Methods and compositions for producing a cellular drug release are disclosed. The method comprises: a) providing a composition comprising a therapeutically effective amount of a pharmacological agent adsorbed onto mesoporous hydroxyapatite (HAP) with hydrophobic surfaces b) exposing the composition to a cell c) causing entry of the mesoporous HAP into the cell and degradation of the HAP in the lysosomes of the cell and desorption of the agent from the mesoporous HAP d) causing release of the desorbed agent from the lysosomes into the cytoplasm of the cell and e) causing release of the desorbed agent to outside the cell. The composition comprises a) mesoporous HAP with hydrophobic surfaces and b) a therapeutically effective amount of a pharmacological agent, adsorbed onto the hydrophobic surfaces of the mesoporous. HAP. The composition is characterized in that it constantly releases the agent in vivo for a period of at least 4 weeks.
