Binary blend of glyceryl monooleate and glyceryl monostearate for magnetically induced thermo-responsive local drug delivery system.

PURPOSE: To develop a novel monoglycerides-based thermal-sensitive drug delivery system, specifically for local intracavitary chemotherapy.

METHODS

Lipid matrices containing mixtures of glyceryl monooleate (GMO) and glyceryl monostearate (GMS) were evaluated for their potential application as magnetically induced thermo-responsive local drug delivery systems using a poorly water-soluble model drug, nifedipine (NF). Oleic acid-modified iron oxide (OA-Fe3O4) nanoparticles were embedded into the GMO-GMS matrix for remote activation of the drug release using an alternating magnetic field (AMF).

RESULTS

The crystallization behavior of binary blends of GMO and GMS as characterized by DSC did show temperature dependent phase transition. GMO-GMS (75:25 wt%) blend showed a melting (T m ) and crystallization (T c ) points at 42°C and 37°C, respectively indicating the potential of the matrix to act as an 'on-demand' drug release. The matrix released only 35% of the loaded drug slowly in 10 days at 37°C whereas 96% release was obtained at 42°C. A concentration of 0.5% OA-Fe3O4 heated the matrix to 42.3 and 45.5°C within 5 min and 10 min of AMF exposure, respectively.

CONCLUSIONS

The in vitro NF release profiles form the monoglycerides matrix containing 0.5% OA-Fe3O4 nanoparticles after AMF activation confirmed the thermo-responsive nature of the matrix that could provide pulsatile drug release 'on-demand'.