A method for co-precipitating a therapeutic agent into a hydroxyapatite coated surface includes the steps of providing a surface and applying a hydroxyapatite seed layer on the surface. The hydroxyapatite seed layered surface is contacted with a solution including the therapeutic agent and a co-precipitated therapeutic agent, hydroxyapatite layer is formed on the coated surface to uniformly distribute the therapeutic agent in the layer. Further, an implant having sustained therapeutic agent delivery includes a base and an hydroxyapatite seed layer disposed on a surface of the base. A co-precipitated hydroxyapatite coating is disposed on the seed layer. The coating includes a therapeutic agent, wherein the therapeutic agent is provided in a solution of therapeutic agent.
