In vitro sustained release of amoxicillin from lanthanum hydroxyapatite nano rods

Nano rods (∼100 nm) of pure hydroxyapatite [Ca10(PO4)6(OH)2)-HAp] and lanthanum doped HAp was synthesized by sol-gel route using calcium nitrate and diammonium hydrogen phosphate as precursors. The samples were without La2O3 or β-TCP phases, which were present in samples prepared by solid state and co-precipitation technique. Increase in the concentration of lanthanum lead to the enhancement of crystallinity and crystallite size. In addition, increase in specific surface area (31%) and hardness (14%) was observed in doped samples. The studies using PBS revealed a decrease in the dissolution of the samples as the dopant concentration increased. Further, the doping extended the amoxicillin release from the samples. Bactericidal effect against Gram positive and Gram negative bacteria indicated high antimicrobial resistant activity of these samples.

► Nano rods of pure and lanthanum doped hydroxyapatite synthesized without La2O3 or β–TCP phases.
► Enhanced crystallinity, crystallite size, hardness, surface area on La3+ doping.
► Exhibits controlled and extended drug release on doping.
► Decreased dissolution rate making it suitable for prevention of dental carries.
► Doping showed high resistance to Gram positive and Gram negative bacteria.