Sucrose relaxation

Other studies indicate that sucrose does not cause hyperactivity. Carbohydrate ingestion increases levels of serotonin (5-hydroxytryptamine), a brain neurotransmitter that promotes relaxation and sleep. Dietary sucrose should theoretically have a calming effect and reduce activity, manifestations which have been observed in case studies (63). To date, clinical investigations have failed to show a significant connection between sucrose consumption and aggressive or dismptive behavior (66). 

Some simplified assumptions for extracting interproton relaxation-contributions from a single set of nonselective relaxation-rates have been made for a tetrachlorotetra-0-mesyl-ga/ac(o-sucrose derivative (43). By con-... 

The time t that must elapse before a supersaturated solution reaches a quasi-stationary concentration In dilute aqueous solutions, t is typically around 10 seconds, but for some solutes this period has proven to be much greater. For example, Dunning found that the relaxation period for concentrated sucrose solutions is about 100 hours. See Biomineralization... 

Aso et al. (40) examined the molecular mobility of sucrose and polyvinylpyrrolidone in 1 1 lyophilized mixtures by measuring the spin-lattice relaxation times (7)) of individual carbon atoms by NMR for systems containing residual moisture at varying levels. 7) of the pyrrolidone ring carbon increased with residual moisture for lyophilized PVP alone. However, the mobility of these carbons did not increase with residual moisture when PYP was colyophilized with sucrose. Similarly, the mobility of sucrose did not increase with water activity as much in sucrose/PVP mixtures as much as in sucrose alone. Inhibition of sucrose crystallization by PVP in the presence of water appears to be linked to the effect of PVP on the molecular mobility of sucrose. 

Aso Y, Yoshioka S, Zhang J, Zografi G. Effect of water on the molecular mobility of sucrose and polyvinylpyrrolidone) in a colyophilized formulation as measured by 13C NMR relaxation time. Chem Pharm Bull 2002 50 820-826. 

Kett et al. [1.162] studied Tg in freeze-dried formulations containing sucrose as a function of relative humidity and temperature during storage by TMDSC and ther-mogravimetric analysis. Craig et al. [1.163] found it helpful to asses the relaxation behavior of freeze-dried amorphous lactose by MTDSC. Relaxation times were calculated from measurements of Tg, and the magnitude of the relaxation endotherm. Scannnig was performed at 2°C/min with a modulation amplitude of 0.3 °C and a period of 60 s. 

S. B. Engelsen, C. Herve du Penhoat, and S. Perez, Molecular relaxation of sucrose in aqueous solution How a nanosecond molecular dynamics helps to reconcile NMR data, J. Phys. Chem., 99 (1995) 13334-13351. 

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