Abstract: The invention relates to drug-free or drug-loaded lipid particles of a mixed matrix made of solid and liquid lipids, and to a method for producing highly concentrated lipid particle dispersions of solid-liquid particles having a lipid content of from 30% to 95% or a solids content of from 30% to 95% (lipid and stabilizer), which in contrast to biamphipileic cremes are integer particles, and/or which upon dilution of the highly concentrated particle dispersions with the outer phase result in free-flowable particle dispersions.

Abstract: The invention provides apparatus and methods for measuring oxygen tensions in biological systems utilizing physiologically acceptable paramagnetic material, such as India ink or carbon black, and electron paramagnetic resonance (EPR) oximetry. India ink is introduced to the biological system and exposed to a magnetic field and an electromagnetic field in the 1-2 GHz range. The EPR spectra is then measured at the biological system to determine oxygen concentration. The EPR spectra is determined by an EPR spectrometer that adjusts the resonator to a single resonator frequency to compensate for movements of the biological system, such as a human or animal. The biological system can also include other in vivo tissues, cells, and cell cultures to directly measure pO.sub.2 non-destructively. The paramagnetic material can be used non-invasively or invasively depending on the goals of the pO2 measurement.