Lymphotropic and sustained delivery of aclarubicin from lactic acid-oligomer microspheres

—Effect of molecular weight of lactic acid-oligomer and of size of microspheres—

Abstract

The in vitro release of aclarubicin (ACR) from the microspheres (MS) and the lymphotropic delivery of ACR were studied using a different molecular weight of lactic acid-oligomers and a different size of microspheres (MS). The more sustained release of ACR was observed with an increase of molecular weight of lactic acid-oligomers, while a size of MS did not so influence. The pronounced delivery into lymph nodes was observed after intramuscular injection of ACR-MS but not after subcutaneous injection. The ACR-MS with small size was effectively targeted to lymph nodes, where ACR was prolonged retained. The largest molecular weight, 10, 000, and small size of MS showed the most effective lymph targeting and longest retention in the regional lymph node.