Continued Development of an Implantable Sustained Release System for the Prevention of Malaria.
Annual rept. 25 Mar 75-23 Mar 76,
DYNATECH R/D CO CAMBRIDGE MASS
Pagination or Media Count:
The release of S35-labelled WR-7557 from three candidate polymeric matrices has been measured in vitro and in vivo in mice. They are 116 in. diameter beads and 132 in. diameter rods of a 50 d1-lactic50 L-lactic acid copolymer containg 33.3 WR-7557 and a 90 to 180 micron cryogenically ground powder of a 100 poly L-lactic acid containing 20 WR-7557. The three materials released the drug very slowly, both in vitro and in vivo. A 90 to 180 micron powder has been ground from the 132 in. diameter rods to increase the surface area and in vitro and in vivo evaluation initiated. The release of WR-158122 has been measured from finely divided particles. Steady release of WR-158122 in vivo from a less than 44 micron spray dried powder of a 90 L-lactic10 glycolic acid copolymer containing 60 WR-158122 has been demonstrated with an extrapolated duration of release of over 500 days. The glycolate salt increased the solubility of WR-158122 significantly.