10.1021/acs.jmedchem.5b00714.s002 Yan-Jye Shyong Yan-Jye Shyong Mao-Hsien Wang Mao-Hsien Wang Hsiang-Chien Tseng Hsiang-Chien Tseng Chen Cheng Chen Cheng Kuo-Chi Chang Kuo-Chi Chang Feng-Huei Lin Feng-Huei Lin Mesoporous Hydroxyapatite as Olanzapine Carrier Provides a Long-Acting Effect in Antidepression Treatment American Chemical Society 2015 medication release calcium ion coprecipitation method extracellular space nonadherent medication intake Mesoporous Hydroxyapatite mesoHAP Olanzapine Carrier Provides Mesoporous hydroxyapatite blood circulation OLZ 2 weeks drug release treatment strategy IM surface modifications antidepressant therapy Antidepression TreatmentAn antidepressant carrier 2015-11-12 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Mesoporous_Hydroxyapatite_as_Olanzapine_Carrier_Provides_a_Long_Acting_Effect_in_Antidepression_Treatment/2109172 An antidepressant carrier was designed to maintain over 2 weeks of constant medication release. The carrier was injected into muscle, where cellular activity was employed to achieve the goal of constant release. Mesoporous hydroxyapatite (mesoHAP) was synthesized into an adequate size by a coprecipitation method; it then went through a series of hydrophobic surface modifications for olanzapine (OLZ) loading by physical absorption to produce mesoHAP–OLZ. Because of its hydrophobic nature, OLZ was not effectively released from mesoHAP–OLZ in an aqueous environment. However, once engulfed by macrophages, the lysosome/endosome hybrid ruptured due to alterations in osmotic pressure, resulting in the release of OLZ into the cytoplasm. OLZ was then exocytosed to the extracellular space due to a high calcium ion (Ca<sup>2+</sup>) concentration and finally reached the blood circulation. Our findings provide a useful treatment strategy to achieve long-term drug release with a single intramuscular (IM) injection, helping to solve the problem of nonadherent medication intake that often occurs in antidepressant therapy.