Sustained release of simvastatin from hollow carbonated hydroxyapatite microspheres prepared by aspartic acid and sodium dodecyl sulfate

- Hollow hydroxyapatite (HHAp) microspheres were synthesized in a novel method.
- The HHAp microspheres were constructed by short needle nanoparticles.
- The HHAp microspheres could be used as simvastatin sustained-release vehicles.
- The HHAp exhibited superior drug-loading capacity and sustained release properties.

Hollow carbonated hydroxyapatite (HCHAp) microspheres as simvastatin (SV) sustained-release vehicles were fabricated through a novel and simple one-step biomimetic strategy. Firstly, hollow CaCO3 microspheres were precipitated through the reaction of CaCl2 with Na2CO3 in the presence of aspartic acid and sodium dodecyl sulfate. Then, the as-prepared hollow CaCO3 microspheres were transformed into HCHAp microspheres with a controlled anion-exchange method. The HCHAp microspheres were 3-5 μm with a shell thickness of 0.5-1 μm and were constructed of short needle nanoparticles. The HCHAp microspheres were then loaded with SV, exhibiting excellent drug-loading capacity and sustained release properties. These results present a new material synthesis strategy for HCHAp microspheres and suggest that the as-prepared HCHAp microspheres are promising for applications in drug delivery.

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