title: Preparation of microcapsules containing rare-earth metal elements.
abstract: Microcapsules for internal radiation therapies containing the rare-earth metal elements Dy, Ho and Cu with a diameter of 5-10 microm were successfully obtained by an interfacial polymerization method and a successive sedimentation technique was employed to fractionate the microcapsules. A triisocyanate monomer and tricresylphosphate were used for a wall forming material and a core solvent for the metals, respectively. The amount of the metal elements loaded was measured using a high frequency plasma photoemission apparatus. The beta-ray radioactivity of 1 mg of microcapsules irradiated with a common neutron source is estimated as 370 microCi, which is satisfactorily strong for usual radiotherapy, when microcapsules containing Dy are used. Differential interference microscopy indicated narrow size distribution of the fractionated microcapulses.
authors.affiliation: Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shimofure
authors.forename: S
authors.initials: S
authors.lastname: Koizumi
authors.forename: K
authors.initials: K
authors.lastname: Ichikawa
authors.forename: H
authors.initials: H
authors.lastname: Ichikawa
authors.forename: T
authors.initials: T
authors.lastname: Dobashi
mesh_terms: D000465:Algorithms; D002214:Capsules; D002499:Centrifugation, Density Gradient; D002614:Chelating Agents; D003300:Copper / Q000008:administration & dosage; D004339:Drug Compounding / Q000379:methods*; D004419:Dysprosium / Q000008:administration & dosage; D006695:Holmium / Q000008:administration & dosage; D008567:Membranes, Artificial; D008674:Metals, Rare Earth / Q000008:administration & dosage*; D011108:Polymers; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D014520:Urethane
chemical_list: D002214:Capsules; D002614:Chelating Agents; D008567:Membranes, Artificial; D008674:Metals, Rare Earth; D011108:Polymers; D019275:Radiopharmaceuticals; D004419:Dysprosium; C045786:polyurea; D014520:Urethane; D003300:Copper; D006695:Holmium