Preparation, characterization and evaluation of moisturizing and UV protecting effects of topical solid lipid nanoparticles

Abstract

Solid lipid nanoparticles (SLN) were recently proposed as carriers for various pharmaceutical and cosmetic actives. These lipid nanoparticles can act as moisturizers and physical sunscreens on their own. Therefore, the full potential of these carriers has yet to be determined. The present study was aimed to determine and compare moisturizing and UV-protecting effects of different solid lipid nanoparticles (SLN) prepared by different solid lipids including Glyceryl monostearate (GMS), Precirol® (P) and cetyl palmitate (CP) as carrier systems of moisturizers and sunscreens. The influence of the size and matrix crystallinity of the solid lipids on the occlusive factor, skin hydration and UV-protection were evaluated by in vitro and in vivo methods. The SLN were prepared by high-shear homogenization and ultrasound methods. Size, zeta potential and morphological characteristics of the samples were assessed by transmission electron microscopy (TEM) and thermotropic properties with differential scanning calorimetry (DSC) technique. Results of the assessments showed that SLN-CP significantly increases skin hydration and UV-protection, compared to SLN-GMS and SLN-P. It was demonstrated that the size of SLN, crystallinity index of solid lipid in SLN and probably other mechanisms besides the occlusive factor can influence skin hydration and UV-protection indices. Furthermore, findings of the assessments demonstrated significant difference between in vitro and in vivo assessments regarding occlusive factor and moisturizing effects. Findings of the present study indicate that the SLN-CP could be a promising carrier for sunscreens and moisturizers.

Formulation and pharmacokinetic evaluation of rifampicin solid lipid nanoparticles

“…Zeta potential of SLNs containing an elevated concentration of Glyceryl monostearate was more negative than Cetyl palmitate SLNs. This result agrees with that obtained by previous studies [10,14,15]. The reason is that Glyceryl monostearate is an ester of fatty acid which increased the particle surface negative charge [16].…”

“…Higher zeta potential leads to an increase in the physical stability of the system due to the increase in the electrostatic repulsion force between the particles. Values higher than +30 mV and lower than -30 mV, indicates good storage stability [9][10][11][12][13].…”

Novel Nanostructured Lipid Carriers with Photoprotective Properties Made from Carnauba Wax, Beeswax, and Kenaf Seed Oil

“…This circumstance might be due to the nanocrystalline size of the lipids in NLC, high specific surface area, and the presence of surfactants (Khameneh et al, ). When the UV filter was added into NLC, the orderly arranged lipid crystals were further disrupted and reduced the crystallization properties of NLC (Golmohammadzadeh et al, ). The endothermic events such as depression of the melting point and broadening of the melting peak were more pronounced in drug‐loaded NLC than that in SLN (Chaturvedi and Kumar, ) indicating that the drug (Univul A plus B) was solubilized in the amorphous form within the lipid matrix.…”

Protection and viability of fruit seeds oils by nanostructured lipid carrier (NLC) nanosuspensions

“…Calorimetric analysis was performed using differential scanning calorimeter (DSC). This method is used to obtain information about both physical and energetic properties of the lipid matrix [50], in this case the m.p. and presence of unincorporated oil [51].…”