Continued Development of an Implantable Sustained Release System for the Prevention of Malaria.
Annual rept. 24 Jun 74-24 Mar 75,
DYNATECH R/D CO CAMBRIDGE MASS
Pagination or Media Count:
Uniform, sustained release of WR-7557 has been achieved in vitro. The effects of polymer type, molecular weight, drug content, and implant shape on the rate of WR-7557 in vitro release have been evaluated. Two 3-month WR-7557 systems have emerged 116-in. diameter beads of a 50 L-lactic50 dl-lactic acid copolymer containing 33 WR-7557, and a 144-177 micrometer powder of a 100 poly-L-lactic acid containing 20 WR-7557. In vivo evaluation in mice of 116-in. diameter beads of a 90 L-lactic10 glycolic acid copolymer containing 10 WR-7557 has demonstrated drug release too slow for a 3-month system. Steady release of WR-158122 from a less than 44 micrometer spray dried powder of a 90 L-lactic10 glycolic acid copolymer containing 60 WR-158122 has also been achieved in vitro and in vivo, but at a rate much too slow for a 3-month system. In vitro experiments with glycolic, lactic, and citric acid salts of WR-158122 have shown substantial increases in the release rate of this drug. Author