Structure and dynamics of drug-carrier systems as studied by parelectric spectroscopy☆

Abstract

In the field of topical application without or with little systemic side-effects to reach antiinflammatory or anti-androgeneous effects, nanoparticles as carriers for drugs as betamethason-17-valerate, prednicarbate, prednisolone, RU 58841-myristate or cyproterone acetate have proven to enhance the transdermal delivery. This enhancement is closely connected to the interaction of the drug molecules with the lipid carrier systems, i.e. incorporation into the carriers or attachment to their surfaces. Whereas the techniques to measure the penetration profiles in the cutaneous region of the skin are well established in the case of fluorescence microscopy applied to thin slices of epidermis or being established in the case of multiphoton microscopy to monitor this fluorescence, the methods for the investigation of the type of interaction between drugs and carrier systems are relatively new: In the case of electron spin resonance the sample volumes have to be restricted to capillary sizes to avoid parelectric losses in the microwave cavities, in the case of the novel method of parelectric spectroscopy we are free from such restrictions. The application of the latter method will be presented here in detail concerning the underlying theory, the experimental aspects as well as the algorithms to extract the parameters of interest from the measured samples. As samples we restrict ourselves to solid lipid nanoparticles coated with different surfactants as carriers for drug-, dye-or spinlabel molecules.

Sequential Exposure to Carbon Nanotubes and Bacteria Enhances Pulmonary Inflammation and Infectivity

“…While engineered nonmodified SWCNT used in the study may compromise innate immune response and clearance of bacterial pathogens, thus raising questions regarding possible health aspects for producers and users (24), there are many examples of successful use of nanomaterials for delivery of anti-inflammatory agents such as antibiotics as well as steroidal (25) and nonsteroidal anti-inflammatory drugs (NSAIDs) (26). In addition, immunonanoparticles (i.e., nanoparticles functionalized with pathogen-specific antibodies) may serve as antimicrobial carriers for improving the stability and activity of antimicrobials in foods.…”

Drug Release and Skin Penetration from Solid Lipid Nanoparticles and a Base Cream: A Systematic Approach from a Comparison of Three Glucocorticoids

“…The theoretical background and the method are described in detail elsewhere [16,24] . Briefly, the dependence of particle mobility and density of the dipoles on the increasing drug concentration (0-0.3% of the GC) was measured by a frequency analyzer (type ZVR, Rohde and Schwarz, München, Germany).…”

Improving Topical Non-Melanoma Skin Cancer Treatment: In vitro Efficacy of a Novel Guanosine-Analog Phosphonate

“…In addition, scanning electron microscopy (Zeiss DSM 950 microscope; Zeiss, Jena, Germany) images were generated to study size and shape of the nanocarriers. Parelectric spectroscopy was employed to check for free drug molecules in the aqueous phase and to unravel the mode of OxBu interaction with the lipid matrix [23,25]. The amount of OxBu loaded to SLN (drug entrapment efficiency [17]) was quantified from the supernatant of centrifuged nanocarriers (70,000 g , 90 min) by high-performance liquid chromatography (HPLC).…”