Lypophilic

Further, facilitated membrane separations by fixed-site heteropolysiloxane membranes for a mixture of seven amino acids provided a good selectivity (S = 9-10, calculated as flux ratio) for lypophilic amino acids (L-phenylalanine and L-leucine) (Figure 10.3) [30,31]. 

Ryan [36] developed a method to determine the relative degree of crystallinity (RDC) of imipenem in lypophilized combination products containing imipenem and amorphous cilastatin sodium. He used the relationship... 

Fig. 30. Schematic representation of lypophilic, radiolabeled complexes which have been encapsulated in lipid-based nanoparticles (150).

Horvath recognized that SAPC solved the problem posed by the solubility of lypophilic substrates in aqueous biphasic catalysis with water-soluble homogeneous catalysts. He compared biphasic aqueous-organic catalysis with SAPC, in order to clarify whether in SAPC the catalyst remained dissolved in the... 

Prenylation has been implicated in the prevention of HIV infection. Statins have been used to inhibit HIV infection by interacting with Rho GTPases and suppress the intercellular adhesion required for viral entry. In another study with statins and HIV the mechanism of action was elucidated. The lypophilic statins... 

H. Kunieda and K. Shinoda Phase Behavior in Systems of Nonionic Surfac-tant/Water/Oil Around the Hydrophilic-Lypophilic-Balance-Temperature. J. Dispersion Sci. Technol. 3, 233 (1982). 

Aqueous solubility is typically inversely proportional to lypophilicity. Lypophilicity represents the affinity of a molecule (or moiety) for a lypophilic environment. Dmg solubility is also an important attribute to its oral absorption and subsequent permeability through membranes. In medicinal chemistry, solubility for a 1-mg kg dose of 5,50, and 500 p,g mL is estimated to be low, medium, and high, respectively (Van de Waterbeemd, 2002). Solubility characteristics have long been recognized as important in pharmaceutical chemistry and are part and parcel of the drug design process. For example, the solubility can be used to determine the maximal absorbable dose (MAD), that is. 

To solubilize insoluble lypophilic or hydrophobic active substances in an aqueous medium, BASF Pharmaceutical... 

The operative tank can be utilized as a full capacity still if it is provided with an internal heat exchanger, otherwise an additional still, smaller in size, is necessary to perform the distillation step and to clean the dirty liquid CO2. As the percentage of lypophilic substances... 

Capsicum juices by lypophilization and subsequent LLE by three different solvents. 

The product (being lypophilic and thus insoluble in DMF), however, precipitated in large measure from the reaction mixture. This was one of those all-too-infrequent moments that every mentor relishes. When the... 

Jprgensen et al. 141 utilized this molecular organization process (dumbbell-like stacking) to incorporate tetrathiafulvalene (TTF a substrate currently of interest in such areas as molecular electronics and organomagnetism) within the central lypophilic region (Scheme 4.33) of the self-assembled, supramolecular structures. A multistage synthesis... 

The pH of a solution influences the extent of adsorption. The majority of pharmaceutically active drugs are weak acids or weak bases. The degree of ionization and solubility of the adsorbate drug molecule are dependent on pH. As described above, more ionized (i.e., polar) and soluble adsorbates adsorb much less than their unionized forms (i.e., lypophilic) do. For amphoteric adsorbates, a maximum adsorption capacity occurs at the isoelectric point (IEP), where the net charge of the adsorbate becomes zero, and at the lowest solubility. In general, pH and solubility... 

The most frequently used solvent for flavones is hexadeuterodi-methylsulfoxide (DMSO- 56) and tetradeuteromethanol (CD3OD). For lypophilic flavone aglycones, solvents such as carbontetrachloride (CCI4) are recommended. 

Although the partition coefficient alone does not provide information regarding absorption, it characterizes the lypophilic-hydrophilic balance of a drug and supports the screening of compounds for their biological properties. 

The pollutants metabolites resulting from the biotransformation could enter the blood and be eliminated from the body through urine, skin secretion, faeces or breath (Fig. 2). Hydrophilic and lypophilic compounds behave... 

The biotransformation is the sum of the processes by which a pollutant is subject to chemical change in living organisms. During biotransformation a large number of enzymes and pathways are involved and the common activity of most of them is that they transform lypophilic pollutants into more polar metabolites. Biotransformation (metabolic alteration) of pollutant molecules occurs mainly in the liver, but to some extent also in skin, kidney, placenta, plasma, intestine or brain (Nove et al., 2000). Extrahepatic tissues... 

To decide which fractions to pool, samples of fractions under peaks are analyzed by analytical HPLC. Those that are considered pure are pooled and lypophilized. The advantage of the H2O-ACN-TFA elution system, in addition to the sharp peaks and generally high resolution, is that this mobile phase system consists of volatile solvents and TFA that can be removed... 

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