Determining the absolute surface hydrophobicity of microparticulates using thin layer wicking

Analysis of the topochemical effects of dielectric-barrier discharge on cellulosic fibers

“…Figure 6 provides the contact angles determined using the Washburn equation for the wicking of a vertical column. The Washburn (1921) equation has been applied to studying the wettability of fibers in numerous studies (Winspear 1979;Hodgson and Berg 1988;Danino and Marmur 1994;Hoecker and Karger-Kocsis 1996;Pillai and Advani 1996;Chen and McMorran 1999;Norris et al 1999;Shi et al 2000;Hajnos et al 2003). In this study, a decreased contact angle at lower treatment levels was observed for the TMP samples.…”

“…where h is the vertical wicking height, t the time, r the average pore radius, c the surface tension of water, h the contact angle, and g the viscosity of water was applied as in past studies modeling the behavior of papermaking fibers and related materials (Winspear 1979;Hodgson and Berg 1988;Danino and Marmur 1994;Hoecker and Karger-Kocsis 1996;Pillai and Advani 1996;Chen and McMorran 1999;Norris et al 1999;Shi et al 2000;Hajnos et al 2003). Mercury porosimetry was performed by Micromeritics Instrument Corporation to determine the average pore radius.…”

Experimental and Computational Methods Pertaining to Surface Tension of Pharmaceuticals

“…where t is the time required for solvent to rise x millimeters above the solvent through the MPs, γ and η are the surface tension and viscosity of the solvent, cos  is the cosine of the contact angle and r is the internal radius of the capillary (Norris et al, 1999;Ramírez-Flores et al, 2010;Xue et al, 2006). The wetting of small particles and porous materials is a very important phenomenon in pharmaceutical technologies for wettability studies of drug powder and drug manufacturing with related processes.…”

The Physical Properties of Biogels and their Permeability for Macromolecular Drugs and Colloidal Drug Carriers

“…Additionally, very recently a thin-layer wicking method was presented for the determination of the absolute surface hydrophobicity of colloidal drug carriers. 103 According to various authors, constituents that create hydrophobic regions in biogels are the nonglycosylated peptide parts of mucines that may interact with fatty acids and lipids. 68,[104][105][106][107] The presence of hydrophobic regions in gastric and duodenal mucus has been shown by the use of fluorescent hydrophobic dyes like 1-anilino-naphtalene-8-sulfonic acid (ANS) and 1,6-diphenyl-1,3,5-hexatriene (DPH).…”