Poly carboxymethyl cellulose

K. El-Salmawi, M. Zaid, S. Ibraheim, A. El-Naggar, A. Zahran, Sorption of dye wastes by poly (vinyl alc(4iol)/poly (carboxymethyl cellulose) blend grafted through a radiation method, J. Appl. Polym. Sci. 82 (1) (2001) 136-142. 

Lead azide is not readily dead-pressed, ie, pressed to a point where it can no longer be initiated. However, this condition is somewhat dependent on the output of the mixture used to ignite the lead azide and the degree of confinement of the system. Because lead azide is a nonconductor, it may be mixed with flaked graphite to form a conductive mix for use in low energy electric detonators. A number of different types of lead azide have been prepared to improve its handling characteristics and performance and to decrease sensitivity. In addition to the dextrinated lead azide commonly used in the United States, service lead azide, which contains a minimum of 97% lead azide and no protective colloid, is used in the United Kingdom. Other varieties include colloidal lead azide (3—4 pm), poly(vinyl alcohol)-coated lead azide, and British RE) 1333 and RE) 1343 lead azide which is precipitated in the presence of carboxymethyl cellulose (88—92). 

The main polymers used as thickeners are modified celluloses and poly(acrylic acid). Several different modified celluloses are available, including methyl-, hydroxypropyl methyl-, and sodium carboxymethyl-cellulose and their properties vary according to the number and distribution of the substituents and according to relative molar mass of the parent cellulose. Hence a range of materials is available, some of which dissolve more readily than others, and which provide a wide spread of possible solution viscosities. Poly(acrylic acid) is also used as a thickener, and is also available in a range of relative molar masses which give rise to give solutions of different viscosities. 

Synthetic examples include the poly(meth)acrylates used as flocculating agents for water purification. Biological examples are the proteins, nucleic acids, and pectins. Chemically modified biopolymers of this class are carboxymethyl cellulose and the lignin sulfonates. Polyelectrolytes with cationic and anionic substituents in the same macromolecule are called polyampholytes. 

Sodium carboxymethyl cellulose Poly(vinyl pryidine)... 

Cellulose disintegrants have been studied as insoluble matrices for sustained release tablets. Anionically charged carboxymethyl cellulose (sodium salt) was found to be inferior to methyl cellulose and poly(vinyl pyrollidone) as a binding agent for oxyphenbutazone tablets [291], However sodium carboxymethyl cellulose has found application as a dispersing agent for ibuprofen microspheres... 

The bioadhesive characteristics of tablets for oral use made from modified starch, poly(acrylic acid), polyethylene glycol) and sodium carboxymethyl cellulose were recently investigated [406]. In this work, the force and energy adhesion were determined in vitro, and maximum adhesion times were evaluated in vivo in humans [406], In the in vitro, studies, the poly(acrylic add) gave the best performance, however in vivo bioadhesion was not strongly correletated with... 

The hemocompatibility of poly(amido-amine) polyelectrolyte complexes was recently studied by Xi, Zhang and coworkers [499, 500]. The poly(amido-amine) was based on piperazine and methylene bisacrylamide, and the polyelectrolyte complexes were obtained from the reaction of poly(amido-amine) with alginic acid, carboxymethyl cellulose or poly(methacrylic acid). Complexes of polyamido-amine and alginic acid with a 1 2 ratio gave the best hemocompatibility. Finally, the blood compatibility of polyelectrolyte complexes based on anionic and cationic cellulose derivatives were studied by Ito et al. [338], In vivo, good blood compatibility of complexes formed from quaternary hy-droxyethyl cellulose reacted with carboxymethyl cellulose and cellulose sulfate was observed. 

Macromolecular chemistry covers a particularly wide field which includes natural polymeric material, such as proteins, cellulose, gums and natural rubber industrial derivatives of natural polymers, such as sodium carboxymethyl cellulose, rayon and vulcanised rubber and the purely synthetic polymers, such as polythene (polyethylene), Teflon (polytetrafluoroethylene), polystyrene, Perspex (poly (methyl... 

Kennedy, J. F., Melo, E. H. M., Crescenzi, V., Dentini, M., and Matricardi, P. (1992). A rapid quantitative determination of pectin and carboxymethyl cellulose in solution using poly(hexamethylenebiguanidinium) chloride. Carbohydr. Polym. 17 199-203. 

Research on nasal powder drug delivery has employed polymers such as starch, dextrans, polyacrylic acid derivatives (e.g., carbopol, polycarbophil), cellulose derivatives (microcrystalline cellulose, semicrystalline cellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), chitosan, sodium alginate, hyaluronans, and polyanhydrides such as poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA). Many of these polymers have already been used as excipients in pharmaceutical formulations and are often referred to as first-generation bioadhesives [38-45], In nasal dry powder a single bioadhesive polymer or a... 

A review of vaginal bioadhesive formulations indicates that bioadhesive tablets have been used for localized treatment of diseases in the vaginal tissue.F ° l For example. Bleomycin, an antitumor agent, was incorporated into a flat-faced disk fabricated from a combination of hydroxypropyl cellulose and poly-(acrylic acid) (Carbopol 934). ° The tablet was designed to release Bleomycin at a slow rate to minimize irritation to healthy mucosa. Another vaginal tablet is formulated from the combination of poly(acrylic acid) with hydroxypropyl methylcellulose and ethylcellu-lose. Other polymer combinations evaluated for potential bioadhesive vaginal delivery include poly(acrylic acid) and sodium carboxymethyl cellulose with Avicel PH102 (methylcellulose) as the diluent. Insulin has been formulated in a cross-linked poly(acrylic acid) gel... 

Base polymer Starch—graft copolymerization, carboxymethylation Cellulose—graft copolymerization, carboxymethylation Synthetic polymers—poly(acrylate), poly(vinyl alcohol), poly(acrylamide), poly(oxyethylene), cationic polymer... 

Textile industry recovery of polymer agents (starch, carboxymethyl cellulose and poly(vinyl alcohol)). 

L Jamstrdm, L Lason, M Rigdahl, U Erikson. Flocculation in kaolin suspensions induced by modified starches 2. Oxidized and hydrophobically modified oxidized starch in comparison with poly(vinyl alcohol) and carboxymethyl-cellulose. Coll Surf A 104 207-216, 1995. 

The extent of this shift is indicated in the figure for the two shear rate extremes of 50 sec" and 300 sec", respectively. This shift is comparatively small and does not invalidate the general character of the relationship referred to in Figure 9. Apart from PEO, the data of this figure relate to aqueous solutions of hydroxyethyl cellulose (HEC), sodium carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), and poly-(vinyl alcohol) (PVA). The behavior of the solutions at shear rates lower than 50 sec" was not measured because of the low intensity of the shear-induced current noise. 

HPMC hydroxypropylmethylcellulose CMC carboxymethyl-cellulose HEC hydroxyethylcellulose HPC hydroxypropyl-cellulose EC ethylcellulose PVP polyvinylpyrrolidone PVA poly(vinyl alcohol) poly(HEMA) poly(hydroxyethyl methacrylate). 

Ekici S (2011) Intelligent poly(A-isopropylacrylamide)-carboxymethyl cellulose full interpenetrating polymeric networks for protein adsorption studies. J Mater Sd 46 2843-2850... 

Vasile, C., Bumbu, G.G., Dumitriu, R.P., Staikos, G., (2004), Comparative study of the behavior of carboxymethyl cellulose-g-poly(N-isopropylaciylamide) copolymers and their equivalent physical blends. European polymer Journal, Vol. 40, No. 6, (June 2004) pp 1209-1215, ISSN 0014-3057. 

Many PECs are prepared using chitosan as the polycationic component, therefore they will be discussed separately. Chitosan, the product of N-deacetylation of chitin, is one of the most commonly used cationic polymers of pharmaceutical interest due to its biocompatibility, nontoxicity, and mucoadhesivity. It is frequently used to form PECs, often in combination with alginate, carrageenan," hyaluronic acid, chondroitin sulfate (CS)," carboxymethyl cellulose (CMC), or poly(galacturonic acid), since these are natural anionic polysaccharides with favorable pharmaceutical properties. 

Hyaluronic acid derivatives Carboxymethyl cellulose Poly(jS-hydroxybutyrate)... 

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