Long-term delivery of ivermectin by use of poly(D,L-lactic-co-glycolic)acid microparticles in dogs.

Objective: To evaluate the potential utility of poly(D,L-lactic-co-glycolic)acid (PLGA) as a long-acting biodegradable drug delivery matrix for ivermectin used in the prevention of heartworm disease in dogs.

Animals: 30 adult female dogs.

Procedure: Microparticle formulations containing 25 weight percent (wt%), 35 wt%, and 50 wt% ivermectin were prepared by an oil-in-water emulsion technique with solvent extraction into excess water.