The encapsulation effect of UV molecular absorbers into biocompatible lipid nanoparticles

The efficiency of a cosmetic product depends not only on the active ingredients, but also on the carrier system devoted to improve its bioavailability. This article aims to encapsulate two couples of UV molecular absorbers, with a blocking action on both UV-A and UV-B domains, into efficient lipid nanoparticles. The effect of encapsulation on the specific properties such as sun protection factor and photostability behaviour has been demonstrated. The lipid nanoparticles with size range 30-350 nm and a polydispersity index between 0.217 and 0.244 are obtained using a modified high shear homogenisation method. The nanoparticles had spherical shapes with a single crystallisation form of lipid matrices characteristic for the least ordered crystal structure (α-form). The in vitro determination of photoprotection has led to high SPF ratings, with values of about 20, which assure a good photoprotection and filtering about 95% of UV radiation. The photoprotection effect after irradiation stage was observed to be increased more than twice compared to initial samples as a result of isomerisation phenomena. All the results have shown that good photoprotection effect and improved photostability could be obtained using such sunscreen couples, thus demonstrating that UV absorbers-solid lipid nanoparticles are promising carriers for cosmetic formulations

Specific interactions within micelle microenvironment in different charged dye/surfactant systems

AbstractThe interactions of two ionic dyes, Crystal Violet and Methyl Orange, with different charged surfactants and also with a nonionic surfactant were investigated using surface tension measurements and visible spectroscopy in pre-micellar and post-micellar regions. It was found that for the water dominant phase systems the dye was localized between the polar heads, at the exterior of the direct micelle shells for all the systems. For the oil dominant phase systems, in case of the same charged dye/surfactant couples, the dye was localized in the micelle shell between the hydrocarbon chain of the surfactant nearby the hydrophilic head groups while for nonionic surfactant and oppositely charged dye/surfactant, localization of dye was between the oxyethylenic head groups towards the interior of the micelle core. Mixed aggregates of the dye and surfactant (below the critical micellar concentration of cationic surfactant), dye-surfactant ion pair and surfactant-micelles were present. The values of equilibrium constants (for TX-114/MO and TX-114/CV systems were 0.97 and 0.98, respectively), partition coefficients between the micellar and bulk water phases and standard free energy (for the nonionic systems were −12.59kJ/mol for MO and −10.97kJ/mol for CV) were calculated for all the studied systems. The partition processes were exothermic and occurred spontaneously

Vegetal bioproducts with antioxidant activity for prophylactic and therapeutic effect

This paper presents the extractive technological process and processing of the selective vegetal extracts from the Rosmarinus officinalis L. species in order to obtain some vegetal bioproducts with proven antioxidant activity. By combining various active fractions, new vegetal bioproducts have been obtained and have been physically and chemically characterised (infrared, ultraviolet visible spectroscopy, chemiluminescence, determination of flavonoids, polyphenols, and polyphenolcarboxilic acids content) and finaly biologically tested. The antioxidant activity of Rosmarinus officinalis extracts have been evaluated by two techniques, in vitro chemiluminescence and ex vivo biological tests, both of them recommending the vegetal bioproducts for prophylactic and therapeutic purposes

NIR Study of Chemically Modified Cellulosic Biopolymers

Near-infrared spectral analysis was useful to quantify the ester content of chemically modified cellulose and lignocellulosics. Two kinds of samples were studied, as long aliphatic-chain cellulose esters and wood sawdust chemically-modified either by anhydrides or by ethylene carbonate. It was possible to determine the degree of substitution (DS) of such samples through a correlation by partial least square (PLS) of second-order derivative of NIR spectra. This technique was efficient even when DS values were low, which is difficult to do by using FTIR. It was also possible to distinguish reagent molecules that were attached to the cellulosic substrate by hydrogen bonding from those linked by covalent bonding