34 results about "Drugs retention" patented technology

Methods and apparatus are disclosed for loading a therapeutic substance or drug within a lumenal space of a hollow wire having a plurality of side openings along a length thereof that forms a hollow drug-eluting stent with a plurality of side drug delivery openings. Loading a drug within the lumenal space of the hollow stent includes a drug filling step, in which the drug is mixed with a solvent or dispersion medium. The lumenal space may be filled with the drug solution or suspension in a reverse fill process and / or a forward fill process. After the drug filling step, a solvent or dispersion medium extracting step is performed to extract the solvent or dispersion medium from within the lumenal space such that only the drug remains within the hollow stent. A stent cleaning step may be performed to an exterior surface of the hollow stent.

The present invention provides liposome compositions containing sparingly soluble drugs that are used to treat life-threatening diseases. A preferred method of encapsulating a drug inside a liposome is by remote or active loading. Remote loading of a drug into liposomes containing a transmembrane electrochemical gradient is initiated by co-mixing a liposome suspension with a solution of drug, whereby the neutral form of the compound freely enters the liposome and becomes electrostatically charged thereby preventing the reverse transfer out of the liposome. There is a continuous build-up of compound within the liposome interior until the electrochemical gradient is dissipated or all the drug is encapsulated in the liposome. However, this process as described in the literature has been limited to drugs that are freely soluble in aqueous solution or solubilized as a water-soluble complex. This invention describes compositions and methods for remote loading drugs with low water solubility (<2 mg / mL). In the preferred embodiment the drug in the solubilizing agent is mixed with the liposomes in aqueous suspension so that the concentration of solubilizing agent is lowered to below its capacity to completely solubilize the drug. This results in the drug precipitating but remote loading capability is retained. The process is scalable and, in liposomes in which the lipid composition and remote loading agent are optimized, the resulting drug-loaded liposomes are characterized by a high drug-to-lipid ratios and prolonged drug retention when the liposome encapsulated drug is administered to a subject.

There is provided a beraprost sodium-containing nanoparticle that contains beraprost sodium among other prostaglandin I2 (prostacyclin) derivatives, which are therapeutic agents for pulmonary hypertension. The beraprost sodium-containing nanoparticle is obtained by making beraprost sodium hydrophobic using a metal ion and allowing the hydrophobic beraprost sodium to react with poly-L-lactic acid or a poly(L-lactic acid / glycolic acid) copolymer, and a poly-DL- or L-lactic acid-polyethylene glycol block copolymer or a poly(DL- or L-lactic acid / glycolic acid)-polyethylene glycol block copolymer. The beraprost sodium-containing nanoparticle excels in sustained release of an active ingredient, reduces a side effect, and furthermore, has an excellent drug retention in the blood. Therefore, the beraprost sodium-containing nanoparticle is quite outstanding particularly regarding the sustainability of the medicinal effect.

The invention describes a liposome composition for enhanced retention of a quinolone compound, and in particular of a fluoroquinolone compound. Entrapped in the liposomes is a polyanionic polymer effective to form a complex with the fluoroquinolone. A method of preparing the liposomes which includes a process for removal of unentrapped polyanionic polymer is also described.

The present invention provides an amphiphilic block copolymer for drug delivery and a controlled release system comprising the same copolymer. The copolymer comprises at least one hydrophilic block and at least one hydrophobic block, wherein the hydrophobic block is selected from the group consisting of acrylates, methacrylates, acrylamides, methacrylamides, vinylethers and their aromatic derivatives, wherein at least one hydrophobic block contains an aryl group, which is bound to the hydrophobic block with a degradable linker. The controlled release system of the invention shows high stability and high drug retention when administered in vivo enabling accumulation and drug release at the site of action.