Sorbitol types

The apparent acid strength of boric acid is increased both by strong electrolytes that modify the stmcture and activity of the solvent water and by reagents that form complexes with B(OH) 4 and/or polyborate anions. More than one mechanism may be operative when salts of metal ions are involved. In the presence of excess calcium chloride the strength of boric acid becomes comparable to that of carboxyUc acids, and such solutions maybe titrated using strong base to a sharp phenolphthalein end point. Normally titrations of boric acid are carried out following addition of mannitol or sorbitol, which form stable chelate complexes with B(OH) 4 in a manner typical of polyhydroxy compounds. EquiUbria of the type ... 

An oral dental riase geaeraHy coasists of water, alcohol, a humectant, an emulsifier, flavor, color, and an active agent. Water is the primary vehicle. The alcohol provides bite and is also a formulation aid. The humectant improves the feel ia the mouth and also prevents locking of the cap to the container between uses glycerin or noncrystaUiziag sorbitol may be satisfactory. The emulsifier is a nonionic type, for example, a polyoxyethylene—polyoxypropylene block copolymer or a polyoxyethylene sorbitan fatty acid ester. Flavors are generally a type of mint or cinnamon. Colors are FD C or D C. 

Different preparative procedures have been shown to yield protein fractions which are able to catalyze different types of reactions with respect to their requirement of either NAD or NADP as coenzymes [cf. Eqs. (19), (20), and (21)]. In sera of mice poisoned by carbon tetrachloride we found polyol dehydrogenases catalyzing the oxidation of the following polyols (a) with NAD sorbitol, ribitol, mannitol (b) with NADP sorbitol, ribitol. Erythritol and mt/o-inositol were not attacked at all. Figures 8 and 9 show the results of these determinations performed at pH 9.6. In the NAD system sorbitol and ribitol are oxidized at exactly the same rate, while in the NADP system ribitol does not reach the rate of sorbitol. The ratio NAD NADP for sorbitol is calculated to be 4.20 and for ribitol 5.50. Mannitol is oxidized at 23% of the rate of sorbitol. 

There are several examples of one-pot reactions with bifunctional catalysts. Thus, using a bifunctional Ru/HY catalyst, water solutions of corn starch (25 wt.%) have been hydrolyzed on acidic sites of the Y-type zeolite, and glucose formed transiently was hydrogenated on ruthenium to a mixture of sorbitol (96%), mannitol (1%), and xylitol (2%) [68]. Similarly a one-pot process for the hydrolysis and hydrogenation of inulin to sorbitol and mannitol has been achieved with Ru/C catalysts where the carbon support was preoxidized to generate acidic sites [69]. Ribeiro and Schuchardt [70] have succeeded in converting fructose into furan-2,5-dicarboxylic acid with 99% selectivity at 72% conversion in a one-pot reaction... 

Sorbitol. Sorbitol is the sugar alcohol obtained by reduction of glucose and it can be dehydrated to either isosorbide or to 1,4- and 2,5-sorbitan in acid or base catalyzed processes, respectively. Using sulfonic acid functionalized MCM-41 type materials lauric acid esters of isosorbide can be achieved quite selectively starting from sorbitol (>95% selectivity towards isosorbide dilaurate at 33% lauric acid conversion) in a dehydration-esterification... 

Type of Sorbitol Vendor Vendor Particle Size Specifications Lot... 

Type of Sorbitol Lot KF Titration Value (%) Total Volatile Content by TG (%) DSC peak maximum (°C)... 

Type of Sorbitol Lot Mean Particle Size (pm) Particle Size 95% Less Than (pm) Surface Area (m /g)... 

The classification system introduced by Carr [29,30] was used to evaluate the flow properties of the sorbitol powders. In Carr s system, a flowable powder is defined as free flowing and will tend to flow steadily and consistently. This is to be contrasted with a floodable powder, which will exhibit an unstable, discontinuous, and gushing type of flow. The parameters in Carr s system include the angle of repose, angle of spatula, compressibility, cohesion, and dispersibility. Based on these parameters, flowability and floodability indices are calculated to determine the handling properties of bulk solids. 

In view of the highly unusual nature of these results and the lack of a routine method for transport measurements unambiguously establishing that rapid transport was indeed a real manifestation of the system, our studies on rapid polymer transport remained unreported in detail. However, in a recent article 46> we have demonstrated that rapid polymer transport actually occurs in these systems due to the formation of ordered macroscopic structures which move rapidly. This rapid transport has been shown to be not the result of bulk convection since normal diffusional kinetics was observed for solvent markers such as [l4C]sorbitol. The striking feature of this new type of transport process is that it is accompanied by ordered structured flows in the... 

---