Purpose: To prepare solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) of loratadine (LRT) for the treatment of allergic skin reactions.
Abstract
Purpose: To prepare solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) of
loratadine (LRT) for the treatment of allergic skin reactions.
Methods: SLN and NLC were prepared by high pressure homogenization method. Their entrapment
efficiency (EE) and loading capacity (LC) were determined. The physical stability of nanoparticles was
investigated during 6 months of storage at room temperature (RT), 4 and 40 oC. Fourier transform
infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and laser diffraction (LD) were
used for the investigation of drug:excipient compatibility, thermal behaviour and particle size of the
nanoparticles. In vitro release and ex vivo skin penetration of LRT were studied. Nanoemulsions (NE)
were also prepared and characterized for comparison.
Results: Nanoparticles sizes ranged from 0.222 ± 0.011 μm to 0.252 ± 0.014 μm (D50 as a value based
on the volume distribution, the maximum particle diameter below which 50 % of the sample volume
exists) They were obtained with high drug payloads (> 90.67 %). LRT was compatible with the other
excipients after 6 months. Particle size did not significantly alter particularly at RT. The highest release
rate was obtained with NE (1.339 ± 0.026 mcg/ml/h) followed by NLC (1.007 ± 0.011 mcg/ml/h) and
SLN (0.821 ± 0.012 mcg/ml/h), indicating anomalous transport (p < 0.05). Penetration profiles of LRT
through skin were statistically similar for SLN and NLC (p > 0.05). NE showed the highest penetration
rate (0.829 ± 0.06 mcg/cm2/h) (p < 0.05).
Conclusion: SLN and NLC of LRT are alternative formulations for immediate treatment of allergic skin
reactions with prolonged drug delivery via reservoir action.
