Sustained release of adriamycin from implanted hydroxyapatite blocks for the treatment of experimental osteogenic sarcoma in mice.

A sustained-release drug delivery system was developed using a hydroxyapatite (HA) block loaded with adriamycin (ADR) by cenrifugation. Release of ADR was sustained for 66 days in vitro and for 4 weeks in vivo following intramuscular implantation in mice. ADR concentrations in plasma, liver, and kidney were from 0.25% to 10% of that at the implantation site. ADR-HA blocks implanted into osteogenic sarcomas in mice markedly inhibited tumor growth. This drug delivery system provides sustained release of the cancer chemotherapeutic agent and may prove useful for treating malignant tumours while minimising systemic side effects.