Water solubility description

Description of Method. The water-soluble vitamins Bi (thiamine hydrochloride), B2 (riboflavin), B3 (niacinamide), and Be (pyridoxine hydrochloride) may be determined by CZE using a pH 9 sodium tetraborate/sodlum dIhydrogen phosphate buffer or by MEKC using the same buffer with the addition of sodium dodecyl-sulfate. Detection Is by UV absorption at 200 nm. An Internal standard of o-ethoxybenzamide Is used to standardize the method. 

Technology Description Hydrolysis is the process of breaking a bond in a molecule (which is ordinarily not water-soluble) so that it will go into ionic solution with water. Hydrolysis can be achieved by the addition of chemicals (e.g., acid hydrolysis), by irradiation (e.g., photolysis) or by biological action (e.g., enzymatic bond cleavage). The cloven molecule can then be further treated by other means to reduce toxicity. 

Ktihne, R., Ebert, R-U., Schtitirmann, G. Model selection based on structural similarity - method description and application to water solubility prediction. f Chem. Inf Model. 2006, 46, 636-641. 

Although the correlation between ket and the driving force determined by Eq. (14) has been confirmed by various experimental approaches, the effect of the Galvani potential difference remains to be fully understood. The elegant theoretical description by Schmickler seems to be in conflict with a great deal of experimental results. Even clearer evidence of the k t dependence on A 0 has been presented by Fermin et al. for photo-induced electron-transfer processes involving water-soluble porphyrins [50,83]. As discussed in the next section, the rationalization of the potential dependence of ket iti these systems is complicated by perturbations of the interfacial potential associated with the specific adsorption of the ionic dye. 

There are many polymers which have been used as physical matrices for controlled delivery of drugs. In this paper, these polymers are separated into water-soluble, biodegradable, and nonbiodegradable materials. A description of each class of polymers is presented. Examples of polymers from each class that have been used as drug delivery matrices and the criteria for their selection are included in this general review. 

Another solution to the problem of catalyst/product separation is the biphasic catalysis. The liquid biphasic catalysis became an attractive technology for potential commercial application of enantioselective homogeneous catalysis. The most important features of such systems are related to the fact that both reaction rate and e.s. may be influenced by the number of ionic groups in water-soluble ligand or by addition of surfactants. Descriptions of water-soluble ligands and the recent results in the rapidly progressing area of biphasic enantioselective catalysis are available in recent reviews [255,256],... 

The experimental procedure below describes the uptake of ciprofloxacin into sphingomyelin (SPM)/Chol LUVs. Drug delivery vehicles prepared from SPM/Chol often exhibit greater efficacy than those prepared from DSPC/Chol (13). Included is a description of the Bligh-Dyer extraction procedure (78), which involves partitioning the lipid and water-soluble drug into organic solvent and aqueous layers, respectively. This is necessary because lipid interferes with the ciprofloxacin assay. 

Preliminary results on toxicity of 3 species of Caribbean dinoflagellates have been reported, namely those on Gambierdiscus toxicus (25), Prorocentrum concavum (as cf. lima) (26), and mexicanum (as rhathymum) (27). A more detailed description of the effects of ether-soluble and water-soluble toxins from the same strain of toxicus on guinea pig ilea are presented elsewhere in... 

An alternative description of protein-containing RMs was given by Levashov et al. [148] from ultra-centrifugation studies. Water-soluble dyes (picric acid) were used to determine the molecular weights and sedimentation behavior of the non-protein-containing and protein-containing RMs. The proposed model involved two regimes of Wg (i) at low Wg (where the inner reverse micellar diameter was less than the protein diameter), the protein created a new RM around itself such that the volume of the inner cavity of the filled RM was essentially the volume of the solubihzed protein and (ii) at water contents where... 

A. General description Intron A (interferon alfa-2b recombinant) is a recombi-nantly derived water-soluble protein with a molecular weight of 19.3 kDa. It is obtained from the bacterial fermentation of a strain of Escherichia coli bearing a genetically engineered plasmid containing an interferon alfa-2b gene from human leukocytes. 

Frequently enzymes act in concert with small molecules, coenzymes or cofactors, which are essential to the function of the amino acid side chains of the enzyme. Coenzymes or cofactors are distinguished from substrates by the fact that they function as catalysts. They are also distinguishable from inhibitors or activators in that they participate directly in the catalyzed reaction. Chapter 10, Vitamins and Coenzymes, starts with a description of the relationship of water-soluble vitamins to their coenzymes. Next, the functions and mechanisms of action of coenzymes are explained. In the concluding sections of this chapter, the roles of metal cofactors and lipid-soluble vitamins in enzymatic catalysis are briefly discussed. 

Materials used in controlled release products. Following is a list of the most commonly used water-soluble polymers and plasticizers for controlled release coating, as well as a description of their properties. This list is not meant to be comprehensive of all materials ever proposed for use in such products. 

Product Chemical description HLB Water solubility Colour and form at 25°C... 

The sorbents were hydrophobic Teflon and hydrophobic polystyrene (PS). These sorbents were supplied as negatively charged colloidal particles having smooth hydrophobic surfaces. In addition, PS particles at the surface of which oligomers (8-mers) of ethylene oxide ((EO)8) were grafted at a density of one (EO)g-moiety per 2.5 nm2, were used. Because of the water-solubility of EO, these flexible (EO)8 oligomers reach out from the surface into the aqueous solution causing a hairy sorbent surface. A more detailed description of these sorbent materials is described elsewhere.30,31... 

First, it is necessary to establish the phase diagram of the aqueous two-phase system formed by water and two water-soluble polymers. Second, a method must be established for calculating the distribution coefficient of a biomolecule that partitions between the two aqueous phases. A simple molecular-thermodynamic description is provided by the osmotic virial... 

Brief Process Description. Suitably sized wood blocks are fed to a fixed bed gasifier operating essentially at atmospheric pressure. The gasifier is fired with pure oxygen at a rate of about 0.4 tons/ton of methanol product. After heat recovery, the gas is blown through a Lymn washer where the tar and water soluble organics and salts are removed by countercurrent contact with water. 

Disperse dyes were invented to dye the first hydrophobic fiber developed, namely cellulose acetate, and were initially called acetate dyes.25 The term disperse dyes is more appropriate, because these dyes are suitable for a variety of hydrophobic fibers and it is descriptive of their physical state in the dye-bath. Disperse dyes have extremely low water solubility and to be applied from this medium they must be (1) dispersed in water using a... 

Dudley, L. M. and B. L. McNeal. 1987. A model for electrostatic interactions among charged sites of water-soluble, organic polyions. 1. Description and sensitivity. Soil Sci. 143 329. 

Conjugation of lipophilic xenobiotics to polar cellular constituents renders the xenobiotic more water-soluble. While the lipophilic parent xenobiotics could readily diffuse into the cells, the increase in polarity associated with conjugation greatly reduces the ability of the compound to diffuse across the lipid bilayer of the cell membrane thus trapping the compound within the cell. The polar conjugates must therefore rely upon active transport processes to facilitate efflux from the cell. Hepatocytes, as well as other cells involved in chemical detoxification, are rich with members of the ATP-binding cassette superfamily of active transport proteins (ABC transporters). Cellular efflux of xenobiotics by these transporters is often referred to as Phase III elimination because Phase I or II detoxification processes often precede and are a requirement of Phase III elimination. A detailed description and discussion of elimination and transporters is presented in Chapter 15. 

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