Dynamic compaction: a new process to compact therapeutic agent-loaded calcium phosphates.

The sintering stage in the classical process of preparing bone substitution materials prevents therapeutic agents from being loaded into calcium phosphate powder. However, dynamic compaction, a new process, requires no external heat, allowing the therapeutic agent to be incorporated into ceramics. This report presents the results of an in vitro study of therapeutic agents associated with calcium phosphate powder and involving this new process. A mixture of vancomycin lyophilized powder (0.15 g) and biphasic calcium phosphate (BCP) powder (1.85 g) was compacted. In addition, 2 ml of human growth hormone (1 mg ml-1) were associated with BCP powder by physical adsorption on bead surfaces before compaction. Detection by monoclonal antibodies and sodium dodecyl sulphate polyacrylamide gel electrophoresis demonstrated the structural integrity of the two therapeutic agents after consolidation. This new compaction process should be useful in developing ceramics that contain a therapeutic agent.