Propylene glycol as solvent

Morizono T, Johnstone BM. Ototoxicity of chloramphenicol ear drops with propylene glycol as solvent. Med J Aust 1975 2 634-638. 

For free-running dye jets the viscosity of the liquid solvent must be sufficiently large to ensure the laminar flow necessary for high optical quality of the gain zone. Most jet-stream dye lasers use ethylene glycol or propylene glycol as solvents. Since these alcohols decrease the quantum efficiency... 

For free-running dye jets the viscosity of the liquid solvent must be sufficiently large to ensure the laminar flow necessary for high optical quality of the gain zone. Most jet-stream dye lasers use ethylene glycol or propylene glycol as solvents. Since these alcohols decrease the quantum efficiency of several dyes and also do not have optimiun thermal properties, the use of water-based dye solutions with viscosity-raising additives can improve the power efficiency and frequency stability of jet-stream cw dye lasers [5.193]. Output powers of more than SOW have been reported for cw dye lasers [5.194],... 

STEVENS j R and jacobsson p, A comparison of acetone and poly(propylene glycol) as solvents for lithium triflate and lithium perchlorate , Can J Chem, 1991,69,1980-1984... 

Paper chromatography using Whatman No. 1 paper was once used to determine the homogeneity of halcinonide. 60 Twenty percent formamide in methanol comprises one stationary phase and methylisobutyl ketone-formamide (20 1) is the mobile phase. A second solvent system uses 25% propylene glycol-chloroform as the stationary phase and toluene saturated with propylene glycol as the mobile phase. 

Hemolysis has been reported after the administration of etomidate (18). It may be related to the use of propylene glycol as a solvent (19,20). 

In topical applications, propylene carbonate has been used in combination with propylene glycol as a solvent for corticosteroids. The corticosteroid is dissolved in the solvent mixture to vield microdroplets that can then be dispersed in petrolatum. Propylene carbonate has been used as a dispensing solvent in topical preparations. ... 

Since we are considering the hydrolysis of dmgs it might seem that an obvious way to reduce the breakdown would be to replace some or all of the water in the system with a solvent such as alcohol or propylene glycol. As we will see in this section, however, this is effective only in certain systems and in others it can, in fact, increase the rate of breakdown. The equation that allows us to predict the effect of the solvent on the hydrolysis rate is... 

The Food and Drug Administration (FDA) has classified propylene glycol as an additive that is generally recognized as safe for use in food. It is used to absorb extra water and maintain moisture in certain medicines, cosmetics, or food products. It is a solvent tor food colors and flavors. 

Solvents are usually classified by the functional groups of the molecule. The most used classes are listed in Table 3.1 and in Appendix 2.1. Each solvent of a class has properties similar to other members of the class. Solvents transformed the ability of technology, and conservators, to manipulate materials. However, widespread use has been shown to have many deleterious side-effects such as toxicity, flammability, damage to water and air quality, effect on the ozone layer, cost, etc. New solvents are being introduced to reduce these effects, e.g. the use of siloxane-based fluids (Cull and Swanson, 2001) or propylene glycol-derived solvents replacing ethylene glycol-derived ones. 

Saleh et al. [306] have studied the solubility of diazepam in sodium salicylate solution as a potential parenteral formulation. At present diazepam, which is practically insoluble in water, is formulated with propylene glycol as the main solvent component but undesirable clinical effects following intramuscular and intravenous injection have been attributed to the propylene glycol. The solubility of diazepam increases significantly at concentrations of salicylate greater than 15 to 20%. At 30%, the solubility has increased to over 16 mg ml (Fig. 6.46). The... 

In addition to these forms of water, several other official aqueous vehicles can be used. These are isotonic injections that can be sterilised, eg, sodium chloride. Ringer s, dextrose, dextrose and sodium chloride, and lactated Ringer s. Addition of water-miscible solvents such as ethanol or propylene glycol increases solubiUty and stabiUty. 

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