Accession Number : ADA017503

Title :   Continued Development of an Implantable Sustained Release System for the Prevention of Malaria.

Descriptive Note : Annual rept. 24 Jun 74-24 Mar 75,


Personal Author(s) : Gregory,John B. ; Wise,Donald L.

Report Date : 15 APR 1975

Pagination or Media Count : 61

Abstract : 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: 1/16-in. diameter beads of a 50% L(+)-lactic/50% 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 1/16-in. diameter beads of a 90% L(+)-lactic/10% 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(+)-lactic/10% 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)

Descriptors :   *Antimalarials, Implantation, Beads, Sulfadiazine, Mice, In vivo analysis, Release, Dose rate, Long range(Time), In vitro analysis, Solubility, Lactic acid, Copolymers, Glycolic acid, Powders, Citric acid, Salts, Injections(Medicine)

Subject Categories : Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE