Patent ID: 6927210

Claim:
A stable ectoparasiticidal aqueous suspension formulation suitable for administration to animals comprising: a) an ectoparasiticidal amount of spinosad, milled to an average particle size of from 1 to 15 microns; b) a condensed formaldehyde/naphthalene sulfonic acid or salt thereof dispersant, wherein the spinosad:dispersant weight ratio is 3:1 to 1:5; c) 0.3 to 5 weight percent of a mineral thickener; d) an antimicrobial agent acceptable for topical veterinary applications in an amount effective to prevent microbial growth in the suspension; e) propylene glycol; f) 0.05 to 3 weight percent of xanthan gum; g) 0.1 to 10 weight percent of at least one surfactant; h) an antifoam agent; and i) water; wherein said formulation is chemically and physically stable.