Physicochemical characteristics and in vitro permeation of loratadine solid lipid nanoparticles for transdermal delivery.

Aim: To prepare loratadine-loaded solid lipid nanoparticles (SLNs) using a modified two-step ultrasound-assisted phase inversion temperature (PIT) process. Results/methodology: Loratadine was dissolved in beeswax and Tween 80 was dissolved in water. The two phases were mixed together to prepare a water-in-oil emulsion preconcentrate (w/o) at a PIT of 85°C, followed by gradual water addition at 25°C to trigger nanoparticles formation (o/w). Kinetic stability was investigated. No change in the size was observed within 6 months. Fourier-transform infrared spectroscopy demonstrated stability of the emulsions via molecular structure of water at the interface of the o/w nanoemulsions. SLNs enhanced the in vitro skin permeation of loratadine. Conclusion: Stable SLNs were successfully prepared by ultrasound-assisted PIT.