33results about How to "Avoid degradation reactions" patented technology

The invention relates to a medicine solid compound preparation which contains a medicine inner core prepared of one or more active medicines, and a medicine cover prepared by one or more active medicines, wherein the medicine cover is covered on the medicine inner core. The medicines reacted mutually in the compound preparation are separated and are positioned in different layers in the preparation so as to avoid the interaction. The invention also discloses a preparation method of the medicine solid compound preparation.

The invention relates to a methylergometrine maleate injection and a preparation method thereof and belongs to the technical field of pharmaceutical preparations. The methylergometrine maleate injection comprises isoosmotic adjusting agent, buffer agent, antioxygen, metal ion complexing agent, analgesic and the like. Due to high stability of methylergometrine maleate and prescription ratio which is selected precisely and verified repeatedly, the methylergometrine maleate injection has more remarkable stability. The preparation method of the methylergometrine maleate injection is easy, in other words, the methylergometrine maleate injection can be produced by a conventional preparation method without any special equipment. Therefore advantages such as industrialization feasibility, high production efficiency, sterility guarantee, low adverse effect, controllable quality and excellent stability are achieved.

The invention discloses a structural silicone adhesive with low modulus and high volume resistivity. The structural silicone adhesive is composed of a component A and a component B according to a volume ratio of 10: 1, wherein the component A is composed of hydroxyl-terminated polymethylsiloxane, a plasticizer and a reinforcing filling material; and the component B is composed of methyl-terminatedpolydimethylsiloxane, pigment carbon black, a silane coupling agent, a chain extender, an active hydrogen sealing agent, a cross-linking agent, a catalyst, an antioxidant, a light stabilizer and a deep curing agent. The structural silicone adhesive with low modulus and high volume resistivity provided by the invention improves the volume resistivity of a conventional structural adhesive from 1015omega.cm to 1016 omega.cm, increases an order of magnitude in the volume resistivity, is applicable to structural assembly of a system with photovoltaic voltage classes of 1500 V, 2000 V and even 3000 V, specifically to structural adhesion assembly of places with high requirements on insulation, such as thin film assemblies, and exerts an effect of structural adhesion.

The invention relates to a method for directly preparing 2,5-dihydroxymethyl tetrahydrofuran from fructose, which comprises the following step: in a water/oil two-phase system, directly converting fructose into the 2,5-dihydroxymethyl tetrahydrofuran by one step under the conditions of 0.5-10 MPa H2 and 80-180 DEG C under the action of a catalyst for 0.5-16 hours. The maximum selectivity of the 2,5-dihydroxymethyl tetrahydrofuran is 72%, and the maximum yield is 56%.

The invention relates to a novel thymalfasin chitosan / beta-cyclodextrin composite microsphere drug delivery system and a preparation method. Chitosan serves as a membrane material, beta-cyclodextrin serves as a clathration material, and a composite microsphere is prepared in a reversed phase suspension-chemical crosslinking method. According to the novel thymalfasin chitosan / beta-cyclodextrin composite microsphere drug delivery system, the composite microsphere carries thymalfasin. According to the novel thymalfasin drug delivery system, the obtained composite microsphere performs good protection and controlled-release functions on the thymalfasin, provides feasibility for oral administration medicines and has good economic benefits and application prospect.

The invention discloses a high-temperature-resistant anti-aging silicone tube which is prepared by squeezing a silicone rubber composite material. The silicone rubber composite material is prepared from methyl vinyl silicone rubber, ethene-acrylic rubber, ethylene-propylene-diene monomer, butadiene rubber, ethene-octylene copolymer, zinc oxide, stearic acid, 2, 5-dimethyl-2, 5-di(tert-butyl-peroxyl) hexane, methyl-tri-(butanone-oxime) silane, triallyl isocyanurate, fumed silica, nano calcium carbonate, attapulgite, lanthanum stearate, cerium hydroxide, hydroxy terminated polydimethylsiloxane, a silane coupling agent, a catalyst and an anti-aging agent. The high-temperature-resistant anti-aging silicone tube is good in high temperature resistance, excellent in anti-aging performance and long in service life.

The invention provides a pharmaceutical composition for treating steatohepatitis and a preparation method of the pharmaceutical composition. The pharmaceutical composition comprises the following components in parts by weight: (a) 1 part of a compound shown in a formula (I); (b) 16-600 parts of a meltable dispersion carrier, wherein the meltable dispersion carrier comprises poloxamer and polyethylene glycol, and the weight ratio of the poloxamer to the polyethylene glycol is 1:(0.5-27); and (c) 0.2-100 parts of non-volatile weak acid. The pharmaceutical composition is beneficial to greatly improving the in-vitro dissolution rate of the compound shown in the formula (I), and meanwhile, the stability of the compound shown in the formula (I) can be ensured due to mild preparation conditions.

The invention provides an azithromycin medicine composition and a preparation method thereof. The azithromycin medicine composition comprises medicine granules containing azithromycin, an isolation layer, a taste masking layer and a taste modifying layer, wherein the isolation layer, the taste masking layer and the taste modifying layer sequentially coat the medicine granules in a form of coating.The isolation layer, the taste masking layer and the taste modifying layer of the azithromycin medicine composition are prepared into coats to coat sequentially coat the medicine granules in the formof coating, so that a medicine component release curve is more gentle, and the occurrence of adverse reactions of gastrointestinal tracts can be reduced effectively on the premise that the efficacy and bioavailability are guaranteed. Meanwhile, the azithromycin medicine composition reduces the dosage of a taste modifying agent, is safer to take by children and keeps a good taste.

The invention belongs to the technical field of chemistry, and particularly relates to a synthetic method of an azithromycin rearrangement impurity R. The method mainly comprises the steps that (3R,4R,5S,6R,9R,10S,11S,12R,13R,15R,Z)-12-[[3,4,6-trideoxy-3-(dimethylamino)-beta-D-wood-pyranose group]oxygen]-6-ethyl-4,5-dihydroxyl-10-[(2,6-dideoxy-3-C-methyl-a-L-nuclear-pyranose group)oxygen]-3,5,9,11,13,15-hexamethyl-7,16-dioxy-2-azabicyclo[11.2.1]cetane-1-alkene-8-ketone(compound III) is subjected to acidification rearrangement, and after refining is conducted, the rearrangement impurity R withthe purity being 99.5% or above is obtained. The synthesized high-purity azithromycin rearrangement impurity R serves as an impurity standard substance of finished production detection, locating and qualification on the impurity are enhanced conveniently, and quality control over azithromycin active pharmaceutical ingredient is improved.

The invention discloses application of binaphthol derivatives in the aspect of active free radical photopolymerization reaction, and relates to the field of controllable active free radical polymerization catalyzed by organic photocatalysts, in particular to an organic catalytic system which takes 1, 1'-bi-2, 2'-naphthol derivatives as organic photocatalysts and generates activity-controllable free radical photopolymerization under visible light. According to the invention, a BINOL polymer is used as an organic photooxidation reduction catalyst, so that rapid reversible equilibrium between dormant species and an active chain can be achieved, the polymerization reaction has controllability, and a novel application method for the BINOL organic polymer in the organic photocatalytic active free radical polymerization is provided while a homopolymer and a block copolymer with characteristics of the controllable molecular weight and the low polydispersity can be prepared; and moreover, the organic catalytic system provided by the invention has the characteristics of high efficiency, low cost and easiness in operation, and the prepared polymer has the characteristics of the controllable molecular weight and the narrow polydispersity, and conforms to the production concept of environment-friendly green production.

The invention discloses an anti-aging PVC (Polyvinyl Chloride) board with excellent thermal stability and a preparation method of the anti-aging PVC board. The anti-aging PVC board comprises the following raw materials in parts by mass: chloroethylene, epoxy compounds, a rare earth catalyst, di-cetyl peroxydicarbonate, modified montmorillonite, nano calcium carbonate, 2-(2-hydroxy-4-hexoxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,2'-methylene-bis(4-tert-butyl-6-benzotriazolyl) phenol, pentaerythritol ester, a dispersing agent and a plasticizer. The PVC board prepared by the preparation method disclosed by the invention is excellent in thermal stability and is difficult to decompose and discolor under light and high temperature conditions, release of toxic gases is reduced, and the service life is prolonged.

The invention discloses a molten resin defoaming method and a spinning forming method. The defoaming method comprises the following steps: S1, feeding; S2, in a vacuum environment, carrying out spinning treatment on molten resin; and S3, in the vacuum environment, carrying out defoaming treatment on the resin subjected to spinning. According to the molten resin defoaming method provided by the invention, the molten resin is jetted into filaments by a spinning process, the specific surface area of the resin filaments is increased, bubbles are extremely easy to escape from the surfaces or the interiors of the resin filaments, and the defoaming effect is remarkable. The invention further provides a spinning forming method, the defoamed resin is spun, the bubbles in resin yarn are remarkably reduced, and the quality of the resin yarn is remarkably improved.