Aqueous solution formulations

Glyphosate, a herbicide, is one example of a water-soluble amine salt of an AI acid that is usually delivered as a solution. Stabilizers and surfactants are combined in the formulation for effective application. The surfactant of choice, in fact critical for activity, is a tallow amine ethoxylate. This surfactant appears to be involved with translocation of the glyphosate across the leaf cuticle so the AI can be moved through the plant to the roots [7]. Example aqueous solution formulations are shown in Table 12.1. 

Phenyldiazonium chloride and other similar diazonium compounds are very soluble in water, are completely insoluble in ether and other organic solvents, and are completely dissociated in aqueous solution to organic cations and inorganic anions (e.g., chloride ions) a convenient formulation is therefore, for example, CjHjNj+CP. 

The merits of (enantioselective) Lewis-acid catalysis of Diels-Alder reactions in aqueous solution have been highlighted in Chapters 2 and 3. Both chapters focused on the Diels-Alder reaction of substituted 3-phenyl-1-(2-pyr idyl)-2-prop ene-1-one dienophiles. In this chapter the scope of Lewis-acid catalysis of Diels-Alder reactions in water is investigated. Some literature claims in this area are critically examined and requirements for ejfective Lewis-acid catalysis are formulated. Finally an attempt is made to extend the scope of Lewis-acid catalysis in water by making use of a strongly coordinating auxiliary. 

Aqueous solutions of propylene glycol display excellent antifree2e properties and are therefore valuable as low temperature heat-transfer fluids. For apphcations involving indirect food contact, heat-transfer fluids formulated with the USP grade product are preferred, since there could be inadvertent contact with a food product. These fluids are commonly used in the brewing and dairy industries as well as in refrigerated display cases in retail grocery stores. 

Neutralizing Lotion. The principal active ingredient of cold wave neutralizers is usually an oxidizing agent. The most popular is hydrogen peroxide [7722-84-1J, employed at a concentration of 1—2% it continues to find widespread use. Aqueous solutions of sodium bromate [7789-38-0] at a concentration of 10—20% occasionally are used and are technically preferred over the peroxide formulations because of excellent stabiUty and absence of hair bleaching. Neutralizing powders appear to be on the decline but formulations stiU in use consist of sodium perborate [7632-04-4] combined with hexametaphosphates to improve solubiUty in hard water. 

Liquid Dosage Forms. Simple aqueous solutions, symps, elixirs, and tinctures are prepared by dissolution of solutes in the appropriate solvent systems. Adjunct formulation ingredients include certified dyes, flavors, sweeteners, and antimicrobial preservatives. These solutions are filtered under pressure, often using selected filtering aid materials. The products are stored in large tanks, ready for filling into containers. QuaUty control analysis is then performed. 

A.mmonium ben ate [1863-63-41], C H COONH, mp, 198°C. This is a dull white powder which gradually loses ammonia on exposure to air. Its aqueous solution, it is slightly acidic. Ammonium benzoate has been suggested as a component in certain mbber formulations (40) and as a preservative in paints and glues. 

Ch oline in the form of choline base (hydroxide) is a strong organic base with a pH of approximately 14. This product can have industrial apphcations where it is important to replace inorganic bases with organic materials. Ch oline base is currently used in the formulation of photoresist stripping products for use in the printed wire board industry. Dilute aqueous solutions (5%) of ch oline base that have very low concentrations of metallic ions have been utilized for apphcations in the semiconductor industry. 

Steric Selectivity. In addition to the normal regularities that can be rationalized by electronic considerations, steric factors are important in coordination chemistry. To illustrate, 8-hydroxyquinoline, or 8-quinolinol (Hq) [148-24-3J, at 100°C precipitates both Mg " and AE" from aqueous solution as hydrated Mg(q)2 (formulated as Mg(q)2(H20)2 [56531 -18-1]) and as Al(q)3 [2085-33-8] respectively. 2-Meth54-8-hydroxyquinohne [826-81-3] (6),... 

The powder contains 2inc oxide and magnesium oxide (36), and the Hquid contains an aqueous solution of an acryHc polycarboxyHc acid. Water settable cements have been formulated by inclusion of the soHd polyacid in the powdered base component. The set cement mainly consists of partially reacted and unreacted 2inc oxides in an amorphous polycarboxylate matrix (27,28). 

Miscellaneous Derivatives. Fimehc acid is used as an intermediate in some pharmaceuticals and in aroma chemicals ethylene brassylate is a synthetic musk (114). Salts of the diacids have shown utUity as surfactants and as corrosion inhibitors. The alkaline, ammonium, or organoamine salts of glutaric acid (115) or C-5—C-16 diacids (116) are useflil as noncorrosive components for antifreeze formulations, as are methylene azelaic acid and its alkah metal salt (117). Salts derived from C-21 diacids are used primarily as surfactants and find apphcation in detergents, fabric softeners, metal working fluids, and lubricants (118). The salts of the unsaturated C-20 diacid also exhibit anticorrosion properties, and the sodium salts of the branched C-20 diacids have the abUity to complex heavy metals from dilute aqueous solutions (88). 

Electroplated Metals and Alloys. The metals electroplated on a commercial scale from specially formulated aqueous solutions iaclude cadmium, chromium, cobalt, copper, gold, iadium, iron, lead, nickel, platinum-group metals, silver, tin, and ziac. Although it is possible to electroplate some metals, such as aluminum, from nonaqueous solutions as well as some from molten salt baths, these processes appear to have achieved Httie commercial significance. 

Product Requirements. When an enzyme is recovered from fermentation broth, it is usually present in an aqueous solution or processed to a dried state. Both types of preparation have to be formulated to comply with requirements appropriate to their final appHcation. 

In primer formulations for adhesive bonding of metals, the coupling agents that are most frequently used are those based on epoxy and amine functionalities. Aqueous solutions of aminosilanes have been successfully used for obtaining stable adhesive bonds between epoxy and steel [10] and epoxy and titanium [11,12], while epoxy functional silanes are preferable for applications involving aluminum substrates [13,14], A simple solution of % epoxy functional silane in water is currently used for field repairs of military aircraft [15] where phosphoric acid anodization would be extremely difficult to carry out, and performance is deemed quite acceptable. 

M = Al, Ga, In, Tl). The solution chemistry of Al in particular has been extensively investigated because of its industrial importance in water treatment plants, its use in many toiletry formulations, its possible implication in both Altzheimer s disease and the deleterious effects of acid rain, and the ubiquity of Al cooking utensils.For example, hydrated aluminium sulphate (10-30 gm ) can be added to turbid water supplies at pH 6.5-7.5 to flocculate the colloids, some 3 million tonnes per annum being used worldwide for this application alone. Likewise kilotonne amounts of A1(OH)2.5C1o.5 in concentrated (6m) aqueous solution are used in the manufacture of deodorants and antiperspirants. 

NH2OH can exist as 2 configurational isomers (cis and trans) and in numerous intermediate gauche conformations as shown in Fig. 11.7. In the crystalline form, H bonding appears to favour packing in the trans conformation. The N-O distance is 147 pm consistent with its formulation as a single bond. Above room temperature the compound decomposes (sometimes explosively) by internal oxidation-reduction reactions into a complex mixture of N2, NH3, N2O and H2O. Aqueous solutions are much more stable, particularly acid solutions in which the compound... 

Salts are obtained by direct neutralization of the acid with appropriate oxides, hydroxides, or carbonates. Sulfamic acid is a diy, non-volatile, non-hygroscopic, colourless, white, crystalline solid of considerable stability. It melts at 205°, begins to decompose at 210°, and at 260° rapidly gives a mixture of SO2, SO3, N2, H2O, etc. It is a strong acid (dissociation constant 1.01 x 10 at 25° solubility 25gper 100g H2O) and, because of its physical form and stability, is a convenient standard for acidimetry. Over 50000 tonnes are manufactured annually and its principal applications are in formulations for metal cleaners, scale removers, detergents and stabilizers for chlorine in aqueous solution. 

In aqueous solution the An02" ions (An = Pa Am) may be formed, at least in the absence of strongly coordinating ligands. They are linear cations like An02 + but are less persistent and, indeed, it is probable that Pa02" should be formulated as [PaO(OH)2]" " and [PaO(OH)]. Hydrolysis is extensive in aqueous solutions of Pa and colloidal hydroxo species are formed which readily lead to precipitation of... 

Recently, many investigators have extended the early observations that the ultraviolet spectra of - and y-hydroxypyridines resemble those of their A -methyl (not the 0-methyl) derivatives. This spectral resemblance is found both in aqueous solutions and in solutions of solvents with low dielectric constants, e.g., quinol-4-one in benzene, indicating that these compounds exist predominantly in the oxo form under all conditions. These data are summarized in Table I. In contrast, 4-hydroxyquinoline-3-carboxylic acid has been tentatively concluded to exist in the hydroxy form %- pjTid-2-one-4-carboxylic acid has also been formulated as a hydroxy compound, but this has been disputed. ... 

The neutral glasses are generally less resistant than the hard borosilicate type, but are more easily melted and shaped. They are formulated so that the pH of aqueous solutions is unaffected by contact with the glass, making it particularly suitable in pharmaceutical use for the storage of pH-sensitive drugs. 

NOTE In simple filming amine formulations ODA is the most widely employed ingredient. Formulations are typically available as 100% concentrated flakes, 2 to 5% strength aqueous solutions, or 5 to 10% strength emulsions. Solid ODA should be stored without exposure to air because it gradually reacts with carbon dioxide to form ODA carbonate, which is white and crumbly in composition. 

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