9B-5 Ultrasound Therapy with Drug Loaded Microcapsules

A novel class of acoustically active microcapsules that partially contain drug-bearing oil with gas offers great potential for localized drug release. The acoustical activation threshold and rate of such microcapsules with different oil-to-gas ratios were measured in vitro. Drug loaded microcapsules were prepared from which the anti-cancer drug paclitaxel was delivered in murine tumors. For recovered mice each with two tumors on the left and right hind legs, the growth rate of the acoustically treated tumors was substantially reduced in comparison to that of the untreated tumor on the same mouse. These initial results showed that lipophilic drugs can be packaged in microcapsules and released locally using focused ultrasound.