymer material and a mixed solution through which the polymer material is synthesized; the sandwich layer is a membrane layer prepared from a doxycycline-hyclate-carried solution through which the polymer material is synthesized. The uniaxial sequence electrospinning method is adopted to prepare the composite membrane adopting the three-layer structure, so that the medicine entrapment efficiency of fibers is improved, the preliminary burst effect of a medicine is reduced/eliminated, and continuously slow release of the medicine is realized. The two surface layers of the three-layer medicine-carried composite membrane can not only serve as porous barriers to control the medicine release rate so as to realize continuously slow release of the medicine but also prevent direct contact between the medicine and tissues to improve the compatibility between the tissues and the membrane so as to be more conducive to tissue repair and regeneration.

A process is described for loading hydrophilic polymer particles with a water-insoluble solvent-soluble drug. The particles are preferably embolic agents. The method provides particles having little or no drug at the surface and in a surface layer, whereby the burst effect is minimised. The drug is precipitated in the core of the particle, leading to extended release. The drug is, for instance, paclitaxel, rapamycin, dexamethasone or ibuprofen.

The invention relates to a preparation method of a vesicle-loaded multivescular liposome. The preparation method comprises the steps of adopting nanoscale vesica and an osmotic pressure regulator as an inner water phase and an organic solvent of a lipid with good biocompatibility as an oil phase, dispersing the inner water phase into the oil phase to form a W/O primary emulsion; dispersing the primary emulsion into an outer water phase containing the osmotic pressure regulator and an auxiliary emulsifier to form a W/O/W compound emulsion; and transferring the compound emulsion to the same outer water phase and removing an organic solvent through rotary evaporation or nitrogen introduction to obtain a multivescular liposome suspension. According to a multivescular liposome preparation, the encapsulation efficiency of a loaded drug can be ensured, the biological activity of biomacromolecules can be improved, the immunogenicity is reduced, the burst effect is reduced and sustained slow release of the drug is ensured.

The present invention is a solid dosage form for oral administration of ibuprofen comprising a modified release formulation of ibuprofen which provides an immediate burst effect and thereafter a sustained release of sufficient ibuprofen to maintain blood levels at least 6.4 g/ml over an extended period of at least 8 hours following administration of a single dose. The dosage form releases ibuprofen at a rate sufficient to initially deliver a effective amount of ibuprofen within about 2.0 hours following administration. The dosage form then subsequently delivers the remaining amount of ibuprofen at a relatively constant rate sufficient to maintain a level of ibuprofen over a predetermined delivery period of for at least 8 hours.

A fireworks artillery shell for use as a consumer firework which may be propelled by the use of a mortar is provided which includes a casing, a lift charge, an effects charge, a timing fuse and an ignition fuse, and seals. The seals are provided within the casing above and below the effects charge to increase the burst effect of the effects charge. The lift charge is positioned within the casing and below the lower seal, and upon ignition, lifts the fireworks artillery shell into the air. The seals promote a harder break and more explosive effect from the effects charge without interfering with the lifting charge.

The invention relates to a method for dyeing an interface of a bursting body. In the method, a container filled with dye of a certain color is placed on the bottom of a blast hole to be burst; when the blast hole of a dye bag is burst, the container can be cracked under the action of the burst pressure of an explosive and release the dye, the dye can dye ores or rocks near the bottom of the blasthole, and then the dyed ores or rocks become dyeing interfaces of bursting ore loosing bodies. By using the method, a specific interface mark of a burst body can be formed, which can provide the change information of the interfaces of the burst ores and rocks of an underground mine in a closed space, can provide a new means for ore drawing control management and research in a stope caving method of the underground mine, and also provide a new evidence for bursting effect analysis.

The invention relates to an emulsion explosive and a preparation method thereof. The emulsion explosive comprises the following components in parts by weight: 70-80 parts of ammonium nitrate, 5-6 parts of sodium nitrate, 10-15 parts of water, 3-4 parts of composite wax, 0.3-0.8 part of engine oil, 1-1.7 parts of composite emulsifying agent, 0.5-1 part of polymer emulsifying agent and 1.2%-1.7% (based on total weight of the components) of glass beads, wherein the composite emulsifying agent is a mixture of Span 80 and T152 emulsifying agent in a weight ratio of 6 to 4. According to the emulsion explosive disclosed by the invention, various indexes satisfy the relevant national regulations, and the performances reach three international standards, the gap distance for sympathetic detonation reaches 5, the performance quality of the explosive is improved and the burst effect is ideal. Moreover, the high polymer emulsifying agent is added to the explosive formula, so that the storage period of the emulsifying explosive is prolonged to one year from half a year, and therefore, the storage cost of the explosive is reduced. Meanwhile, the composite wax and the engine oil are used in the formula, so that the price is low, the resources are extensive and the production cost is reduced.