We used the possibility of α-tricalcium phosphate (α-TCP) particles incorporated with carboplatin (CBDCA) as a drug carrier using a rat experimental model of AH-130 abdominal carcinomatosis. α-TCP is known to have excellent biocompatibility and biodegradable and its chemical properties are similar to hydroxyapatite. The α-TCP paticles used in this study was 50-150 μm in diameter, which seemed to offer adequate space to incorporate drug. We studied the biodegradation behavior of the particles in the abdominal cavity and the distribution kinetics of platinum (Pt) in serum, ascites, and various organs following ip administration. The α-TCP paticles were predominantly taken up in the milky spot of greater omentum in a few days, and dissolved gradually in six months, during which no adhesion and side effects were observed. The Pt levels in ascites and the greater omentum were higher in the α-TCP-CBDCA ip group from 0.5 to 168 hours than those in the free-CBDCA ip and iv groups. The Pt levels in serum were almost the same both in the α-TCP-CBDCA ip and the free-CBDCA ip, but those in organs were lower in the α-TCP-CBDCA ip. These results suggest that the localization of CBDCA may be enhanced by using porous α-TCP particles as a drug delivery carrier and may be allow for the drug to contact with cancer cells for extended times.
