Evaluation of Drug-Loading Ability of Poly(Lactic Acid)/Hydroxyapatite Core-Shell Particles

Poly(lactic acid)/hydroxyapatite (PLA/HAp) core-shell particles are prepared using the emulsification method. These particles are safe for living organisms because they are composed of biodegradable polymers and biocompatible ceramics. These particles are approximately 50-100 nm in size, and their hydrophobic substance loading can be controlled. Hence, PLA/HAp core-shell particles are expected to be used as drug delivery carriers for hydrophobic drugs. In this work, PLA/HAp core-shell particles with a loading of vitamin K₁ were prepared, and their drug-loading ability was evaluated. The particles were 40-80 nm in diameter with a PLA core and a HAp shell. The particle size increased with an increase in the vitamin K₁ loading. The drug-loading capacity (LC) value of the particles, an indicator of their drug-loading ability, was approximately 250%, which is higher than the previously reported values. The amount of vitamin K₁ released from the particles increased as the pH of the soaking solution decreased because the HAp shell easily dissolved under the acidic conditions. The PLA/HAp particles prepared in this work were found to be promising candidates for drug delivery carriers because of their excellent drug-loading ability and pH sensitivity.