Cellulose hydroxypropylcellulose

Acrylates copolymer Aluminum distearate Aluminum palmitate Attapulgite Capryl hydroxyethyl imidazoline EO/PO ethylenediamine block copolymer Ethylene/MA copolymer Hydroxyethylcellulose Isopropyl glycidyl ether Magnesium aluminum silicate Montmorillonite PEG-4 laurate PEG-12 laurate PEG-5M PEG-9M PEG-23M PEG-45M PEG-20 oleate PEG-4 stearate PEG-20 stearate Polyethylene wax PVP Silica, fumed Sodium polyacrylate Stearamide Tall oil hydroxyethyl imidazoline Xanthan gum thickener, paints/coatings Methyl hydroxyethylcellulose thickener, paints emulsion Ethyl hydroxyethyl cellulose Hydroxypropylcellulose thickener, paper... 

Since the hydroxyl groups in cellulose are reactive and can be easily functionalized, cellulose has been made into a large number of derivatives in the form of ethers, esters, and acetals, such as methyl cellulose, hydroxypropylcellulose, hydroxypropyl methyl cellulose, and carboxymethyl cellulose. These cellulose derivatives are soluble in a variety of solvents and can be easily processed into various forms, such as... 

Properties. Hydroxypropylcellulose [9004-64-2] (HPC) is a thermoplastic, nonionic cellulose ether that is soluble in water and in many organic solvents. HPC combines organic solvent solubiUty, thermoplasticity, and surface activity with the aqueous thickening and stabilising properties characteristic of other water-soluble ceUulosic polymers described herein. Like the methylceUuloses, HPC exhibits a low critical solution temperature in water. 

An erodible insert developed as a potential ocular drug-delivery system is marketed as a prescription drug for the lubricant properties of the polymer base. Lacrisert is a sterile ophthalmic insert used in the treatment of moderate to severe dry eye syndrome and is usually recommended for patients unable to obtain symptomatic relief with artificial tear solutions. The insert is composed of 5 mg of hydroxypropylcellulose in a rod-shaped form about 1.27 mm diameter by about 3.5 mm long. No preservative is used, since it is essentially anhydrous. The quite rigid cellulose rod is placed in the lower conjunctival sac and first imbibes water from the tears and after several hours forms a... 

Hydroxypropylcellulose (HPC) is a thermoplastic nonionic cellulose ester that is soluble in both water and a number of organic liquids. It is synthesized through reaction of the basic cellulose slurried with propylene oxide. 

These stabilizers are added to the formulation in order to stabilize the emulsion formed during particle preparation. These stabilizers, however, can also influence the properties of the particles formed. The type and concentration of the stabilizer selected may affect the particle size. Being present at the boundary layer between the water phase and the organic phase during particle formation, the stabilizer can also be incorporated on the particle surface, modifying particle properties such as particle zeta potential and mucoadhesion (203). Other polymers have also been evaluated as stabilizers in earlier studies such as cellulosic derivatives methylcellu-lose (MC), hydroxyethylcellulose ( ), hydroxypropylcellulose (HPC), and hydroxypropylmethylcellulose (HPMC), as well as gelatin type A and B, carbomer and poloxamer (203). 

Each 5 mL of VANTIN oral suspension contains cefpodoxime proxetil equivalent to 50 mg or 100 mg of cefpodoxime activity after constitution and the following inactive ingredients artificial flavorings, butylated hydroxy anisole, carboxymethylcellulose sodium, microcrystalline cellulose, carrageenan, citric acid, colloidal silicon dioxide, croscarmellose sodium, hydroxypropylcellulose, lactose, maltodextrin, natural flavorings, propylene glycol... 

H. Yokota, Alkalization mechanism of cellulose in hydroxypropylcellulose preparation process, J. Appl. Polym. Sci., 32 3423 (1986). 

A popular approach to improve ocular drag bioavailability is to incorporate soluble polymers into an aqueous solution to extend the drug residence time in the cul-de-sac. It is reasoned that the solution viscosity would be increased and hence solution drainage would be reduced. The more commonly used viscolyzing agents include PVA and derivatives of cellulose. Cellulosic polymers, such as methylcellulose, hydroxyethylcellulose (HEC), hydroxypropyl-methylcellulose (HPMC) and hydroxypropylcellulose (HPC), are widely used as viscolyzers showing Newtonian properties. They have common properties ... 

Hydroxyalkyl celluloses are obtained in the reaction of cellulose with alkene oxides or their corresponding chlorohydrins. The reaction is a base-catalyzed SN2-type substitution, and the reaction rate is proportional to the product [epoxide][CelI—O3]. The commercial preparations include hy-droxyethyl- and hydroxypropylcellulose for which ethylene oxide and propylene oxide are used as reagents. Hydroxyethylcellulose is formed according to the following equation ... 

Hydroxypropylcellulose is applied for similar purposes as hydroxyethyl-cellulose although its use is more limited. Because hydroxypropyl substitution improves thermoplasticity and solubility in organic solvents, hydroxypropylcellulose can also be used as a thickener for organic solutions. Hydroxy-propylation of cellulose does not result in water and alkali soluble products until the MS is close to 4. 

Hydroxyethylcellulose (HEC) and hydroxypropylcellulose (HPC) are prepared by reacting cotton linter or woodpulp with aqueous sodium hydroxide, and the resulting alkali cellulose is reacted with ethylene oxide and propylene oxide, respectively. 

Lyotropic Phases. Lyotropic cellulosic mesophases can be observed in a large variety of solvents with derivatives that can be thermotropic (ethylcellulose, hydroxypropylcellulose, acetoxypropylcellulose, etc.) or not (cellulose acetate). 

Cellulose is a fibrous, tough, water-insoluble, and crystalline substance. As a result of these characteristics, it is often converted to its derivatives in order to make it more useful. The most commonly used derivatives of cellulose are carbox-ymethylcellulose, methylcellulose, hydroxyethylceUulose, hydroxypropylcellulose, cellulose acetate, and cellulose xanthate (12). Among these derivatives, cellulose acetate and cellulose xanthate are cellulose esters, which are now widely used in the manufacturing of fibers, films, and in injection molding thermoplastics. 

Anonymous. Final report on the safety assessment of hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropyl methylcellulose and cellulose gum. J Am Coll Toxicol 1986 5(3) 1-60. 

BP Hydroxypropylcellulose JP Hydroxypropylcellulose PhEur Hydroxypropylcellulosum USPNF Hydroxypropyl cellulose... 

Wirick MG. Study of the enzymic degradation of CMC and other cellulose ethers. / Polym Sci 1968 6(Part A-1) 1965-1974. Anonymous. Final report on the safety assessment of hydroxy-ethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxypropyl methylcellulose and cellulose gum. / Am Coll Toxicol 1986 5(3) 1-60. 

JP Low-substituted hydroxypropylcellulose USPNF Low-substituted hydroxypropyl cellulose... 

Ishikawa T, Mukai B, Shiaishi S, et al. Preparation of rapidly disintegrating tablet using new types of microcrystalline cellulose (PH-M series) and low-substituted hydroxypropylcellulose or... 

Other non-ionic cellulose ethers which have been stndied in the formulation of hydrophilic matrices include high viscosity grades of hydroxypropylcellulose (HPC) and hydroxyethylcellulose (HEC) [24]. The ionic cellulose ether, sodium carboxymethylcellulose (Na CMC), with low or medium viscosity grades has... 

Acrylic acid derivates/ esters Carboxymethyl cellulose (CMC) Ethylcellulose (EC) Hydroxypropylcellulose (HPC) Hydrox5 ropylmethylcellulose (HPMC) Methylcellulose (MC)... 

Cellulose ethers can be prepared by various methods, as by using the common Williamson ether synthesis, with alkyl halides in the presence of a strong base (Fig. 32). This procedure is most often used to introduce carboxyl functions [O-carboxymethylcellulose (CMC)] or hydroxyl groups [3-hydroxypropylcellulose (HPC) and 2-hydroxyethylcellulose (HEC)]. 

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