Gum guar

The use of guar gum as carrier in the formulation of sustained release systems has been assessed. Tablets with diltiazem as model drug were prepared. Guar gum is an economical alternative (25). 

Guar gum based three-layer matrix tablets for oral controlled delivery of highly soluble metoprolol tartrate as a model drug have been evaluated (26). 

BP Guar galactomannan PhEur Guar galactomannanum USPNF Guar gum 

E412 Galactosol guar flour jaguar gum Meyprogat Mey-prodor Meyprofin. 

Guar gum consists of linear chains of (1— 4)-P-D-mannopyr-anosyl units with a-D-galactopyranosyl units attached by (1 6) linkages. The ratio of D-galactose to D-mannose is between 1 1.4 and 1 2. See also Section 8. 

Suspending agent tablet binder tablet disintegrant viscosity-increasing agent. 

Guar gum is a galactomannan, commonly used in cosmetics, food products, and pharmaceutical formulations. It has also been investigated in the preparation of sustained-release matrix tablets in the place of cellulose derivatives such as methylcellu-lose.  

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Guar gum [9000-30-0] derived from the seed of a legume (11,16), is used as a flocculant in the filtration of mineral pulps leached with acid or cyanide for the recovery of uranium and gold (16). It is also used as a retention aid, usually in a chemically modified form (14,17). Starch and guar gum are subject to biological degradation in solution, so they are usually sold as dry powders that are dissolved immediately before use. Starch requires heating in most cases to be fully dissolved. 

StmcturaHy, guar gum comprises a straight chain of D-mannose with a D-galactose side chain on approximately every other mannose unit the ratio of mannose to galactose is 2 1 (53). Guar gum has a molecular weight on the order of 220,000 (54). 

In the food industry, guar gum is appHed as a stabilizer in ice cream and frozen desserts (58), and it is also used as a stabilizer for salad dressings, sauces, frozen foods, and pet foods. 

In the food industry, locust bean gum is used as a stabilizer in ice cream and in the preparation of processed cheese and extmded meat products. It is also used as an emulsifier and stabilizer of dressings and sauces and overall has similar properties to those outiined for guar gum. 

Guar gum is a nonionic, branched-chain polysaccharide, a galactomaiman that is usually hydroxypropylated for use in drilling (52). It produces viscous solutions in fresh or salt water at concentrations of ca 3—6 kg/m (1—2 lb /bbl). It is used in soHds-free and low soflds muds and degrades rapidly above 80°C, limiting its use to shallow wells. 

For products intended to remain stable dispersions for an extended period, a particle size of 2 p.m or less is desirable. A thickening agent is usuaUy added after the reaction has been completed and the mixture is cooled in order to prevent settling and agglomeration. Examples of thickeners are guar gum, xanthan gum, and hydroxyethylceUulose. The final products are generaUy between 40 and 50% soUds, with a viscosity of 1500 5000 mPa-s(=cP). 

Cross-Linking of Polyols. Polyols such as natural polysaccharides, eg, cellulose, starch, guar gum and their derivatives, and polyvinyl alcohol and its derivatives can be cross-linked by organic titanates. 

Polymer chains of guar gum and its derivatives, in fact of all galactomannans, are readily cross-linked with borate and titanium ions. Gels formed in this way are mbbery in nature. 

Commercial locust bean gum is the ground endosperm of the seeds of the locust bean (carob) tree. The general properties of locust bean gum are similar to those of guar gum. Differences are its low cold-water solubiUty and its synergistic gelation with kappa-carrageenan, furceUaran, and xanthan... 

Microcrystalline ceUuloses ate marketed under the trade name Avicel. The physical characteristics of microcrystalline ceUuloses differ markedly from those of the original ceUulose. The ftee-flowiag powders have particle sizes as smaU as 0.2—10 p.m. Avicel ceUuloses coated with xanthan gum, guar gum, or carboxy-methylceUulose to modify and stabilize their properties are also available. The Avicel products are promoted for use ia low calorie whipped toppiags andiciags andia fat-reduced salad dressiags and frozen desserts (see Fat substitutes). 

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