Factors that Influence Solubility

When the solubility is limited by the strength of the crystal lattice, solubility is dependent on melting of the solid solute as represented by  

The fact that melting point has often been shown to be a poor parameter to judge aqueous solubilities of co-crystals indicates that solubility is limited by solvation (hydrophobicity of the solute) and not by lattice energy.Several 

Solvent-solute interactions are often the main resistance to the observed solubility of hydrophobic molecules in aqueous media. The deviation between ideal and observed solubility is quantitatively expressed by  

Lattice strength and solvation contributions to solubility can be calculated from measurement of melting point, enthalpy of melting, and equilibrium solubility in solvents of interest according to  

Co-former solubility has also been correlated with co-crystal solubility for a series of co-crystals of the same drug. This behavior is a result of co-former decreasing the solvation barrier for a co-crystal to an extent proportional to that of the pure co-former. While universal indicators of co-crystal solubility would be useful, each case requires a careful analysis of the factors that influence solubility. Similar behavior has been reported for salt solubility.  

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Emulsification is a stabilizing effect of proteins a lowering of the interfacial tension between immiscible components that allow the formation of a protective layer around oil droplets. The inherent properties of proteins or their molecular conformation, denaturation, aggregation, pH solubility, and susceptibility to divalent cations affect their performance in model and commercial emulsion systems. Emulsion capacity profiles of proteins closely resemble protein solubility curves and thus the factors that influence solubility properties (protein composition and structure, methods and conditions of extraction, processing, and storage) or treatments used to modify protein character also influence emulsifying properties. 

Know the factors that influence solubility and rate of solution. Be familiar with different types of solution. 

In Section 4-2, part 5, we listed the solubility guidelines for aqueous solutions. Now we investigate the major factors that influence solubility. 

The structure of repeat units of individual polymers constituting a blend, as well as the nature of interactions between polymers in a blend are the factors that influence solubility characteristics of a blend. Thus, solubility is affected by ... 

Your list could be extensive since any factor that influences the rate and/or amount of product formed, ie the fermentation conditions or the characteristics of the process organism could influence productivity, eg pH, temperature, solubility of substrate. 

Absorption across biological membranes is often necessary for a chemical to manifest toxicity. In many cases several membranes need to be crossed and the structure of both the chemical and the membrane need to be evaluated in the process. The major routes of absorption are ingestion, inhalation, dermal and, in the case of exposures in aquatic systems, gills. Factors that influence absorption have been reviewed recently. Methods to assess absorption include in vivo, in vitro, various cellular cultures as well as modelling approaches. Solubility and permeability are barriers to absorption and guidelines have been developed to estimate the likelihood of candidate molecules being absorbed after oral administration. ... 

Factors that influence drug dialyzability in chronic ambulatory peritoneal dialysis include drug-specific characteristics (e.g., molecular weight, solubility, degree of ionization, protein binding, and VD) and intrinsic properties of the peritoneal membrane (e.g., blood flow, pore size, and peritoneal membrane surface area). 

There are many factors that influence the outcome of enzymatic reactions in carbon dioxide. These include enzyme activity, enzyme stability, temperature, pH, pressure, diffusional limitations of a two-phase heterogeneous mixture, solubility of enzyme and/or substrates, water content of the reaction system, and flow rate of carbon dioxide (continuous and semibatch reactions). It is important to understand the aspects that control and limit biocatalysis in carbon dioxide if one wants to improve upon the process. This chapter serves as a brief introduction to enzyme chemistry in carbon dioxide. The advantages and disadvantages of running reactions in this medium, as well as the factors that influence reactions, are all presented. Many of the reactions studied in this area are summarized in a manner that is easy to read and referenced in Table 6.1. 

The existence of biases between labs is a clear indication that the operating principles that are used to describe a measurement process are not being realized in practice. In some cases the operator s technique fails to account for a factor that influences the measurement. In other cases the model that is used to describe the measurement process contains approximations that are violated in using the method. Examples include the back pressure correction, which can be important in situations where the gas is highly soluble in the polymer, the correction for the volume increase in manometric measurements using mercury columns 5,... 

Aluminium is the third most abundant element in the earth s crust and is used widely in the manufacture of construction materials, wiring, packaging materials and cookware. The metal and its compounds are used in the paper, glass and textile industries as well as in food additives. Despite the abundance of the metal, its chemical nature effectively excludes it from normal metabolic processes. This is due largely to the low solubility of aluminium silicates, phosphates and oxides that result in the aluminium being chemically unavailable. However, it can cause toxic effects when there are raised concentrations of aluminium in water used for renal dialysis. These effects are not seen when aluminium is at the concentrations usually present in drinking water. There is currently much activity to examine the factors that influence uptake of aluminium from the diet. 

The permeability of the skin to a toxic substance is a function of both the substance and the skin. The permeability of the skin varies with both the location and the species that penetrates it. In order to penetrate the skin significantly, a substance must be a liquid or gas or significantly soluble in water or organic solvents. In general, nonpolar, lipid-soluble substances traverse skin more readily than do ionic species. Substances that penetrate skin easily include lipid-soluble endogenous substances (hormones, vitamins D and K) and a number of xenobiotic compounds. Common examples of these are phenol, nicotine, and strychnine. Some military poisons, such as the nerve gas sarin (see Section 18.8), permeate the skin very readily, which greatly adds to then-hazards. In addition to the rate of transport through the skin, an additional factor that influences toxicity via the percutaneous route is the blood flow at the site of exposure. 

The pharmacokinetic phase of drug action includes the Absorption, Distribution, Metabolism and Elimination (ADME) of the drug. Many of the factors that influence drug action apply to all aspects of the pharmacokinetic phase. Solubility (see Section 3.3), for example, is an important factor in the absorption, distribution and elimination of a drug. Furthermore, the rate of drug dissolution, that is, the rate at which a solid drug dissolves in the aqueous medium, controls its activity when a solid drug is administered by enteral routes (see Section 2.6) as a solid or suspension. 

Major factors that influence distribution are the solubility (see Section 3.3) and stability (see Biological half life, Section 8.4.1) of drugs in the biological environment of the blood. Sparingly water soluble compounds may be deposited in the blood vessels, leading to restriction in blood flow. Drug stability... 

In spite of these major limitations, considerable progress has been made in understanding many of the important factors that influence subsurface water chemistry. Na+, Ca2+ and Cl- account for the major portion of dissolved components in most brines (Figure 8.6). Ca2+, which can comprise up to 40% of the cations, usually increases relative to Na+ with depth (Figure 8.7). Br and organic acids are commonly found at concentrations of 1 to 2 g L1 (Land, 1987). The bicarbonate concentration is largely limited by carbonate mineral solubility, and sulfate is generally found in low concentrations as a result of bacterial and thermal reduction processes. 

Kamlet, M.J., Doherty, R.M., Taft, R.W., Abraham, M.H., Veith, G.D., Abraham, D.J. (1987) Solubility properties in polymers and biological media. 8. An analysis of the factors that influence toxicities of organic nonelectrolytes to the golden orfe fish (leuciscus idus melanotus). Environ. Sci. Technol. 21(2), 149-155. 

The factors that influence corrosion of steels in soils are the type of soil moisture content and the position of the water table soil resistivity and soluble ion content soil pH oxidation-reduction potential and the role of microbes present in soil. The exposure of a buried pipe to the soil environment is illustrated in Figure 4.2. The steel pipe is exposed to both meteoric water passing through ground surface and the water in the ground. The meteoric water may be acidic due to the presence of carbon dioxide and sulfur dioxide in the atmosphere. The soil water may be acidic in addition to some dissolved minerals. The steel pipe is partially above the water table with the rest below the water. The pH and the dissolved ions in the ground water provide a corrosive environment. 

In solutions, the most important physical factors that influence the solubility of ingredients are type of fluid, mixing equipment, and mixing operations. Generalized Newtonian fluids are ideal fluids for which the ratio of the shear rate to the shear stress is constant at a particular time. Unfortunately, in practice, usually liquid dosage forms and their ingredients are non-Newtonian fluids in which the ratio of the shear rate to the shear stress varies. As a result, non-Newtonian fluids may not have a well-defined viscosity [32],... 

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