The effects of heat treatment time and temperature on the delivery behaviour of Ibuprofen from hydroxyapatite particles were investigated in this study. The drug release was seen to follow Fickian diffusion for the initial period of release for all heat treatment conditions. The gradient of Fickian release increased with (1) increasing crystallite size, attributed to the decreasing amount of boundary area, and (2) with decreasing surface area, due to the reduction in porosity and hence tortuosity within the apatite particles. This study has shown that altering the heat treatment conditions used to calcine hydroxyapatite may alter its drug delivery abilities, whereby calcination temperature was noted to influence the drug release behaviour to a greater extent than calcination time.