Propylene glycol combination with solvents

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. ... 

Ni et al. (2002) studied the stability of SarCNU (NSC 364432) in water, ethanol, propylene glycol (PG), Capmul PG, and DMSO, as well as their combinations over the temperature range of 25-660. The two cosolvents are an 80% PG 20% ethanol mixture (PE), and a semiaqueous vehicle (WPE) containing 50% water 40% PG 10% ethanol. The degradation mechanism in all the studied solvents is the same, and the stabilization by these vehicles follows the order of Capmul PG > Ethanol > PE > PE > PG > WPE > water, which is in agreement with their decreasing polarities. 

Table 1 list solvents and cosolvents used in parenteral products. Water for injection is the most common solvent but may be combined or substituted with a cosolvent to improve the solubility or stability of drugs.f The dielectric constant and solubility parameters are among the most common polarity indices used for solvent blending.f Ethanol and propylene glycol are used either alone or in combination with other... 

Peel-off masks are applied in a uniform layer on the skin and upon drying and removal produce a sensation of skin tightness and cleansing action. Peel-off masks are marketed to consumers with normal, oily, combination, and acne-prone skin types. These masks are believed to perform the functions of skin exfoliation, hydration, and purification. They are based on plasticized polyvinyl alcohol. Hydrophilic emollients (e.g., ethoxylated fatty acid or alcohol derivatives, dimethicone copolyol) and humectants (e.g., glycerin, propylene glycol, sorbitol) are added to prevent moisture loss and cracking of polyvinyl alcohol film. Solvents... 

An example of a typical batch preparation of a polyester is one where 1.2 moles of propylene glycol, 0.67 mole of maleic anhydride, and 0.33 mole of phthalic anhydride are combined. Propylene glycol is used in excess to compensate for loss during the reaction. The condensation at 150-200 °C lasts for 6-16 hours, with constant removal of water, the byproduct. An aromatic solvent, like toluene or xylene, is often added to the reaction mixtures to facilitate water removal by azeotropic distillation. Esterification catalysts, like toluene sulfonic acid, reduce the reaction time. In addition. 

The combined high solvency of propylene glycol phenyl ether (PPh) for acrylic and vinyl acetate latexes and the solvent s low water solubility provides excellent coalescent efficiency for these latexes. Comparison of PPh and another coalescent solvent Texanol (2,2,4-trimethyl-1,3-pentanedioI monoisobutyrate) in a study with several latexes found PPh to be superior [4]. 

Cosmetic and personal care products use glycol ethers as solvents and coupling aids. Dipropylene glycol methyl ether is often used in combination with propylene glycol in cosmetics. Ethylene glycol phenyl ether at a 1.0% level acts as a preservative in personal care products. 

A wide variety of monovinyl and divinyl ethers are commercially available for this application, which allows the formulator greater latitude. For example, triethylene glycol divinyl ether [76-12-8] (DVE-3) and 1,4-cyclohexanedimethanol divinyl ether [17351-75-6] (CHVE) can be combined as reactive diluents, with each contributing quite different properties to the subsequently cured coating. CHVE offers hard brittle films, whereas DVE-3 produces films that have greater flexibility. DVE-3 is also a good solvent for the photoinitiator. More recently, the propenyl ether of propylene carbonate [130221-78-2] (PEPC) has been commercialized and specifically developed as a solubilizer for such initiators (68). Combinations of both divinyl ethers offer superior coatings that have controllable levels of flexibility, hardness, and solvent resistance (69). Their trade names are Rapi-Cure DVE-3, CHVE, PEPC, etc. 

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