Partikelgröße und Permeation

Particle Size and Permeation Using the Tesafilm (adhesive tape)-tear off method and by microscopie evaluation of the resulting films in polarized light the penetration of crystalline particles in the horny skin can be followed. As seen with examples, such as Tolnaftat, Na₂CO₃ · 10 H₂O and KF 224, crystalline particles can permeate upto remarkable depths in the horny skin. These studies indicate that the particle size of the crystals are only of minor significance. Possibly the depth of penetration depends more upon the crystalline form and on the solubility of substances in the components of the horny layer. Such processes can be determining factors for the intensity and duration of action of dermatological agents.     

Die On-Line-Messung von Partikelgrößenverteilungen in Gasen und Flüssigkeiten

On-line measurement of particle size distribution in gases and liquids . The importance of rapid response and on-line analyses of particle size distributions is becoming increasingly important in industry for the continuous supervision of product quality and the control of production processes. Instrument manufacturers already offer a considerable number of rapid response devices which can be used for systems with extremely low solids concentrations as well as for the analysis of bulk material and highly concentrated suspensions and aerodispersions. Some of these instruments are already superior to older methods of analysis. They not only save time and labour but have also opened a new dimension in direct supervision and control of production processes. This paper surveys the most important on-line measuring techniques and instruments.