In situ preparation of a laminated hydroxyapatite/ methotrexate complex

In this study, for the first time, a laminated hydroxyapatite (HAp)/ methotrexate (MTX) complex was synthesized by in situ method using polyethylene glycol (PEG, MW8000) as template. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and UV-vis spectrophotometer were used to investigate the morphology, interaction and drug release property of synthesized HAp/MTX complex. SEM investigation indicated that laminated HAp/MTX complex with size ranging of 150-200 nm was obtained in the present of PEG molecules. The interaction between COO− of MTX and Ca2+ of HAp was confirmed by FTIR investigation. In vitro drug release test indicated that the complex exhibits slow drug release ability which attributed to the laminated structure and interaction between MTX and HAp. Furthermore, it is confirmed that the drug release kinetic fitted Rigter-Pappas-order equation best which indicated that the drug release mechanism is a combination of MTX diffusion and HAp/MTX complex dissolution.