Aqueous hydroxypropyl cellulose

Aqueous hydroxypropyl cellulose is another type of rod-like material reported to undergo phase separation with heating (4). [Pg.267]

Aqueous hydroxypropyl cellulose solutions amplification vs. wave number, 275,277/ apparent diffusivity vs. temperature, 275,277/ calculation of maximum scattered intensity, 278... [Pg.354]

Aqueous hydroxypropyl cellulose solutions have optimum stability when the pH is maintained at 6.0-8.0, and also when the solution is protected from light, heat, and the action of microorganisms. [Pg.338]

Werbowyj, R.S. Gray, D.G. Liquid crystalline structure in aqueous hydroxypropyl cellulose solutions. Molec. Crystals Liquid Crystals 1976, 34 (4), 97-103. [Pg.2672]

Nishio, Y. Chiba, R. Miyashita, Y. Oshima, K. Miyajima, T. Kimura, N. Suzuki, H. Salt addition effects on mesophase structure and optical properties of aqueous hydroxypropyl cellulose solutions. Polym. J. 2002, 34 (3), 149-157. [Pg.2674]

Chiral disubstituted PEDOTs have recently been prepared for the first time via transetherification of 3,4-dimethoxythiophene monomers with chiral glycols followed by potentiodynamic oxidation.174 An alternative approach to optically active PEDOTs has also been recently described, which involves the electrochemical polymerization of the EDOT monomer in aqueous hydroxypropyl cellulose (HPC) as a polymer lyotropic liquid crystal to give a chiral PEDOT/HPC hybrid.175 The PEDOT prepared in this chiral nematic liquid crystal exhibited optically active electrochromism in that it could be electrochemically switched between a dark blue reduced state and a sky blue oxidized form that exhibited a different CD spectrum. [Pg.225]

M. Ito, Y. Teramoto, and Y. Nishio, Electrooptical behavior of aqueous (hydroxypropyl)cellulose liquid crystals containing imidazolium salts. Biomacromolecules 13, 565-569 (2012). [Pg.391]

Chanzy H, Peguy A, Chaunis S, Monzie P (1980) Oriented cellulose films and fibers from a mesophase system. J Polym Sci Polym Phys Ed 18(5) 1137-1144 Charlet G, Gray DG (1987) Solid cholesteric films cast from aqueous (hydroxypropyl)cellulose. Macromolecules 20(l) 33-38... [Pg.364]

Watanabe J, Nagase T (1988) ThermoLopic polypeptides. 5. Temperature dependence of cholesteric pitches exhibiting a cholesteric sense inversion. Macromolecules 21(1) 171-175 Wenzel RN (1936) Resistance of solid surfaces to wetting by water. Ltd Eng Chem 28(8) 988-994 Werbowyj RS, Gray DG (1976) Liquid crystalline structure in aqueous hydroxypropyl cellulose solutions. Mol Cryst Liq Cryst 34(4) 97-103... [Pg.367]

Charlet G, Gray DG. Solid cholesteric films cast from aqueous (hydroxypropyl) cellulose. Macromolecules 1987 20 33-8. [Pg.51]

Commonly used cellulose derivatives include hydroxypropyl cellulose (HPC), car-boxymethylcellulose, and hydroxyethyl cellulose (HEC). The choice amongst these cellulose derivatives is primarily based on the type of formulation (aqueous or... [Pg.207]

Treatment of acne vulgaris Erythromycin Emgel Hydroxypropyl cellulose Aqueous... [Pg.223]

Hydroxy propyl methyl cellulose (HPMC).35 HPMC is a partly O-methylated and 0-(2-hydroxypropylated) cellulose available in several grades that vary in viscosity and extent of substitution. It is used widely in pharmaceutical formulations, especially in oral products, as a tablet binder, in film coating, and as controlled release matrix. Soluble in cold water, it forms a viscous colloidal solution. For a 2% aqueous solution (20°C), viscosity can range from 2.4 to 120,000 mPa-s. High-viscosity grades can be used to retard the release of water-soluble drugs from a matrix. [Pg.161]

Liquid-crystalline solutions and melts of cellulosic polymers are often colored due to the selective reflection of visible fight, originating from the cholesteric helical periodicity. As a typical example, hydroxypropyl cellulose (HPC) is known to exhibit this optical property in aqueous solutions at polymer concentrations of 50-70 wt%. The aqueous solution system is also known to show an LCST-type of phase diagram and therefore becomes turbid at an elevated temperature [184]. [Pg.135]

Frohoff-Hulsmann, M.A. Schmitz, A. Lippold, B.C. Aqueous ethyl cellulose dispersions containing plasticizers of different water solubility and hydroxypropyl methyl-cellulose as coating material for diffusion pellets. I. Drug release rates from coated pellets. Int. J. Pharm. 1999, 177, 69-82. [Pg.1744]

Fukumori, Y. Ichikawa, H. Jono, K. Fukuda, T. Osako, Y. Effect of additives on agglomeration in aqueous coating with hydroxypropyl cellulose. Chem. Pharm. Bull. 1993, 41 (4), 725-730. [Pg.1778]

Aqueous solutions of hydroxypropyl cellulose are stable at pH 6.0-8.0, with the viscosity of solutions being relatively unaffected. However, at low pH aqueous solutions may undergo acid hydrolysis, resulting in chain scission and hence... [Pg.338]

Increasing temperature causes the viscosity of aqueous solutions to decrease gradually until the viscosity drops suddenly at about 45°C owing to the limited solubility of hydroxypropyl cellulose. However, this process is reversible and on cooling the original viscosity is restored. [Pg.338]

Ultraviolet light will also degrade hydroxypropyl cellulose and aqueous solutions may therefore decrease slightly in viscosity if exposed to light for several months. [Pg.338]

Table VI Compatibility of hydroxypropyl cellulose (N/sso HPQ with inorganic salts in aqueous solutions.

Lindberg NO. Water vapour transmission through free films of hydroxypropyl cellulose. Acta Pharm Suec 1971 8 541-548. Banker G, Peck G, Williams E, et al. Evaluation of hydroxypro-pylcellulose and hydroxypropylmethylcellulose as aqueous based film coatings. Drug Dev Ind Pharm 1981 7 693-716. [Pg.340]

The addition of sodium chloride to aqueous spray-coating solutions containing hydroxypropyl cellulose or hypromellose suppresses the agglomeration of crystalline cellulose particles. Sodium chloride can also be used to modify drug release from gels and from emulsions.It can be used to control micelle size, and to adjust the viscosity of polymer dispersions by altering the ionic character of a formula-... [Pg.671]

Aqueous sodium chloride solutions are corrosive to iron. They also react to form precipitates with silver, lead, and mercury salts. Strong oxidizing agents liberate chlorine from acidified solutions of sodium chloride. The solubility of the antimicrobial preservative methylparaben is decreased in aqueous sodium chloride solutions and the viscosity of carbomer gels and solutions of hydroxyethyl cellulose or hydroxypropyl cellulose is reduced by the addition of sodium chloride. [Pg.673]

Discovery of the formation of liquid crystalline solutions by cellulosics in the mid-1970s has resulted in attempts to develop new cellulosics products with properties superior to those of conventional cellulosic. Following the first observation of mesophases formed in aqueous solutions of hydroxypropyl cellulose (HPC), a variety of other cellulose derivatives have been reported to form liquid crystals. Liquid crystalline solutions of cellulose and its derivatives provide a potential route to high-modulus and high-tenacity cellulosic fibers, films, and other high-performance products. [Pg.2663]

Nishio, Y. Yamane, Y. Takahashi, T. Morphological studies of liquid-crystalline cellulose derivatives. II. Hydroxypropyl cellulose films prepared from liquid-crystalline aqueous solutions. J. Polym. Sci. Polym. Phys. Ed. 1985, 23 (5), 1053-1064. [Pg.2673]

Chiba, R. Nishio, Y. Miyashita, Y. Electroopti-cal behavior of liquid-crystalline (hydroxypropyl)-cellulose/inorganic salt aqueous solutions. Macromolecules 2003, 36 (5), 1706-1712. [Pg.2674]

The flow through an abrupt contraction " or a step stenosis was demonstrated. The flow of liquid crystalline hydroxypropyl cellulose aqueous solutions, where polymer was flowing through an abrupt contraction, was imaged by pulsed field gradient NMR techniques. Flow velocity was determined in the case of the flow through step stenosis. ... [Pg.440]