1806 results about "Glycolic acid" patented technology

An acid fracturing method is provided in which the acid is generated in the fracture by hydrolysis of a solid acid-precursor selected from one or more than one of lactide, glycolide, polylactic acid, polyglycolic acid, a copolymer of polylactic acid and polyglycolic acid, a copolymer of glycolic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, and a copolymer of lactic acid with other hydroxy-, carboxylic acid or hydroxycarboxylic acid-containing moieties. The solid acid-precursor may be mixed with a solid acid-reactive material to accelerate the hydrolysis and/or coated to slow the hydrolysis. Water-soluble liquid compounds are also given that accelerate the hydrolysis. The method ensures that the acid contacts fracture faces far from the wellbore.

The present invention relates to a haemostatic multilayer bandage that comprises preferably a thrombin layer between two fibrinogen layers. The dressing may contain other resorbable materials such as glycolic acid or lactic acid based polymers or copolymers. The inventive haemostatic bandage is useful for the treatment of wounded tissue.

Downhole tools for use in oil and gas production which degrade into non-toxic materials, a method of making them and methods of using them. A frac ball and a bridge plug comprised of polyglycolic acid which can be used in fracking a well and then left in the well bore to predictably, quickly, and safely disintegrate into environmentally friendly products without needing to be milled out or retrieved.

This invention is directed to the field of medical implants, and more specifically to biodegradable injectable implants and their methods of manufacture and use. The injectable implants disclosed herein comprise glycolic acid and bio-compatible/bio-absorbable polymeric particles containing a polymer of lactic acid. The particles are small enough to be injected through a needle but large enough to avoid engulfment by macrophages. The injectables of this invention may be in a pre-activated solid form or an activated form (e.g., injectable suspension or emulsion).

Non-woven fibrous scaffolds made by electrospinning from the synthetic biodegradable polymer such as, for example, poly(lactic-co-glycolic acid) (PLGA) and natural proteins, such as, for example, gelatin (denatured collagen) and elastin and a method of making thereof.

The present invention provides a method of treating glaucoma, the method comprising the step of placing a polymer in an eye of a patient, which biologically degrades over a period of time to release biodegradants, which are effective to lower the intraocular pressure of the patient, thereby treating glaucoma. Said polymer is preferably selected from the group consisting of polymers of lactic acid, glycolic acid and/or mixtures thereof. More preferably the polymer is a copolymer of lactic acid and glycolic acid, e.g. a copolymer comprising from 50 to 100% lactic acid and from 0 to 50% glycolic acid, by weight.

Absorbable polyurethanes, polyamides and polyester urethanes prepared from at least one compound selected from:

or the diamines and diisocyanates thereof, wherein each X represents a member independently selected from —CH₂COO— (glycolic acid moiety), —CH(CH₃)COO— (lactic acid moiety), —CH₂CH₂OCH₂COO— (dioxanone), —CH₂CH₂CH₂CH₂CH₂COO— (caprolactone moiety), —(CH₂)_yCOO— where y is one of the numbers 2, 3, 4 or 6-24 inclusive, and —(CH₂CH₂O)_z′CH₂COO— where z′ is an integer between 2 and 24, inclusive; each Y represents a member independently selected from —COCH₂O— (glycolic ester moiety), —COCH(CH₃)O— (lactic ester moiety), —COCH₂OCH₂CH₂O— (dioxanone ester), —COCH₂CH₂CH₂CH₂CH₂O— (caprolactone ester), —CO(CH₂)_mO— where m is an integer between 2, 3, 4 or 6-24 inclusive, —COCH₂O(CH₂CH₂O)_n— where n is an integer between 2 and 24, inclusive; R′ is hydrogen, benzyl or an alkyl group, the alkyl group being either straight-chained or branched; p is an integer between 1 and 4, inclusive; and Rn represents one or more members selected from H, alkoxy, benzyloxy, aldehyde, halogen, carboxylic acid and —NO₂, which is attached directly to an aromatic ring or attached through an aliphatic chain. Absorbable polymers prepared from these compounds are useful for drug delivery, tissue engineering, tissue adhesives, adhesion prevention and other implantable medical devices.

The present invention is directed to a novel poly(diol citrates)-based nanocomposite materials created using completely biodegradable and biocompatible polymers that may be used in tissue engineering. More specifically, the specification describes methods and compositions for making and using nanocomposites comprised of citric acid copolymers and polymers including but not limited to poly(L-lactic acid) (PLLA) and poly(lactic-co-glycolic acid) (PLGA).

The invention relates to acid solution used for processing the magnesium alloy surface. The acid solution is water solution which contains acids, inhibitor and wetting agent, wherein, the acids are first acids or mixture of first acids and second acids; the first acids are selected from one type or a plurality of types among citric acids, oxalic acids, tartaric acids, methanoic acids, acetic acids, metacetonic acids, butyric acids, glutaric acids, phenylformic acids, benzene dicarboxylic acids, lactic acids, glycolic acids, glyoxylic acids and amino acids; and the second acids are hydrochloric acids and/or nitric acids. By adoption of the acid solution, the magnesium alloy surface can be fully activated; the membranous layer of a converting film which is formed on the magnesium alloy surface after chemical conversion process is compact, has erosion resistance and good binding force with a paint film. Moreover, the method is a environment-friendly method for processing the magnesium alloy surface.

There is provided a method to modify biodegradable polymers using the direct reaction of a biodegradable polymer in a vinyl monomer and may take place in the presence of initiators. The initiator may be free radical initiators, heat, ionic initiators, UV irradiation, ionizing irradiation and other high energy irradiation. Suitable biodegradable polymer include polycaprolactone, poly(lactic acid), poly(glycolic acid) and poly(lactic-co-glycolic acid). Suitable vinyl monomers include acrylates, methacrylates and the like.

A composition comprising an active ingredient selected from the group of 5-aminolevulinic acid or a pharmaceutically acceptable salt or derivative thereof; and an aqueous carrier comprising at least one absorption enhancer, an anesthetic, hyaluronic acid and at least one acid selected from the group consisting of glycolic acid and lactic acid. The composition is useful in a photodynamic method of treating skin disorders.

Genetically engineered organisms for production of PHA copolymers containing 2-hydroxyacid monomers and the methods of making and using thereof have been developed. The copolymers containing 2-hydroxyacid monomers can be synthesized via biosynthesis by the action of a PHA polymerase in a living cell. By changing the genetic background of the cells, one can control specific metabolic pathways allowing control of the level of glycolic acid co-monomer in the PHA polymer.

The present invention relates to a nano-calcium phosphates/collagen composite that mimics the natural bone, both in composition and microstructure, as well as porous bone substitute and tissue engineering scaffolds made by a complex of said composite and poly(lactic acid)(PLA) or poly(lactic acid-co-glycolic acid)(PLGA). The invention also relates to the use of said scaffold in treating bone defect and bone fracture.

A glycolic acid copolymer comprising (a) 80 to less than 95% by mole of glycolic acid monomer units, (b) 5.0 to 20.0% by mole of non-glycolic, hydroxycarboxylic acid monomer units, and (c) 0 to 0.10% by mole of diglycolic acid monomer units, the non-glycolic, hydroxycarboxylic acid monomer units (b) constituting a plurality of segments each independently consisting of at least one monomer unit (b), wherein the segments have an average chain length of from 1.00 to 1.50 in terms of the average number of monomer unit or units (b), the total of the components (a), (b) and (c) being 100% by mole, the glycolic acid copolymer having a weight average molecular weight of 50,000 or more.

The invention relates to a PLA/PLGA shell-core microsphere prepared by solid-in-oil-in-water in the technical field of pharmacy and a preparation method thereof. The microsphere comprises 0.01 to 50 percent of medicine, 20 to 99.99 percent of polylactic acid and/or polylactic acid-glycolic acid, or/and 0 to 30 percent of pharmaceutical excipient (weight percentage). The method comprises the steps of: adding medicine particles into a PLA and/or PLGA organic solution to be emulsified, then selecting a hydrophilic organic solvent to re-emulsify to form unhardened balls, finally hardening in another large oil phase, removing the organic solvent and collecting micropheres. The method overcomes the disadvantages of low envelope rate of the prior W/O and W/O/W, serious burst release of S/O/O, and environmental pollution, controls the grain diameter of the microsphere according to the need, does not pollute the environment, and can be applied to the preparation of slow release or controlled release microspheres of various medicines and adjuvants of vaccines.

The disclosed is a biodegradable copolymer, an amphiphilic diblock copolymer, composed of a hydrophilic segment and a hydrophobic segment. The hydrophilic segment is an endcapped PEG or derivatives thereof. The hydrophilic segment is a random polymer polymerized of lactone or cyclic C₃-C₆ molecule and lactic acid/glycolic acid. There is no coupling agent between the hydrophilic and hydrophobic segments, and the biodegradable copolymer is formed by one-pot ring-opening polymerization. The biodegradable copolymer can be dissolved in water to form a thermosensitive material having a phase transfer temperature of 25 to 50° C., thereby being applied to biological activity factor delivery, tissue engineering, cell culture and biological glue.

The polylactic acid film contains polylactic acid 85-98 wt% and medical plasticizer 2-15 wt%, the polylactic acid may be poly L-lactic acid, poly DL-lactic acid, lactic acid-glycolic acid copolymer or the copolymer of poly L-lactic acid and poly DL-lactic acid with molecular weight of 20-1500 KDa, and the medical plasticizer is tributyl citrate, tributyl acetylcitrate, polyethylene glycol or lactic acid oligomer. The polylactic acid composition of the present invention has excellent flexibility, may be used in introducing the growth of hard and soft tissues in repairing cleft palate or as regenerating film, and introducing the regeneration of bone tissue.