Biomedical subjects

Sylvia A Wissing

Publications and source records attributed to Sylvia A Wissing.

5 recordsLinked to original sources

PubMed2006

Artemisia arborescens L essential oil-loaded solid lipid nanoparticles for potential agricultural application: preparation and characterization.

The aim of this study was to formulate a new delivery system for ecological pesticides by the incorporation of Artemisia arborescens L essential oil into solid lipid nanoparticles (SLN). Two different SLN formulations were prepared following the high-pressure homogenization technique using Compritol 888 ATO as lipid and Poloxamer 188 or Miranol Ultra C32 as surfactants. The SLN formulation particle size was determined using Photon correlation spectroscopy (PCS) and laser diffraction analysis (LD). The change of particle charge was studied by zeta potential (ZP) measurements, while the melting and recrystallization behavior was studied using differential scanning calorimetry (DSC). In vitro release studies of the essential oil were performed at 35 degrees C. Data showed a high physical stability for both formulations at various storage temperatures during 2 months of investigation. In particular, average diameter of Artemisia arborescens L essential oil-loaded SLN did not vary during storage and increased slightly after spraying the SLN dispersions. In vitro release experiments showed that SLN were able to reduce the rapid evaporation of essential oil if compared with the reference emulsions. Therefore, obtained results showed that the studied SLN formulations are suitable carriers in agriculture.

Artemisia↗

PubMed2005

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) -- structural investigations on two different carrier systems.

Two different types of colloidal lipid particles are presented and compared as innovative carrier systems. Size distribution and storage stability of formulations produced by hot high pressure homogenisation in lab and medium scale production were investigated by laser diffractometry (LD) and photon correlation spectroscopy (PCS). Nanoparticles were characterised by their melting and recrystallisation behaviour recorded by differential scanning calorimetry (DSC). Electron microscope investigations were also carried out showing the particulate character of these carriers. Reasons for observed differences in loading capacity are discussed and possibilities for dermal application are described.

Biocompatible Materials↗

PubMed2004

Structural characterization of Q10-loaded solid lipid nanoparticles by NMR spectroscopy.

PURPOSE: The structure of loaded solid lipid nanoparticles (SLN) has been studied to elucidate the incorporation of coenzyme Q10. METHODS: Solid-state nuclear magnetic resonance (NMR) has been applied as the principal analytical approach. In order to characterize the integration of the active ingredient coenzyme Q10 inside the solid lipid matrix, measurements of the spin-lattice relaxation time in the rotating frame have been performed. RESULTS: A pattern of spin diffusion between protons of the lipid and protons of the coenzyme Q10 has been observed, which indicates two different fractions of the active ingredient: whereas the majority (60%) of the coenzyme Q10 is found to be homogeneously mixed with the solid lipid, the residual amount of 40% clearly forms a separate, solid phase associated to the particles. CONCLUSIONS: A large portion of the active ingredient has been integrated homogeneously. Another, smaller fraction forms separate domains on the nanometer scale.

Drug Carriers↗

PubMed2003

Cosmetic applications for solid lipid nanoparticles (SLN).

Solid lipid nanoparticles (SLN) are novel delivery systems for pharmaceutical and cosmetic active ingredients. This paper highlights advantages of SLN for cosmetic applications. The dependence of the occlusive effect on the particle size of SLN due to film formation is presented by in vitro data. An in vivo study showed that addition of 4% SLN to a conventional o/w cream lead to an increase of skin hydration of 31% after 4 weeks. The application of SLN as physical sunscreens and as active carriers for molecular sunscreens has also been investigated. The amount of molecular sunscreen could be decreased by 50% while maintaining the protection level compared to a conventional emulsion.

Administration, Topical↗

PubMed2003

The influence of solid lipid nanoparticles on skin hydration and viscoelasticity--in vivo study.

Effects on skin hydration and viscoelasticity are important criteria during the development of novel cosmetic formulations. This study focuses on the in vivo performance of a conventional o/w cream and of the same cream enriched with solid lipid nanoparticles (SLN). Influences on skin hydration and viscoelastic properties were investigated with validated devices (Corneometer and Cutometer). After an application period of 4 weeks, significant changes in skin hydration were detected for both formulations. The SLN-enriched cream was significantly more effective than the conventional cream (+24% for the cream and +31% for the SLN-cream). The viscoelastic parameters UF and UA/UF remained almost unchanged, which is attributed to the young age of the volunteers. At this stage, SLN represent a promising compound for hydrating new cosmetic formulations.

Administration, Topical↗