Sorbitol interaction

Reaction of olefin oxides (epoxides) to produce poly(oxyalkylene) ether derivatives is the etherification of polyols of greatest commercial importance. Epoxides used include ethylene oxide, propylene oxide, and epichl orohydrin. The products of oxyalkylation have the same number of hydroxyl groups per mole as the starting polyol. Examples include the poly(oxypropylene) ethers of sorbitol (130) and lactitol (131), usually formed in the presence of an alkaline catalyst such as potassium hydroxide. Reaction of epichl orohydrin and isosorbide leads to the bisglycidyl ether (132). A polysubstituted carboxyethyl ether of mannitol has been obtained by the interaction of mannitol with acrylonitrile followed by hydrolysis of the intermediate cyanoethyl ether (133). 

Table II shows the average end-to-end distance over 20 ps for mannitol and sorbitol in vacuuo and in solution of an argon-like (L-J) solvent and SPC/E water. The average lengths all indicate sickle shapes, except for mannitol in water which is fully extended. This points to a specific solute-solvent interaction between mannitol and water, not just an unspecific solvent effect that is not present in solvent other than water. The model non-aqueous solvent is very artificial, but it should represent the main features of the class of non-polar, spherically symmetric solvents.

Recent 620.6 MHz nmr results on sorbitol and mannitol (9) confirm that sorbitol rotates more freely in water than mannitol. This suggests that there is less solute-solvent interaction in sorbitol. Calorimetric results (J ) predict that sorbitol and mannitol should have hydration behavior similar to that described above. Those workers, however, referred to structure breaking properties, even though no structural data was obtained. 

Sodium Polystyrene Sulfonate (Kayexalate) [Potassium Removing Resin] Uses Rx of T K Action NaVK" ion-exchange resin Dose Adults. 15-60 g PO or 30-60 g PR q6h based on serum Peds. 1 g/kg/dose PO or PR q6h based on serum (given w/ agent, eg, sorbitol, to promote movement through the bowel) Caution [C, M] Contra T Na" Disp Powder, susp SE T Na", -i Na retention, GI upset, fecal impaction Interactions T Risk of systemic alkalosis W/ Ca- or Mg-containing antacids EMS Monitor ECG for h5 pokalemia (flattened T waves) OD Not systemically absorbed but may cause h5 pokalemia and the associated effects (muscle weakness, confusion) and bowel obstruction s5rmpto-matic and supportive... 

Similar to the mixtures of methyl ct-D-gluco-pyranoside and sucrose, mixtures of sucrose and D-sorbitol closely fit the competitive interaction curve (Figure 10). Response to the mixture gave a less-than-additive effect at high concentrations. The maximum response for the mixture did not exceed the maximum response evoked by sucrose alone. 

Figure 10. Concentration-response curve of sucrose in the presence of v-sorhitol [sorb]. The solid lines are the theoretical curves obtained from the equation describing the competitive interaction of two substances with a single receptor site (see Figure 9). Data points for sucrose alone (%), sorbitol alone (Aj sucrose 4- 0.03 M [sorb] ( ), sucrose + 0.1 M [sorb] fM), sucrose + 0.3 M [sorb] (O).

This effect of polyhydroxyl compounds may not be quite as simple as it has been described, as the structure of the polyhydroxyl compound may play some part in effective stabilization of enzymes in wet systems. Thus Fujita et al, (20) reported that inositol was more effective than sorbitol in stabilizing lysozyme in aqueous solutions. Both compounds contain six hydroxyl groups, but inositol is cyclic in structure whereas sorbitol is linear, Fig 10. The interaction of polyhydroxyl compounds with water promotes a change in the molecular structure of water. Inositol was reported to have a larger structure-making effect than sorbitol, which accounted for the greater stabilization effect of this compound. 

The subtle differences between sugar molecules which cause such dramatic effects (Le. Dulcitol verses sorbitol) are possibly caused by adverse interactions either with water or the amino acids of the protein. It is possible that under certain conditions the position of hydroxyl groups causes strong binding of water and leads to confirma-tional distortion of the protein rather than stabilization. Monsan and Combes (13) have suggested that this is due to excessive binding to the stabilizer thus disrupting the protein surface/water interactions. As yet we have no evidence to further elucidate this theory. 

Kubicki, J.D. and Heaney, P.J., Modeling Interactions of Aqueous Silica and Sorbitol Complexation, Polymerization and Association, paper presented at the Goldschmidt Conference, Homestead, VA, 2001. 

Some typical structural templates embedded with the thiazoHdine frame have been reported as potent inhibitors of aldose reductase (AR), an enzyme in the polyol pathway responsible for the conversion of glucose to sorbitol. In this, the accumulation of sorbitol has been attributed to causing cataracts, neuropathy, and retinopathy in diabetic cases [ 157,158]. The planar hydrophobic (aromatic) regions and propensity to charge transfer interactions have been... 

Fig. 20 Interactive mixtures with sorbitol as a carrier. Sorbitol plus 16% micronized etilefrine HCl, part of the granule (A), sectional view from left showing the fine sorbitol needles and the micronized particles of etilefrine (B). Pure sorbitol instant (C), sorbitol plus 16% propranolol (D).

A stable floe may also be produced by dispersing insoluble particles in a turbid or hazy vehicle consisting of finely dispersed or emulsified semipolar, liquid droplets, which cause the droplets to be adsorbed on the surface of the insoluble drug particles, resulting in a stable floe. Turbid aqueous vehicles have been prepared by the interaction of non-ionic surfactants and preservatives. The concentration of surfactant and preservative required for haze formation may be reduced by the addition of small amounts of sorbitol to the vehicle. 

Physical effects caused by polyethylene glycol bases include softening and liquefaction in mixtures with phenol, tannic acid, and salicylic acid. Discoloration of sulfonamides and dithranol can also occur and sorbitol may be precipitated from mixtures. Plastics, such as polyethylene, phenolformaldehyde, polyvinyl chloride, and cellulose-ester membranes (in filters) may be softened or dissolved by polyethylene glycols. Migration of polyethylene glycol can occur from tablet film coatings, leading to interaction with core components. 

Blanchard J, Fink WT, Duffy JP. Effect of sorbitol on Interaction of phenolic preservatives with polysorbate 80. J Pharm Sci 1977 66 1470-1473. 

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