Low productivities of bioprocesses using gaseous carbon and energy sources are usually caused by the low solubility of those gases (e.g., H2 and CO). It has been suggested that increasing the partial pressure of those gases will result in higher dissolved concentrations and should, therefore, be helpful to overcome this obstacle. Investigations of the late 1980s with mixtures of hydrogen and ca...

Proton magnetic resonance spectroscopy ((1)HNMR) studies on inclusion compounds of zaleplon with hydroxypropyl-β- cyclodextrin (HPβCD) were carried out in order to elucidate the strength and binding mode of association. Chemical shift measurements revealed that inclusion complexes of zaleplon and HPβCD were formed by penetration of aromatic rings into the HPβCD cavity from the wider rim side wi...

Amelogenins are a group of extracellular enamel matrix proteins which are believed to be involved in the regulation of the size and habits of forming enamel crystals. The aim of this study was to compare the solubility properties of several amelogenins at various pH (from 4.0 to 9.0) at constant ionic strength (IS), and to examine the influence of buffer composition, IS, and divalent metal ions...

Enhancement of solubility is one of the difficult tasks which become challenges in formulation development of orally administered drug with poor aqueous solubility. Poor water solubility of drugs often causes significant problems in producing formulations of sufficiently high bioavailability, preventing effective use of the drugs. 'Mixed-solvency ' concept is the phenomenon to increase the solu...

The most common stoichiometry of drug/cyclodextrin complexes is 1:1, i.e. one drug molecule forms a complex with one cyclodextrin molecule, and the most common method for stoichiometric determination during formulation studies is the phase-solubility method. However, in recent years it has becoming increasingly clear that solubilizing effects of cyclodextrins are frequently due to the formation...

Introduction: Tooth enamel mineral loss is influenced by its solubility product value, which is fundamental to the understanding of de- and remineralization resulting from a carious or erosive challenge. Published pKsp values for human enamel and hydroxyapatite range from 110 to 126 suggesting a heterogeneous nature of enamel solubility. However, this range of values may also result from the va...

This paper presents trends in the high pressure solubility measurements of long chain saturated methyl esters (methyl decanoate, methyl dodecanoate, methyl tetradecanoate, methyl hexadecanoate, methyl octadecanoate and methyl docosanoate) in supercritical ethane between 313 K and 353 K and for mass fractions between 0.65 and 0.018. The data shows generally a linear relationship between the solu...