46 results about "PH-sensitive polymers" patented technology

Oral formulations of pharmaceuticals are provided with enhanced bioavailability by targeting specific regions of the gastrointestinal tract. Particularly, water soluble and acid-labile drugs such as cytidine analogs (e.g., decitabine) and 2'-deoxyadenosine analogs (e.g., pentostatin) are formulated with pH-sensitive polymers so that these drugs are preferably absorbed in the upper regions of the small intestine, such as the jejunum. In addition, drugs with poor oral bioavailability such as camptothecin compounds (e.g., 9-nitro-camptothecin) can also be formulated using similar strategies in order to significantly improve their oral bioavailability. These formulations can be used to treat a wide variety of diseases or conditions, such hematological disorders, benign tumors, cancer, restenosis, inflammatory diseases, and autoimmune diseases.

The present invention discloses coating compositions with taste masking property, comprising a blend of pH sensitive polymers and optionally a pH independent polymer or a blend of the pH sensitive polymer and pH independent polymer used for taste masking of highly bitter drugs. The pH sensitive polymers used comprise the acid soluble polymers and the enteric polymers. The process for the preparation of taste masked pharmaceutical compositions of the bitter drugs comprising the said coating compositions is disclosed. The concomitant use of the polymers inhibits the release of the bitter drug at the pH of saliva. The said coating compositions deliver substantial amount of the bitter drug immediately with improved palatability.

Formulations have been developed to improve the solubility of corticosteroids such as fluticasone proprionate in a composition designed to achieve localized release of the drug in the small intestine and/or colon. In one embodiment, solid dispersions of fluticasone are prepared wherein the drug is blended with or coated onto a highly water soluble substrate such as nonpareil (sugar beads) then coated with a layer of polymer soluble in small intestinal fluid, then coated with an enteric coating. The inner polymer layer controls release of the drug, and the enteric coating, a pH sensitive polymer that is broken down in the ileum and colon, controls localized release of drug at various sites within the gastrointestinal tract. The multilayer pharmaceutical composition can be in the form of pellets, tablets compressed from pellets or pellets packed into capsules. The release profile of the drug can be manipulated by (1) altering size or shape (i.e., surface area) and solubility of the inert substrate; (2) the ratio of drug to polymer, the polymer composition and solubility, the porosity of the polymer; (3) the drug form (i.e., free base or salt, or which salt); and the thickness and/or surface area of the drug/polymer and/or enteric coating. In a preferred embodiment, the composition is administered orally. This may also be packaged to provide for an escalating or tapering dosage.

Mixed micelles containing poly(L-histidine-co-phenylalanine)-poly(ethylene glycol) block copolymer and poly(L-lactic acid)-poly(ethylene glycol) block copolymer are a pH-sensitive drug carrier that release the drug in an acidic microenvironment, but not in the blood. Since the microenvironment of solid tumors is acidic, these mixed micelles are useful for treating cancer, including those cancers exhibiting multidrug resistance. Targeting ligands, such as folate, can also be attached to the mixed micelles for enhancing drug delivery into cells. Methods of treating a warm-blooded animal with such a drug are disclosed.

This present invention is concerned with novel solid dispersion pharmaceutical compositions for preparation of composition which is comprised of a compound with poor water solubility (a weakly basic, neutral and/or non-ionizable, or a weakly acidic compound), water-soluble polymer(s), pH-sensitive polymer(s) (either enteric polymer or gastric-soluble polymer that is soluble at gastric fluid and insoluble at intestine pH range such as Eudragit E), and/or pharmaceutical acceptable surfactant(s) that would improve the solubility/dissolution of the compound in aqueous media of both low and neutral pHs and provide a relative pH-independent dissolution profile.

The present invention provides a solid molecularly dispersed composition comprising a poorly water soluble and weakly basic azole antifungal compound and a pH sensitive polymer, pharmaceutical compositions, comprising the solid molecularly dispersed composition of the invention and methods of treating and/or preventing a fungal infection in a patient in need thereof comprising orally administering a pharmaceutical composition comprising a composition of the invention to a patient in need thereof. Preferably the antifungal, compound is posaconazole, and the pH sensitive polymer is HPMCAS.

The invention discloses a pH-sensitive dentritic polymer drug carrier. The structure of the drug carrier is one of the following: (1) A-B-C, (2), (3) A-B-C-D and (4), wherein A is dentritic polymer core comprising repeated groups, B is pH-sensitive polymer, C is hydrophilic polymer and D is targeting molecule. The pH-sensitive dentritic polymer has a nano-grade grain diameter, and can be used for coating antitumor drug. Besides, the pH-sensitive dentritic polymer has strong tumor targeting effect in vivo, thereby releasing drug quickly after reaching the tumor position.

The invention belongs to the field of medicinal preparations, and relates to a tumor-targeting pH-sensitive polymeric micelle composition, and especially relates to a pH-sensitive polymeric micelle composition encapsulating a poorly-soluble anti-tumor medicine. The tumor-targeting pH-sensitive polymeric micelle composition is constructed by employing biologically-compatible pH-sensitive amphiphilic block polymer and an amphiphilic polymer connected with a targeting ligand or an antibody in a certain ratio, and the composition encapsulates a poorly-soluble anti-tumor medicine. Experiments prove that the polymeric micelle composition has pH-dependent release characteristic, is accumulated in tumor tissue in a high concentration, has specifically targeting inhibiting effect on growth of tumor cells, and provides a novel carrier and preparation strategy for poorly-soluble anti-tumor medicines.

The present invention discloses the pH-sensitive nanoparticles composed of pH-sensitive polymer, hydrophobic material, internal stabilizer, external stabilizer content and insulin drug. The present invention also includes a method for preparation of pH-sensitive nanoparticles, in particular, a multiple emulsions solvent evaporation method. The pH-sensitive nanoparticles of the present invention show good pH-sensitive property with 100-300 nanometer particle size. Significant decrease in blood glucose level is observed in streptozotocin (STZ)-induced diabetic rats and the bioavailability of insulin is more than 10% after oral administration of the insulin-loaded pH-sensitive nanoparticles.

The invention belongs to the field of medicinal preparations, relates to a pH-sensitive polymeric micelle composition resisting tumor drug resistance, and especially relates to a pH-sensitive polymeric micelle composition resisting tumor drug resistance and encapsulating a poorly-soluble anti-tumor medicine. The pH-sensitive polymeric micelle composition resisting tumor drug resistance is constructed by employing two kinds of biologically-compactable pH-sensitive amphiphilic block polymer and an amphiphilic polymer D-alpha-tocopherol polyethyleneglycol succinate (TPGS) as a P-gp inhibitor in a certain ratio, and encapsulates a poorly-soluble anti-tumor medicine. Experiments prove that the polymeric micelle composition has pH-dependent release characteristic, is accumulated in tumor tissue in a high concentration, has specifically targeting inhibiting effect on growth of tumor cells generating drug resistance because of over expression of P-glycoprotein, and provides a novel carrier and preparation strategy for poorly-soluble anti-tumor medicines and reversing of drug resistance of tumor cells.

The present invention discloses pharmaceutical compositions comprising of pH sensitive polymers used for taste masking highly bitter drugs. The pH sensitive polymer acts as a reverse enteric coating, which is soluble in the acidic pH range 1.0 to 3.0 normally found in the stomach but is insoluble in the pH range 3.5 to 7 thus inhibiting the release of the bitter drug at the pH of saliva and also at the pH of reconstitution medium in case of liquid orals.

The invention discloses a preparation and application of an intelligent virus molecular imprinting resonance light sensor based on a metal organic framework. According to the preparation method, a metal organic framework material is used as a supporting body for the first time, and a pH sensitive polymer is an imprinting layer material, so that the molecular imprinting resonance light sensor for detecting viruses is prepared. Due to the fact that the specific surface area of the metal organic framework material is large, more binding sites can be provided; and meanwhile, the pH sensitive polymer has the property of intelligently responding to a pH value so that adsorption and elution of virus macromolecules can be realized more conveniently and more efficiently. Experimental results show that the sensor has good selectivity to template molecules and has a wide linear range, and the detection limit reaches 0.1 pM; the imprinted polymer can be recycled; and finally, the sensor is simpleto prepare, the detection process is simple and convenient to operate, powerful means for detection and diagnosis of the viruses are provided, and an important application prospect is achieved.

Salt formulations, which are resistant to moisture and cooking conditions, are described herein. The formulations provide particles of micronutrients and vitamins encapsulated within heat resistant pH-sensitive water-insoluble polymers, which are packaged within a salt shell. The pH-sensitive, water-insoluble, thermally stable materials stabilize the micronutrients, particularly at high temperatures, such as during food preparation and cooking, and release the micronutrients at the desired locations such as the stomach, small intestine, etc. Preferred pH-sensitive polymers release at a low pH, less than the pH present in the stomach. The particles can be used to deliver daily-recommended doses of micronutrients simultaneously with salt, eliminating the need for vitamin pills. This is particularly important in populations suffering from severe malnutrition.

The present invention is directed to a delayed release pharmaceutical composition in solid dosage form comprising a core comprised of a therapeutically effective amount of drug, e.g., mesalamine, and a pH sensitive coating comprising a mixture of two different pH sensitive polymers, the first pH sensitive polymer dissolves in an aqueous solution at a pH of about 7 or greater and the second pH sensitive polymer dissolves in an aqueous solution at a pH of about 6 or greater, wherein the weight ratio of the first pH sensitive polymer to the second pH sensitive polymer ranges from about 2:1 to about 4:1 and the percent weight gain resulting from the addition of the pH sensitive coating ranges from about 8% up to and including 15% by weight of the core, including any subcoating.

A degradable polymer with pH sensitivity of tumor tissues is a compound in the structure in the formula, wherein the formula is shown in the description, n is greater than or equal to 150 but less than or equal to 420, and n is an integer. The pH sensitive polymer provided by the invention as a drug-loading micelle has the characteristics that (1) the polymer is truly nanoscale (less than 200 nm) and is very uniform and stable; (2) multi-target technology (which overcomes the deficiencies of single targeting) comprises natural targeting of a long-circulating nanoparticle and pH sensitive physical and chemical targeting, so that tumor targeting is sufficiently obtained; (3) the polymer is large drug loading capacity and good in stability, and the treatment cost is lowered and the side effects generated by free drug release; (4) the drug is quickly released in a tumor tissue to obtain a local high concentration so as to quickly kill the cancer cells, and drug resistance is not easily generated; and (5) the polymer is less in distribution in normal tissues and few in side effects as a result of high tumor targeting; even if a small amount of polymer reaches the non-tumor parts, the drug is nearly not released or the release rate is less as a result of pH sensitivity, so that the polymer is few in side effects.

The invention discloses a hydrazide pH sensitive polymer. The hydrazide pH sensitive polymer comprises the following raw materials: acrylic acid, methyl acrylate, an initiator, hydrazine hydrate, an organic phase and water, wherein the molar ratio of acrylic acid to methyl acrylate is 1: 10 to 10: 1, the molar ratio of hydrazine hydrate to methyl acrylate is 1: 10 to 10: 1, the addition amount of the initiator is 0.02-2%w/v, and the volume ratio of the organic phase to a water phase is 1: 10 to 10: 1. The hydrazide pH sensitive polymer disclosed by the invention is prepared by steps of copolymerizing acrylic acid and methyl acrylate and then carrying out a hydrazine reaction through hydrazine hydrate, wherein the content of hydrazide is obviously higher than the content of hydrazide in a commercialized hydrazide material; the reaction between a hydrazide functional group in the hydrazide pH sensitive polymer and an aldehyde group in oxidized glycopeptide is covalent binding, and the enrichment specificity of glycopeptide can be provided; the hydrazide pH sensitive polymer is in a dissolved state in a system with a pH value of higher than 4, and the phase homogeneity of the reaction of the functional group hydrazide and the aldehyde group of the glycopeptide can be realized, thus increasing the reaction speed and the glycopeptide enrichment efficiency.

The invention discloses a pH-sensitive degradable polymer, and a preparation method and application thereof. The polymer is the compound with the following structure as shown in figure, n is not larger than 410 and not smaller than 140, and n is an integer. The pH-sensitive polymer as a medicine carrying micelle has the characteristics that (1), nanoscale is truly realized (smaller than 200nm), and uniformity and stability are high; (2) a multi-targeting technology is realized (defects of mono-targeting are overcome), and comprises natural targeting of long circulation nano particles and pH-sensitive physical chemistry targeting, and tumor targeting is fully obtained; (3) medicine carrying amount is larger, stability is good, treatment cost is reduced and side effects generated by release of free medicine are reduced; (5) the polymer has little distribution in normal tissues due to high tumor targeting, and has very small side effects; even a small amount of polymer arrive at a non-tumor position, the medicine is barely released or very small in release rate due to pH sensitivity and the side effects are very small.