Carboxymethylcellulose preparation

Carboxymethylcellulose Sodium. Carboxymethyl ether of cellulose sodium salt (Citmcel) (8) is a white granular substance soluble in water depending on the degree of substitution. It is equally soluble in cold and hot water and may be prepared by treating alkaU cellulose with sodium chloroacetate. 

Carboxymethylcelluloses (CMC). CarboxymethylceUulose [9004 2-6] (CMC) is the carboxymethyl ether of cellulose. To prepare CMC, cellulose is steeped in sodium hydroxide solution, and the so-called alkaU cellulose is treated under controlled conditions with sodium monochloroacetate to form the sodium salt of CarboxymethylceUulose and sodium chloride. Therefore, the CMC of commerce is actuaUy sodium CarboxymethylceUulose... 

Partially hydrolyzed polyacrylamides, carboxymethylcellulose, polysaccharides, and acrylamido methylpropane sulfonate have been screened to investigate the performance of aluminum citrate as a chelate-type crosslinker. An overview of the performance of 18 different polymers has been presented in the literature [1646]. The performance of the colloidal dispersion gels depends strongly on the type and the quality of the polymer used. The gels were mixed with the polymers at two polymer concentrations, at three polymer-to-aluminum ratios, and in different concentrations of potassium chloride. The gels were quantitatively tested 1,7, 14, and 28 days after preparation. 

Prepare 500 mL of a 2% solution of carboxymethylcellulose, sodium salt, in water in the manner described in the U.S. Pharmacopeia reference above. Since the solution preparation is time-consuming, your instructor may prepare it ahead of time. Using a rotational viscometer with an appropriate spindle and a constant temperature bath, measure the viscosity of this solution at various temperatures. Plot viscosity vs. temperature. 

Prepare a carboxymethylcellulose solution as in Part A. Prepare dilutions to bracket the suspected concentration in the unknown. Measure the viscosities of the solutions and the sample with a rotational viscometer and in a constant temperature bath set at 25°C. Plot viscosity vs. concentration and determine the concentration in the unknown. 

Ion exchangers can also be made from cellulose, especially for scientific applications. They are prepared from alkali cellulose by reaction, for example, with chloroacetic acid (for preparation of sodium carboxymethylcellulose, see Example 5-6). By conversion with 2-chloroethyldiethylamine one obtains so-called DEAE-cellulose, an anion exchanger carrying 2-diethylaminoethyl groups, -C2H4N(C2H5)2. 

Avicel RC and CL are water-dispersible, colloidal, microcrystalline cellulose products made for use in liquid preparations. Avicel RC and CL are coprocessed mixtures of microcrystalline cellulose and sodium carboxymethylcellulose. The amount of NaCMC can be determined using the IC method. About 10 g of Nasonex and about 25 mg of NaCMC NF are separately refluxed with 30 mL of glacial acetic acid for 2 h. The refluxed mixture is transferred to a 100-mL volumetric flask and diluted to volume with purified water, and mixed. The ion chromatograph (IC) was equipped with a suppressed conductivity detector, a 4-mm CSRS suppressor, current at 50 mA, a 250 mm x 4-mm Ion CS 12A column and a 50 mm x 4 mm Ion CG 12A guard column. The mobile phase is 0.13% methanesulfonic acid in water with a flow rate of 1 mL/min. Equal... 

While for the complexation with poly(sodium styrene sulfonate) or sodium cellulosesulfate 1 1 stoichiometry has been reported [150] a non-stoichiometric complex results with sodium carboxymethylcellulose [150]. Optimized conditions make it possible to create membranes with various properties using the PDADMAC/sodium cellulosesulfate system [166-168]. However, the symplex formation with PDADMAC or copolymers mostly results in flocculated precipitates [27,150,169]. Highly ordered mulilayer assemblies were prepared by alternate reaction of PDADMAC and various polyanions [170,171]. Recently, the efficiency and selectictivity of protein separation via PEL coacervation were examined using PDADMAC [172]. 

A homolog of carboxymethylcellulose, the carboxyethyl derivative, can be prepared by the condensation of such acrylic derivatives as acrylamide with alkali-cellulose.30 The homolog is water-soluble, and gives a clear, viscous solution. Proposed uses are similar to those mentioned for the carboxymethyl ether. 

Aluminum salts have been prepared for use as adhesives31 or in sizing,32 by adding aluminum sulfate or alum to a solution of sodium carboxymethylcellulose while controlling the pH. Other metallic salts have received attention in relation to analytical procedures, and are discussed in this connection in Section IV. 

Various salts other than the sodium salt have also received attention in this field. For example, lacquer films are prepared by the co-precipita-tion of a resin acid with aluminum carboxymethylcellulose,84 and the barium salt86 is said to possess thixotropic properties useful in paints. One unusual application involves the preparation of the water-soluble ferrous salt86 of carboxymethylcellulose which, when applied (for example to wall-... 

Various salts reportedly form adhesives suitable for paper-hanging,102103 and these may also be employed in the manufacture of sandpaper.104 Alkaline salts of inorganic, polybasic acids apparently enhance the adhesive qualities106 of sodium carboxymethylcellulose. A large number of different, adhesive preparations containing carboxymethylcellulose were manufactured by the Germans during World War II.106... 

Sodium carboxymethylcellulose (CMC) is the most widely used water-soluble derivative of cellulose. It is prepared from alkali cellulose with sodium chloroacetate as reagent ... 

Day 4 Folin-Ciocalteau Assay on Fractions and Preparation of Carboxymethylcellulose Column... 

Carboxymethylcellulose Calcium (Calcium CMC) A calcium salt of polycar-boxymethyl ether of cellulose, calcium CMC is obtained by carboxymethylation of cellulose and conversion into calcium salt. Different molecular grades are prepared by changing the degree of carboxymethylation. It is available as a line powder, white to yellowish white in color, and hygroscopic in nature. Calcium CMC has swelling and viscosity-enhancing properties in water. It can swell twice its volume in water [25]. 

Substituted Cellulose Ethers. Since their introduction for ophthalmic use, MC and other substituted cellulose ethers such as hydroxyethylcellulose, hydroxypropylcel-lulose, hydroxypropyl methylcellulose (HPMC), and carboxymethylcellulose (CMC) have been used in artificial tear formulations.These colloids dissolve in water to produce colorless solutions of varying viscosity. They have the proper optical clarity, a refractive index similar to the cornea, and are nearly inert chemically. Their relative lack of toxicity, their viscous properties, and their beneficial effects on tear film stability have made cellulose ethers useful components of artificial tear preparations. Historically, the most frequently used representative of this group was MC. 

This ester-type anesthetic is poorly absorbed. Because it contains benzocaine, which has a low water solubility, it is prepared in a base containing petrolatum and sodium carboxymethylcellulose. Eugenol is included for its antiseptic and anodyne properties. Hydroxy-quinoline sulfate is a preservative. This ointment can be directly applied to abraded or ulcerated lesions with minimal systemic effects. It is sometimes used to temporarily relieve denture sores and painful lesions. 

Spherical pellets containing 5% triamcinolone acet-onide were prepared by Villar-Lopez and coworkers byextrusion/spheronization after formulation with microcrystalline cellulose and/or a hydrophilic excipient such as lactose, sodium carboxymethylcellulose, or p-cyclodextrin. Their suitability for coating, with a view toward colonic drug delivery, was assessed in terms of their size, sphericity, and dissolution test... 

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