51 results about "Poly d l lactide" patented technology

A process for the production of polylactide, the stages of which for the production and purification of lactide, starting from an aqueous solution of lactic acid or of its derivatives, includes evaporation of water with formation of oligomers, depolymerization to give lactide, condensation and then crystallization of the crude lactide product to give purified lactide, aqueous treatment of the residual fractions from the crystallization and polymerization of purified and / or prepurified lactide to give polylactide in an extruder and in the presence of catalysts. An alternative process includes carrying out the aqueous treatment before the crystallization.

The present invention provides a composition comprising: (a) dielectric material; and (b) porogen comprising at least two fused aromatic rings wherein each of the fused aromatic rings has at least one alkyl substituent thereon and a bond exists between at least two of the alkyl substituents on adjacent aromatic rings. Preferably, the dielectric material is a composition comprising (a) thermosetting component comprising (1) optionally monomer of Formula I as set forth below and (2) at least one oligomer or polymer of Formula II as set forth below where Q, G, h, I, I, and w are as set forth below and (b) porogen. Preferably, the porogen is selected from the group consisting of unfunctionalized polyacenaphthylene homopolymer, functionalized polyacenaphthylene homopolymer, polyacenaphthylene copolymer, polynorbornene, polycaprolactone, poly(2-vinylnaphthalene), vinyl anthracene, polystyrene, polystyrene derivatives, polysiloxane, polyester, polyether, polyacrylate, aliphatic polycarbonate, polysulfone, polylactide, and blends thereof. The present compositions are particularly useful as dielectric substrate material in microchips, multichip modules, laminated circuit boards, and printed wiring boards.

The invention discloses a polylactide containing a side hydroxy or side carboxy functional group and a preparation method thereof. According to the preparation method, a polylactide with a functionalized norbornene-containing side group and a mercapto compound undergo mercapto-alkene click chemical reaction to form the polylactide containing the side hydroxy or side carboxy functional group. The preparation method for the polylactide is simple, quick and low in cost; a plurality of hydrophilic polar active groups are introduced to the main chain through norbornene, so that the prepared polylactide has multiple structures, high degradability, strong hydrophilic property and many active groups; and when the polylactide serving as a medicament carrier is applied to preparation of a pro-medicament, the prepared pro-medicament is high and controllable in medicament loading rate and good in hydrophilic property, can be completely degraded, contains groups capable of being modified again and has great scientific research and economic value.

A macromer based novel copolymer comprising an acrylate or methacrylate ester of low molecular weight oligomeric lactide copolymerized with basic monomer is provided. These copolymers show unusual dissolution behavior in that they are soluble over a wide range of pH from 1.8 to 7.4. This unexpected solubility behavior can be exploited to develop pharmaceutical dosage forms.

A nanosphere or microsphere drug carrier, formulations comprising the drug carrier and the preparation method of the formulations and the use of the carrier are disclosed. The carrier comprises a biodegradable methoxy end-capped polyethylene glycol-polylactide block copolymersor a derivative thereof represented by formula (I) as the main carrier material: CH3O—[CH2—CH2—O]m—[C(O)—CH(CH3)—O]n—R (I).

The invention discloses a degradable biological-based waterborne emulsion and a preparation method thereof. The preparation method comprises the following steps: carrying out a polymerization reaction on purified L-lactide, epsilon-caprolactone and polyol under the action of a catalyst, to obtain hydroxyl-terminated polyester polyol with the viscosity average molecular weight of 1000-10000; carrying out a reaction of hydroxyl-terminated polyester polyol, diisocyanate and a hydrophilic chain extender under the action of a catalyst, to obtain a prepolymer; and adding an emulsifier and water in the prepolymer, carrying out high-speed stirring emulsification, and carrying out a reaction with a crosslinking agent, to obtain the degradable waterborne emulsion. The degradable biological-based emulsion and the preparation method thereof are novel; the polylactide and caprolactone random copolymer which can be fully biodegradable is obtained, has relatively low glass transition temperature (Tg), has better emulsifying dispersion than polylactide, does not contain organic solvents, is biodegradable, can be widely applied in coatings, adhesives, fabric coating layers and other fields, is a quite good environmental-protection material, and has broad market prospects.

The invention provides a curcumin micelle drug delivery system, a preparation method thereof and application of the curcumin micelle drug delivery system in treating tumor diseases. The drug delivery system is prepared from, by mass, 80-99.9% of amphiphilic segmented copolymer and 0.1-20% of curcumin. The amphiphilic segmented copolymer comprises a hydrophilic chain segment and a hydrophobic chain segment, wherein polyethylene glycol with the molecular weight of 100-6000 or methoxy polyethylene glycol with the molecular weight of 300-6000 serves as the hydrophilic chain segment, polylactide with the molecular weight of 200-6000 serves as the hydrophobic chain segment, the hydrophobic chain segment is subjected to end capping through groups containing fmoc and / or amino acid containing benzene ring structures, and the weight ratio of polyethylene glycol or methoxy polyethylene glycol to polylactide is (0.1-30):1. The invention further provides application of the drug delivery system in preparing tumor treating drugs.

A nanoparticle that has a membrane including a polylactide-block-poly(ethylene glycol)-block-polylactide (PLA-PEG-PLA) and a polyvinyl alcohol, a bovine serum albumin contacting the membrane on the outside of the nanoparticle, a targeting group attached to the outside of the nanoparticle, and a breast cancer therapeutic agent that is encapsulated by the membrane. A nanoparticle that consists of a membrane including a polylactide-block-poly(ethylene glycol)-block-polylactide (PLA-PEG-PLA) and a polyvinyl alcohol, a bovine serum albumin contacting the membrane on the outside of the nanoparticle, breast cancer therapeutic agent that is encapsulated by the membrane, and an anti-Her2 antibody attached to the outer surface of the nanoparticle. A range of a number average molecular weight of the PEG block is 800 Da to 3 kDa and a range of a number average molecular weight of each of the PLA blocks is from 1 kDa to 5 kDa.

Novel absorbable polymeric blends made from components wherein at least one of the components is synthesized using mixtures of mono- and di-functional initiators are disclosed. The blends have a first component that is a polylactide polymer or a copolymer of lactide and glycolide and a second component that is either poly(p-dioxanone) homopolymer, or a poly(p-dioxanone-co-glycolide) copolymer. The novel polymeric blends provide medical devices having dimensional stability. Also disclosed are novel absorbable medical devices made from these novel polymer blends, as well as novel methods of manufacture.

Process for increasingly producing D-Lactide and meso lactide by depolymerizing by back biting polylactide (PLA) said process which comprises: (i) Depolymerizing polylactide into its corresponding dimeric cyclic esters by heating the polylactide in the presence of a catalyst system comprising a catalyst and a co-catalyst in a reaction zone at temperature and pressure at which the polylactide is molten; (ii) Forming a vapor product stream from the reaction zone; (iii) Removing the vapor product stream and optionally condense it; (iv) Recovering, either together or separately meso-lactide, D-lactide and L-lactide.

The present invention relates to preparation of biodegradable microparticles formed from polylactide-polyglycolide copolymers (PLGA) polymer and how to achieve sigmoidal release of active pharmaceutical compound from the microparticles. In particular, the present invention relates to emulsification of an inner / oil phase to an outer / water phase followed by quenching and a single drying step for the preparation of microparticles having a preferred release profile of preferably basic / nucleophilic compounds such as risperidone. Alternatively the present invention is also suitable for hydrophobic compounds that have poor water-solubility and a high drug loading of >20% w / w is required. The release profile can be controlled by adjusting the degree of saturation of the outer / water phase with the organic solvent used in the inner / oil phase, the polymer concentration of the inner / oil phase and the temperature at the quenching step. In particular, an initial lag phase and a substantially sigmoidal release profile are achieved by using an outer aqueous phase over saturated with the solvent used in the inner phase at emulsification step, in combination with a low temperature during quenching.