151 results about "Ph gradient" patented technology

Enteric coated stable oral pharmaceutical composition of acid unstable drug. The enteric coating is a bilayer with a pH gradient across its thickness comprising an inner layer of neutral or near neutral pH 7-7.5 and an outer layer of acidic pH 2-6. Also process for preparng the enteric coated stable oral pharmaceutical composition of acid unstable drug. The enteric coating is first carried out at neutral or near neutral pH of 7-7.5 to form an inner layer of neutral or near neutral pH and then at acidic pH of 2-6 to form an outer layer of acidic pH.

The present invention relates to a composition and to a display device having the composition positioned between electrodes. The composition contains: (a) a compound that undergoes a reversible redox reaction to generate a pH gradient between the two electrodes, (b) an indicator dye, (c) a charge transport material, and optionally, (d) a matrix material and (e) an opacifier, and (f) secondary redox couple wherein components (a), (b), and (c) are different from one another and the standard reduction potential of component (a) is less than the standard reduction potential for the other components. Depending on the electric field present between the electrodes, a display image may be generated.

A composition of a rapidly disintegrating buccal dosage form containing a drug, at least one non-effervescent base such as an alkali metal or alkaline earth metal oxide or hydroxide, and a disintegrant. The base regulates the pH gradient to deliver the drug to the buccal, sublingual or oral mucosal membranes at a desired rate of absorption. The composition is micronized for uniform distribution, and the drug is converted from ionized form to unionized form, without the use of an effervescent agent.

The present invention relates to methods of purifying and analyzing preparations of Fc domain containing polypeptides comprising binding said polypeptide to protein A, more particularly to a protein A column, and eluting with a pH gradient elution system. This method enhances separation of aggregates, multimers and modified versions of the protein from the single Fc domain containing polypeptide.

A method for encapsulation of antineoplastic agents in liposomes is provided, having preferably a high drug:lipid ratio. Liposomes may be made by a process that loads the drug by an active mechanism using a transmembrane ion gradient, preferably a transmembrane pH gradient. Using this technique, trapping efficiencies approach 100%, and liposomes may be loaded with drug immediately prior to use, eliminating stability problems related to drug retention in the liposomes. Drug:lipid ratios employed are about 3-80 fold higher than for traditional liposome preparations, and the release rate of the drug from the liposomes is reduced. An assay method to determine free antineoplastic agents in a liposome preparation is also disclosed.

Various embodiments of the present invention are directed to multi-step systems and methods for target-molecule purification that employ column-chromatography-based and / or membrane-filtration-based polishing steps. In one described embodiment of the present invention, a target-protein-containing eluate having a high residual salt concentration is collected from a first chromatography column prepared with an affinity-chromatography resin, loaded onto a second chromatography column prepared with a cation-exchange resin, and eluted from the second cation-exchange column using a buffer in which a time-dependent pH gradient is established. In another described embodiment of the present invention, a partially purified target-protein-containing eluate is collected from a chromatography column and further purified by passing the target-protein-containing eluate through a salt-tolerant anion exchanger.

Methods and apparatus are presented that facilitate electrophoresis of prior-cast, hydratable separation media, usefully immobilized pH gradient (IPG) strips. The method exploits the swelling of prior-cast, hydratable separation media upon rehydration to help lodge the media in an enclosing member that permits spaced electrical communication with the enclosed separation media. The electrical communication permits a voltage gradient to be established in the enclosed separation medium sufficient to effect separation of analytes therein. Cassettes, buffer cores, electrophoresis systems and kits are presented for effecting the methods of the invention.

The invention provides a cabazitaxel liposome injection and a preparation method thereof. The cabazitaxel liposome injection comprises cabazitaxel, phosphatide, cholesterol, and mannitol or glucose, and can be prepared through the vacuum film condensation method, the rotary evaporation method, reverse evaporation method, high-pressure homogenization method, and pH gradient method. The cabazitaxel liposome injection has the advantages of reduced toxicity, convenience in clinic, and improved biological availability, and furthermore avoids the a plurality of changes of liposome during the storage process, such as oxidation and hydrolysis of phosphatide, agglomeration and fusion of liposome, and the like, wherein the changes can cause the leakage of coated substance. The invention provides a cabazitaxel liposome which has a good stability and is enough stable in the storage period.

Various embodiments of the present invention are directed to multi-step systems and methods for target-molecule purification that employ column-chromatography-based and / or membrane-filtration-based polishing steps. In one described embodiment of the present invention, a target-protein-containing eluate having a high residual salt concentration is collected from a first chromatography column prepared with an affinity-chromatography resin, loaded onto a second chromatography column prepared with a cation-exchange resin, and eluted from the second cation-exchange column using a buffer in which a time-dependent pH gradient is established. In another described embodiment of the present invention, a partially purified target-protein-containing eluate is collected from a chromatography column and further purified by passing the target-protein-containing eluate through a salt-tolerant anion exchanger.

Accordance to various embodiments, there are methods of separating molecules, devices, and method of making the devices. The method of separating molecules can include providing a nanofluidic device including a plurality of nanochannels on a top surface of a substrate, wherein each of the plurality of nanochannels has a first end and a second end and extends from the top surface into the substrate. The nanofluidic device can also include a dielectric layer disposed over each of the plurality of nanochannels, an inlet at the first end of the plurality of nanochannnels, an outlet at the second end of the plurality of nanochannels, and an optically transparent cover disposed over the plurality of nanochannels to form a seal. The method of separating molecules can further include providing a solution in the plurality of nanochannels through the inlet and creating a longitudinal pH gradient along each of the plurality of nanochannels.

The present invention provides methods for purifying a polypeptide comprising a CH2 / CH3 region, comprising binding the polypeptide to Protein A and eluting with a pH gradient starting at a low pH.

The present invention relates to a method of isolating target compounds from a liquid, which comprises at a first pH, contacting the liquid with a separation medium that exhibits surface-localised pH-responsive polymers in to adsorb the target compound via hydrophobic interactions; and adding an eluent, which is of a second pH and provides a conformational change of said pH-responsive polymers to release said compounds. The elution is advantageously performed by a pH gradient and / or by a salt gradient.

The present invention relates generally to a process that helps alleviate the pH gradient between anode and cathode compartments in any biological fuel cell or electrolytic cell configuration in which a pH gradient between anode and cathode is limiting the voltage efficiency. By providing acid to the cathode compartment in the form of CO2, the pH gradient is reduced and voltage efficiency and power output are increased. In one embodiment, carbon dioxide produced in the anode chamber is recycled to the cathode chamber.

The present invention provides an apigenin vesiculation preparation and its preparation process. Said preparation composition includes (by wt%) 0.25%-20% of apigenin, 40%-90% of non-ionic surface active agent, 8.7-48.8% of cholesterol and 2%-20% of lyophilization protection agent. The described non-ionic surface active agent can be Span-20, Span-40, Span-60, Span-80, Tween-20, Tween-60, Tween-80, benzozir, maizir, poloxamer or their mixture. Said invention can be made into preparations of injection, nose drops, ointment and oral liquor, etc, and can be prepared by adopting ethyl alcohol injection method, film dispersion method, inversed phase evaporation method, hydration method, extrusion method, mechanical method and pH gradient method.

The invention provides a microorganism electrochemical system capable of realizing electricity generation, hydrogen generation and sewage treatment simultaneously, comprising an electrolyzer which is divided into an anode chamber and a cathode chamber by a bipolar membrane, wherein the anode chamber and the cathode chamber are internally provided with an anode and a cathode respectively; the anodes and the cathodes are connected with a resistor by guide lines; each anode is formed by electricity-generating microorganisms and an anode substrate; each cathode is made of an electrochemically inert metal titanium, platinum or carbon material; the anode chamber is internally provided with sewage containing organic pollutants; and the cathode chamber is internally provided with a strong acid solution. In the system, a diaphragm technology is adopted to separate pH gradients of the anode chamber and the cathode chamber; a hydrogen evolution potential of the cathode is improved, and the activity of the organisms in electricity-generating microorganism oxidized sewage of the anode is maintained at the same time; the hydrogen is generated at the cathode at the same time of treating the organisms in the sewage of the anode; and because the cathode potential is improved, and the reaction can be generated spontaneously to output the electricity externally.

Provided herein are novel methods of making liposomally encapsulated drugs using reverse pH gradients and optimizing internal buffer compositions. Further provided herein are liposome compositions including an active pharmaceutical ingredient and uses thereof to treat a variety of diseases (e.g. cancer, inflammatory, neurological and cardiovascular diseases).

The present invention relates to a method of purifying a protein of interest from its fusion analog, comprising obtaining a protein solution comprising a protein of interest and its fusion analog; adjusting the pH and / or ionic strength of the protein solution with an appropriate buffer for use with a Hydrophobic Charge Induction Chromatograph (HCIC) resin, contacting the protein solution and HCIC resin column to allow binding of the protein of interest and its fusion analog, washing the resin and eluting the protein of interest from the resin by a pH gradient; wherein the protein of interest is substantially free of its fusion analog.

This invention improves the PAMPA (parallel artificial membrane permeability assay) method used in pharmaceutical, biotechnological, and agrochemical R&D. This new high-throughput method and apparatus for measurement of permeability and membrane retention of compounds overcomes shortcomings of prior art and includes sensitivity and speed enhancing reagents. The phospholipid membranes used here consist of 10–74% wt / vol soybean lecithin extract dissolved in dodecane. Concentrations are measured by direct UV spectroscopy. To reduce membrane retention, surfactants, cyclodextrins, or water-soluble lipophilic polymers with low UV absorption are used in the acceptor comparment of the permeation cells and create an artificial sink state. A pH gradient established between donor and acceptor solutions creates a secondary sink state. This “double-sink” makes successful modeling of passive-diffusion transport of molecules possible. By accelerating transport of certain molecules, it shortens measurement time and increases assay throughput. A new permeability equation accounts for the “double-sink” condition as well as membrane retention.

The invention discloses levocarnitine liposomes injection, which is characterized by comprising the following active ingredients in parts by weight: 1 part of levocarnitine, 3-15 parts of soybean lecithin, 0.4-7.5 parts of cholesterol and 0.02-1 part of antioxidant, and a pharmaceutically acceptable carrier, wherein, the antioxidant is one or more of L-cysteine, thiourea, vitamin E and butylated hydroxyanisole and is most preferably the vitamin E. The invention also discloses a preferable preparation method of the levocarnitine liposomes injection, namely ammonium sulphate pH gradient method.The invention provides levocarnitine liposomes injection which has excellent stability, high entrapment rate and low leakage rate in the process of long-term storage. The acute toxicity tests, unusualtoxicity tests and heat source tests adopting the levocarnitine liposomes injection all conform to the specifications and are applicable to industrialized production.

Disclosed is a novel microfluidic device enabling on-chip implementation of a two-dimensional separation methodology. Previously disclosed microscale immobilized pH gradients (IPG) are combined with perpendicular polyacrylamide gel electrophoresis (PAGE) microchannels to achieve orthogonal separations of biological samples. Device modifications enable inclusion of sodium dodecyl sulfate (SDS) in the second dimension. The device can be fabricated to use either continuous IPG gels, or the microscale isoelectric fractionation membranes we have also previously disclosed, for the first dimension. The invention represents the first all-gel two-dimensional separation microdevice, with significantly higher resolution power over existing devices.

Compositions and methods of preparing a graft construct comprising aligned collagen fibrils, wherein the construct is anisotropic, are described. The construct is prepared by application of an electrochemical field and a pH gradient to solutions containing collagen. In accordance with this method, collagen aligns at its isoelectric point to form anisotropic constructs.

The invention belongs to the medicine technical field, relates to epirubicin hydrochloride liposome and a preparation method. The liposome comprises epirubicin hydrochloride and neutral phospholipid and cholesterol and / or negative charge phospholipids and / or long-circulating phospholipids and buffer solution, and actively carries drug with a PH gradient method or an ammonium sulphate gradient method; the entrapment rate of the achieved liposome is more than 90%, to make smaller volume contain more main drug component of epirubicin. Compared with the exiting techniques, the epirubicin hydrochloride liposome and the preparation method has the advantages of high drug content, high bioavailability, long internal circulation time, low toxic and side effect and other advantages; besides, the production cost can be reduced obviously, the epirubicin hydrochloride liposome is more suitable for industrial production after being made into lyophilized preparation. The liposome is clinically suitable for the tumor therapy, in particular to the tumor therapy for children.

The invention relates to a method for adopting a pH gradient elution method to synchronously separate triterpenoid saponins and licorice flavonoid. Eluent taking triterpenoid saponins as a main ingredient and eluent containing licorice flavonoid and other useful ingredients are obtained respectively through preparation of a sample loading solution, pretreatment of macroporous resin, loaded sample adsorption, preheating and application interlayer chromatography for pH gradient elution and adopting sodium carbonate solution, sodium bicarbonate solution or sodium hydroxide solution which are different in alkalinity. Yield of glycyrrhizic acid can be increased by 2-4 times when compared with that of a method taking ethanol solution as eluant, ethanol consumption and consumption caused by ethanol recovery are lowered, yield of glycyrrhizic acid can be increased by more than 60% to greatest extent when compared with that of a normal-temperature elution process, an experimental device which is simple, convenient and easy is provided for non-normal-temperature column separation of temperature-sensitive special ingredients in the field of chemistry, chemical engineering and pharmaceuticals, and the method has popularization value.

The invention discloses a preparing method and application for an integral immobilized pH gradient; the preparing method comprises the following steps: a series of solution which consist of acid, alkali and neutral monomer and have different pH values are prepared, each solution is polymerized so as to obtain a pH gradient, a plurality of gradients are combined to obtain a pH gradient with wide range, the pH gradients are fixed in a column container by adopting an in-situ polymerization method or a method for polymerization firstly and immobilization then, and so the integral immobilized pH gradient is obtained; compared with the prior art, the method of the invention can conveniently prepare the immobilized pH gradient with any range of 1 to 14 without using commercial amphoteric electrolyte, and has simple operation and low cost; the prepared pH gradient is used for separating the amphoteric electrolytes of protein and polypeptide, etc. by isoelectric focusing, has stable gradient and high resolution, can be used repeatedly and is applicable to purifying equipment.

A specified proton concentration in a volume (80) is produced by passing a controlled electrophoresis current through an adjacent electrophoresis volume (28) between a working electrode (26) and a counter electrode (24). An array of such volumes with specified proton concentration is used to provide the pH gradient for isoelectric focusing.

The invention provides a preparation method of a probiotic and aloe mask, which is characterized by preparing a fermentation stock solution from aloe vera raw juice, glucose and water according to certain proportions and adding probiotics for performing co-fermentation. By setting different temperature gradients and pH gradients, after viable count, optimal fermentation conditions are determined; an aloe and probiotic fermentation solution is adopted to carry out an antibacterial test so as to determine an antibacterial effect, such as propionibacterium acnes; and meanwhile, by determining an antioxidant index, the antioxidant ability of the aloe and probiotic fermentation solution is determined, such as determination of DPPH radical scavenging ability, determination of iron ion chelating ability and determination of total reducing force. According to the product, the aloe and probiotic fermentation solution is mixed with cosmetic auxiliary materials in proportion so as to be processed into a pasty mask, and after sensory index testing, skin irritation testing and trial effect testing, the safety and functionality of the product are determined, so that the aims of skin protection and health care are achieved.

The invention provides a chloroquine liposome lyophilized powder for injection, comprising (by weight parts) the chloroquine or the salt formed by the chloroquine and acid 1part, phospholipid 2-100 parts, cholesterol 1-35 parts, vitamin E 0.5-5.0 and excipients. The preparation method comprises two steps, including the preparation of blank liposome, and the preparation of drug-carrying liposome through the pH gradient method. The injection has the advantages of reasonable design, wide carrier selection range, high drug entrapment efficiency, and good stability. The preparation method has the advantages of easy operation, low cost, and good controllability and repeatability.

Herein is reported a method for determining the presence of antibody-Fab-FcRn interaction in an antibody-Fc-FcRn complex influencing the in vivo half-life comprising the steps of a) determining the retention time of the antibody on an FcRn affinity chromatography column with a positive linear pH gradient elution in the presence of a first sodium chloride concentration, and b) determining the retention time of the antibody on an FcRn affinity chromatography column with a positive linear pH gradient elution in the presence of a second sodium chloride concentration, whereby the presence of antibody-Fab-FcRn interaction in an antibody-Fc-FcRn complex influencing the in vivo half-life is determined if the retention time determined in step a) and the retention time determined in step b) are substantially different.

The invention relates to an Off-Adhesive free flow electrophoresis coupling chip and a making method thereof, belonging to the technical field of microfluidic chip manufacture. The chip comprises a chip substrate, an electrode and a separating chamber, wherein an immobilized pH gradient adhesive tape area and hard substrates for fixing and embedding of immobilized pH gradient adhesive are arranged at the tail end of the separating chamber. The method comprises the following steps: arranging a rectangular area for embedding of the immobilized pH gradient adhesive tape at the tail end of the separating chamber of the other substrate, then aligning the chip substrate with another substrate, carrying out sealing connection on the two substrates and the electrode according to a combined sealing method of the free flow electrophoresis chip to form a free flow electrophoresis chip, arranging the chosen immobilized pH gradient adhesive tape at the rectangular slotting area of the chip, and pressing and fixing the immobilized pH gradient adhesive tape by using the other hard substrate for using. The chip not only solves the defects of the free flow electrophoresis chip and Off-Adhesive electrophoresis technologies, but also inherits the advantages of the two technologies; and the chip has simple manufacturing method, and the immobilized pH gradient adhesive tape is replaceable.