Thermodynamics of liquid-crystalline solutions of hydroxypropyl cellulose in water and ethanol

Phase diagrams and rheological properties of cellulose ether solutions in magnetic field

“…4 displays the phase diagram measured for the HPC-water system. This diagram is largely consistent with the phase diagrams described for this system [27][28][29][30][31][32][33][34][35][36][37][38][39]. (1 -Refers to colorless solutions and 2 -refers to blue solutions, which is typical of cholesterol LC solutions.)…”

“…Molecules of cellulose and cellulose derivatives are characterized by a rigid helical conformation and, hence, they are capable of ordering and formation of cholesteric liquid crystals in concentrated solutions. Many studies were devoted to phase equilibrium in the HPC-water system, and the low critical solution temperature values were reported in a number of papers [27][28][29][30][31][32][33][34][35][36][37][38][39] a magnetic field on the liquid crystal structure was studied by Meuer [40], de Gennes [41]. The authors considered such a field distortion of the cholesteric structure and found out that the transition to complete nematic order occursed at the critical field strength.…”

Application of Interferometry to Analysis of Polymer-Polymer and Polymer-Solvent Interactions

“…28. A set of phase diagrams for the HPC-water system according to (Fischer et al, 1995;Guido, 1995;Larez et al, 1995;Vshivkov et al, 2007) Although the diagrams follow the general pattern, the positions of phase equilibrium lines differ appreciably; moreover, it is unclear which is the character of phase separation at temperatures above 40-45 o C. It is known that elevated temperatures solutions experience reversible gel-formation; however, the mechanism controlling formation of the physical network remains vague up to now. Two mechanisms of this process are discussed in the literature: phase decomposition of the liquid-liquid type and formation of the HPC .…”

Low-Viscosity Hydroxypropylcellulose (HPC) Grades SL and SSL: Versatile Pharmaceutical Polymers for Dissolution Enhancement, Controlled Release, and Pharmaceutical Processing

“…Therefore, HPC depicts organic as well as water solubility and hence is suitable for solvent methods to manufacture SDs (19). In addition, it also has lower critical solution temperature of 45°C due to the presence of both hydrophilic and hydrophobic groups and forms liquid crystals and many other mesophases in water, depending upon concentration (20)(21)(22). Such liquid crystalline phases may form gel-like layers associated with hydrated HPC formulation to control the release of highly water-soluble drugs (23).…”