Solid Lipid Nanoparticles and Nanostructured Lipid Carriers of Loratadine for Topical Application: Physicochemical Stability and Drug Penetration through Rat Skin

M Üner,Ef Karaman,Z Aydoğmuş

doi:10.4314/tjpr.v13i5.1

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 o C. 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). NE showed the highest penetration rate (0.829 ± 0.06 mcg/cm 2 /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. Keywords : Loratadine, Transdermal delivery, Controlled drug delivery, Solid Lipid nanoparticles, Nanostructured lipid carriers, Allergy

Highlights

Histamine which is present as a tissue hormone, especially in the skin and lungs in human, is found in the bee poison and the salivary secretion of biting insects [1,2]
EE of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) was found as 90.67 ± 0.48 and 93.27 ± 0.44 % when loading capacity (LC) values were obtained as 6.06 ± 0.03 and 6.22 ± 0.03 %, respectively
Reduction in CI of placebo NLC (PNLC) and NLC compared to placebo SLN (PSLN) and SLN could be attributed to the crystal order in PNLC and NLC greatly disturbed due to the oil inside the particles

Summary

Introduction

Histamine which is present as a tissue hormone, especially in the skin and lungs in human, is found in the bee poison and the salivary secretion of biting insects [1,2]. When allergic skin reactions occur or immediately after being bitten by an insect, excess histamine is released causing itching and formation of skin weals and flares. LRT displays various side effects including several allergic reactions including rash, hives, itching, difficulty in breathing, tightness in the chest, swelling of the mouth or face and dizziness during systemic administration by oral route. LRT has a poor penetration through the skin This limitation may be overcome by incorporation of LRT into colloidal drug carrier systems like solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) [4,5]

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