Influence of emulsifiers on the crystallization of solid lipid nanoparticles

Abstract

The crystallization temperature and polymorphism of tripalmitin nanoparticles in colloidal dispersions prepared by melt-homogenization and stabilized with different pharmaceutical surfactants (sodium glycocholate, sodium oleate, tyloxapol, Solutol HS 15, Cremophor EL) and their combinations with soybean phospholipid (Lipoid S100) were investigated to establish the influence of the emulsifiers on these parameters. There were no major effects on the crystallization temperature but remarkable differences in the time-course of polymorphic transitions after crystallization of the triglyceride particles indicate interaction between the surfactant layer and the triglyceride matrix. The metastable alpha-modification was most stable in dispersions solely stabilized with glycocholate. Upon fast cooling from the melt, these dispersions form an uncommon type of alpha-modification that displays only a very weak small-angle reflection indicating poor ordering between triglyceride layers. Slow crystallization of these glycocholate-stabilized nanoparticles yields the usual alpha-form. Electron microscopic investigations reveal that, in both cases, the particles in the alpha-modification are less anisometric than those of the stable beta-form. These results indicate that major rearrangements still may take place in solid lipid nanoparticles after recrystallization.

Evaluation of the physical stability of SLN and NLC before and after incorporation into hydrogel formulations

“…it increases with the decrease of the mean particle diameter [5]. Lipid aqueous dispersions with small nanoparticles and narrow size distributions are preferably obtained by emulsification of the molten matrix lipid in a hot aqueous phase with adequate emulsifying agents and subsequent crystallization of the dispersed lipid matrix [6]. Therefore, our systems were prepared by hot high pressure homogenization technique (hot HPH).…”

Etoposide-loaded nanoparticles made from glyceride lipids: Formulation, characterization, in vitro drug release, and stability evaluation

“…8 Much research is available on formulation, characterization, 9 in vitro degradation, lipid recrystallization behavioral studies by techniques 10 such as differential scanning calorimetry, 11 small-angle and wide-angle radiograph diffractometry, 12 etc, and their in vitro drug release potential. 11 Extensive research by Bunjes and coworkers [13][14][15] reports on the crystalline properties of lipids and their recrystallization patterns during nanoparticle preparation and the influence of nanoparticle size on the recrystallization pattern.…”

Preparation and characterization of nanosized Ag/SLN composite and its viability for improved occlusion

“…The composite Ag/PAN has a zeta potential of 13.5 Mv that indicated lower stability for the composite compared to the pure SLN. However The zeta potential values of all the nano suspension indicated (Table 1) moderate stability of the suspensions with limited flocculation (Bunjes et al 2003).…”

“…However, this rule cannot strictly be applied to systems which contain steric stabilizers, because the adsorption of stearic stabilizer will decrease the zeta potential due the shift in the shear plane of the particle. They prevent aggregation of nanoparticles in suspension (Bunjes et al 2003). The stabilizer TWEEN-80 that is used in the preparations of the samples was known to sterically stabilize the nanoparticles.…”