Amorphous solid solubility

Di-(carboxymethylthio).p-carbamidophenylarsine thus prepared was obtained as a white amorphous solid, soluble in dilute alkali. It contained about 19.85% of arsenic as compared with the calculated amount of 19.09%. 

Properties of panal (Nakamura etal., 1988a). Purified panal is a colorless, amorphous solid, soluble in alcohols, water, ethyl acetate, and chloroform. The absorption spectrum (Fig. 9.3) shows a single peak (A.max 217nm, e 15,300). Optical rotation [a]D —17° (c 0.9, methanol). Mass spectrometry and NMR analysis showed that panal is a sesquiterpene aldehyde, C15H18O5 (Mr 278.30), with the structure shown below. 

Properties White, amorphous solid. Soluble in water. 

Bariiun Monohydroxid—BaiHOi—170.8—is prepared by the action of H 0 on BaO. It is a white, amorphous solid, soluble in HiO. Its aqueous solution, baryta water, is alkaline, and absorbs COj, with formation of a white deposit of BaCOs. 

Dihydrostreptomycin sesquisulfate [5490-27-7] M 461.4, m 250 (dec), 255-265 (dec), [a]p -92.4 (c 1, H2O), pKgsJd)-- 9.5 (NMe), pKes,(2,3) 13.4 (guanidino). It crystallises from H2O with MeOH, -BuOH or methyl ethyl ketone. The crystals are not hygroscopic like the amorphous powder, however both forms are soluble in H2O but the amorphous solid is about 10 times more soluble than the crystals. The free base also crystallises from H20-Me2C0 and has [a]p -92° (aqueous solution pH 7.0). [Solomons and Regina Science 109 515 7949 Wolf et al. Science 109 515 7949 McGilveray and Rinehart J Am Chem Soc 87 4003 1956]. 

The dried product is a reddish brown, amorphous solid presenting a glistening surface upon fracture. The dry product is somewhat hygroscopic and is freely soluble in water to give a stable solution. The following paragraph gives an alternative preparation. 

Commonly an amorphous solid may have solubility in both aqueous and DMSO that is over 100 hmes higher than any of the crystalline forms. An amorphous solid can be inadvertently created from a crystalline material, e.g. by heating a crystalline hydrate or solvate for a short time period below its melhng point in a drying pistol. 

A synthesis of comblike organoboron polymer/boron stabilized imidoanion hybrids was examined via reactions of poly(organoboron halides) with 1-hexylamine and oligo(ethylene oxide) monomethyl ether and subsequent neutralization with lithium hydride (scheme 8). The obtained polymers (10) were amorphous soft solids soluble in common organic solvents such as methanol, THF, and chloroform. In the nB-NMR spectra (Fig. 11), neutralization of the iminoborane unit with lithium hydride... 

The most thermodynamically stable polymorph is usually desired for the API product to maximize its formulated stability. Selecting the thermodynamically stable form does however, have the disadvantage of minimizing the solubility and bioavailability. Although less desirable and common it is feasible to use an amorphous solid form of the API if it can be demonstrated that it is stable in the formulation. 

White amorphous solid deliquescent density 4.32 g/cm melts at 315°C dissolves slowly in water but is very soluble (230 g/lOOg at 20°C) also soluble in alcohol. 

Addition of a soluble Zr(IV) salt to phosphoric acid results in the precipitation of a gelatinous amorphous solid. The stoichiometric crystalline zirconium phosphate can be prepared by refluxing zirconium phosphate-gel in concentrated phosphoric acid [5]. The procedures for synthesis of zirconium phosphate have been described in detail elsewhere [6]. 

In general, hydrated borates of heavy metals are prepared by mixing aqueous solutions or suspensions of the metal oxides, sulfates, or halides and boric acid or alkali metal borates such as borax. The precipitates formed from basic solutions are often sparingly-soluble amorphous solids having variable compositions. Crystalline products are generally obtained from slightly acidic solutions. 

By rapidly cooling the fluid mixture it is possible to minimise the readjustment of the equilibrium and to attain a solid condition in which tire original proportions of the mixture are approximately retained in the solid state tire allotropic change is so very slow as to allow careful and fairly prolonged examination of the mixture. It is then found that, the normal mobile liquid constituent (S ) has given rise to crystalline sulphur, soluble in carbon disulphide, whereas the dark-coloured viscous constituent (S ) has produced an amorphous solid, insoluble in this solvent4 (see also p. 10). A rough analysis of molten sulphur in... 

When a solution of thiocyanogen in carbon disulphide is cooled to —70° C., the thiocyanogen is obtained in cruciform aggregates of almost colourless crystals, melting at —2° to —3° C. On warming to ordinary temperatures the thiocyanogen becomes reddish-brown in colour and more viscous finally a brick-red amorphous solid is obtained. Thiocyanogen is very readily soluble in ethyl alcohol and ether, slowly soluble in carbon disulphide and carbon tetrachloride.5... 

Docusate Calcium. Dioctyl calcium sulfosuccinate [128-49-4] (calcium salt of l,4-bis(2-ethylhexyl)ester butanedioic acid) (11) is a white amorphous solid having the characteristic odor of octyl alcohol. It is very slightly soluble in water, and very soluble in alcohol, polyethylene glycol 400, and com oil. It may be prepared direcdy from dioctyl sodium sulfo succinate dissolved in 2-propanol, by reaction with a methanolic solution of calcium chloride. 

The aging processes leading to the changes of the properties of samples overtime (such as solidification of liquids, decrease in solubility, increase in evaporation temperature, changes in the composition of the fragments in the mass-spectra, crystallization of amorphous solids) have become wellknown. These processes, very characteristic also for the hydroxides, are caused by aggregation or polymerization and also by condensation of oligomeric molecules. 

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