Abstract: 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.

Abstract: Drug-containing nanoparticles are provided that enable effective targeting and sustained-release of a water-soluble, non-peptide, low-molecular weight drug and cause reduced accumulation of the drug in the liver. The nanoparticles containing a water-soluble, non-peptide, low-molecular weight drug are obtained by hydrophobicizing the water-soluble, non-peptide, low-molecular weight drug by a metal ion, and reacting the hydrophobicized drug with a poly(lactic acid)-polyethylene glycol block copolymer or a poly(lactic-co-glycolic acid)-polyethylene glycol block copolymer. The nanoparticles have favorable targeting and sustained-release properties and cause reduced accumulation of the drug in the liver.

Abstract: 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.

Abstract: A nanoparticle containing a low-molecular-weight drug having a negatively charged group is provided that is effectively targeted to an affected site, is capable of sufficiently sustained release of the drug, and has a reduced tendency to accumulate in the liver to cause reduced side effects. The nanoparticle containing a low-molecular-weight drug having a negatively charged group is obtained by hydrophobicizing the low-molecular-weight drug having a negatively charged group with a metal ion, and reacting the hydrophobicized drug with poly L-lactic acid or poly(L-lactic acid/glycolic acid) copolymer and poly DL- or L-lactic acid-polyethylene glycol block copolymer or poly(DL- or L-lactic acid/glycolic acid)-polyethylene glycol block copolymer.

Abstract: Drug-containing nanoparticles are provided that enable effective targeting and sustained-release of a water-soluble, non-peptide, low-molecular weight drug and cause reduced accumulation of the drug in the liver. The nanoparticles containing a water-soluble, non-peptide, low-molecular weight drug are obtained by hydrophobicizing the water-soluble, non-peptide, low-molecular weight drug by a metal ion, and reacting the hydrophobicized drug with a poly(lactic acid)-polyethylene glycol block copolymer or a poly(lactic-co-glycolic acid)-polyethylene glycol block copolymer. The nanoparticles have favorable targeting and sustained-release properties and cause reduced accumulation of the drug in the liver.

Abstract: To provide an external preparation or injectable preparation that exerts the effect of enabling transdermal or transmucosal in viva absorption of fat-soluble drugs and water-soluble drugs not having been satisfactorily attained hitherto and that contains a highly absorbable fat-soluble/water-soluble drug, the injectable preparation especially aiming at sustained-release and target effects. In particular, drug-containing nanoparticles (secondary nanoparticles) are provided by causing primary nanoparticles containing a fat-soluble drug or fat-solubilized water-soluble drug to act with a bivalent or trivalent metal salt. Further, drug-containing nanoparticles (tertiary nanoparticles) are provided by first causing primary nanoparticles containing a fat-soluble drug or fat-solubilized water-soluble drug to act with a bivalent or trivalent metal salt to thereby obtain secondary nanoparticles and thereafter causing a monovalent to trivalent basic salt to act on the secondary nanoparticles.

Abstract: Provided are poly(lactic-co-glycolic acid) (PLGA) and poly(lactic acid) (PLA) nanoparticles that encapsulate a low molecular weight and water-soluble drug and can deliver the drug to target legion sites where the particles gradually release the drug over a prolonged period of time. The nanoparticles are prepared by allowing the low-molecular, water-soluble and non-peptide drug to interact with a metal ion so as to make the drug hydrophobic, encapsulating the hydrophobicized drug into PLGA or PLA nanoparticles, and allowing a surfactant to be adsorbed onto the surface of the particles.

Abstract: A composition for intravenous injection, which gradually decomposed instead of fat particles, has sufficient sustained release effects, has an excellent encapsulation ratio of lipid-soluble agents, and has such sustained release effects at lesion sites; a production method thereof; and a preparation containing the composition. The composition for intravenous injection is produced by encapsulating a prostanoid or steroid in a poly(lactic-co-glycolic acid) or poly(lactic acid) microparticle, and allowing lecithin or similar surfactant to be adsorbed on the surface or the above poly(lactic-co-glycolic acid) or poly(lactic acid) microparticle.

Abstract: A delay circuit for delaying a digital input signal has a ramp generator, a logic circuit which provides a delayed output when the ramp voltage reaches threshold voltage, and a bias circuit which provides bias voltage to the ramp generator so that the delayed output is free from temperature variation, power supply voltage variation and process variation of semiconductor elements.

Abstract: A signal conversion circuit converts variations in resistance into an electrical signal. The conversion circuit comprises both a bridge circuit and a single operational amplifier with a capacitor between them to store voltage samples produced by an unbalancing of the bridge. The bridge circuit has a detector element such as a strain gauge for providing a resistance variation. A capacitor is connected through switches to both the bridge circuit and signal operational amplifier. The switches operate in a sequence whereby the operational amplifier is disconnected from the capacitor during the storage of the sample and the bridge is disconnected from the capacitor during intervals while the charged capacitor is connected to the amplifer.

Abstract: An electronic circuit uses a two input operational amplifier for converting a pressure into an electrical signal. The bias potentials at the two inputs are equal to each other in the absence of pressure. The bias potential is applied to one input via a pressure sensitive resistor comprising a semiconductor diaphram with a resistance diffused thereon. When pressure appears, the resistance changes and there is a difference of potential at the two inputs, which is processed into the electrical signal.