Biodegradability of naltrexone-poly(DL) lactide implants in vivo assessed under ultrasound in humans.

Ultrasound was used to assess the in vivo biodegradability of a sustained release poly(DL)lactide naltrexone implant in 71 persons previously treated for heroin dependence. We assessed 139 implant sites ranging from 2 to 1808 days post implant. Ultrasound assessment showed that implant tablets were initially well demarcated from each other and from the surrounding tissues.