{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T11:16:26Z","timestamp":1789902986628,"version":"4.0.1"},"reference-count":17,"publisher":"American Veterinary Medical Association (AVMA)","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ajvr"],"published-print":{"date-parts":[[2004,6,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n\t\t\t\t<jats:p>\n\t\t\t\t\t<jats:bold>Objective<\/jats:bold>\u2014To evaluate the potential utility of\npoly(D,L-lactic-co-glycolic)acid (PLGA) as a long-acting\nbiodegradable drug delivery matrix for ivermectin\nused in the prevention of heartworm disease in dogs.<\/jats:p>\n\t\t\t\t<jats:p>\n\t\t\t\t\t<jats:bold>Animals<\/jats:bold>\u201430 adult female dogs.<\/jats:p>\n\t\t\t\t<jats:p>\n\t\t\t\t\t<jats:bold>Procedure<\/jats:bold>\u2014Microparticle formulations containing 25\nweight percent (wt%), 35 wt%, and 50 wt% ivermectin\nwere prepared by an oil-in-water emulsion\ntechnique with solvent extraction into excess water. A\nfourth formulation, consisting of a mixture of 15 wt%\nand 50 wt% ivermectin microparticles, was blended\nin a 1:1 ratio to result in a 32.5 wt% ivermectin formulation.\nFormulations were administered once on\nDay 0 to groups of 6 dogs at a dose of 0.5 mg of ivermectin\/\nkg, SC. Half of the dogs in each treatment\ngroup and 3 untreated control dogs were infected\nwith <jats:italic>Dirofilaria immitis<\/jats:italic> larvae 121 and 170 days after\ntreatment. Six months after infection, dogs were\neuthanatized and necropsies were performed.\nPharmacokinetics and efficacy were investigated.<\/jats:p>\n\t\t\t\t<jats:p>\n\t\t\t\t\t<jats:bold>Results<\/jats:bold>\u2014Analysis of pharmacokinetic data revealed\nsustained release of ivermectin during at least 287\ndays in 3 distinct phases: a small initial peak, followed\nby release of drug through diffusion, and polymer\ndegradation. Untreated control dogs were all infected\nwith heartworms. Heartworms were not found in any\nof the dogs in the ivermectin-PLGA treated groups.\nAdverse clinical signs were not observed.<\/jats:p>\n\t\t\t\t<jats:p>\n\t\t\t\t\t<jats:bold>Conclusions and Clinical Relevance<\/jats:bold>\u2014All formulations\nwere 100% effective in preventing development\nof adult heartworms. Results indicate that PLGA\nmicroparticles are a promising drug delivery matrix for\nuse with ivermectin for the prevention of heartworm\ndisease for at least 6 months after treatment. (<jats:italic>Am J\nVet Res<\/jats:italic> 2004;65:752\u2013757)<\/jats:p>","DOI":"10.2460\/ajvr.2004.65.752","type":"journal-article","created":{"date-parts":[[2006,1,23]],"date-time":"2006-01-23T18:32:19Z","timestamp":1138041139000},"page":"752-757","source":"Crossref","is-referenced-by-count":31,"title":["Long-term delivery of ivermectin by use of poly(D,L-lactic-co-glycolic)acid microparticles in dogs"],"prefix":"10.2460","volume":"65","author":[{"given":"Steven L.","family":"Clark","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angela J.","family":"Crowley","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul G.","family":"Schmidt","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ann R.","family":"Donoghue","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claude A.","family":"Pich\u00e9","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1272","reference":[{"key":"p_1_168","first-page":"48","volume":"2","author":"Campbell WC","year":"1984","journal-title":"Semin Vet Med Surg (Small Anim)"},{"key":"p_2_169","doi-asserted-by":"crossref","first-page":"517","DOI":"10.2460\/ajvr.1991.53.04.517","volume":"53","author":"Clark JN","year":"1992","journal-title":"Am J Vet Res"},{"key":"p_3_170","doi-asserted-by":"publisher","DOI":"10.1016\/S0304-4017(00)00297-1"},{"key":"p_4_171","first-page":"139","volume":"43","author":"Genchi C","year":"2001","journal-title":"Parassitologia"},{"key":"p_5_172","first-page":"115","author":"Bradley R","year":"1989","journal-title":"Ill: American Heartworm Society"},{"key":"p_6_173","first-page":"149","author":"Lok JB","year":"2001","journal-title":"Ill: American Heartworm Society"},{"key":"p_7_174","first-page":"1","author":"Lewis DH","year":"1990","journal-title":"New York: Marcel Dekker Inc"},{"key":"p_8_175","first-page":"77","author":"Lewis DH","year":"1983","journal-title":"Philadelphia: Harper & Row"},{"key":"p_9_176","doi-asserted-by":"publisher","DOI":"10.1095\/biolreprod28.1.186"},{"key":"p_10_177","doi-asserted-by":"crossref","first-page":"1142","DOI":"10.1093\/jee\/92.5.1142","volume":"92","author":"Miller JA","year":"1999","journal-title":"J Econ Entomol"},{"key":"p_11_178","doi-asserted-by":"publisher","DOI":"10.1039\/an9962101533"},{"key":"p_12_179","unstructured":"FDA. 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