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Xanthan Gum
Xanthan gum is a fermentation derived natural, high molar mass anionic polyelectrolyte from Xanthomonascampestris. It consists of 1 → 4 linked β-D-glucose units
having a trisaccharide side chain attached to alternate D-glucosyl residues. The
molecular weight of this gum varies from 1.5 × 10
5
g/mol. The solution of gum
exhibits pseudoplasticbehaviour. Xanthan gum has been widely been used in targeted and controlled drug delivery in the form of nanoparticles, liposomes, niosomes, microspheres, hydrogels, dendrimers and nanofibers. The main problems
associated with unmodified form of xanthan gum are slow dissolution and substantial swelling and hence modification is required to overcome these disadvantage for
improved target release. The carboxymethylation and grafting (free radical, microwave irradiation, chemoenzyme) are the main chemical modification done to
improve physicochemical properties. Xanthan gum has shown various positive
physicochemical changes when used in combination with other hydrocolloids particularly with guar gum.
Dextrin Gum
Dextrin is a linear, water soluble, biodegradable polysaccharide of glucan composed mostly of varying glucose units linked by α (1 → 6) glucosidic bonds and
small percentage of α (1 → 3) linkages of bacterial origin. The nature of the attached
group in modified dextrin (15–100%) or degree of substitution determines its properties in term of solubility and can form self-organized nano scale particles. The
muco adhesive emulsion of cyclo-dextrin was prepared to load antibacterial, antiviral, contraceptive and antifungal agents and was also used as drug solubility
enhancer.
Animal Origin
Being the second most abundant natural polymer after cellulose, chitosan is obtained
from chitin from shrimp, carp and lobster shells. Chitosan is linear, cationic, biocompatible, non-toxic, and biodegradable polymer consisting of randomly distributed β (1 → 4) linked d-glucosamine and N-acetyl-d-glucosamine and is obtained
by alkaline deacetylation of chitin and is an introductory polysaccharide containing
a considerable percentage of nitrogen. It is a cationic polymer studied as an excipient in mucoadhesive dosage forms and controlled delivery formulations, attributing
to its gelling and adhesive properties. Chitosan has been recommended safe by various regulatory agencies in Japan, USA, Italy, Portugal and England for use as a
dietary accessory and food additive. As a polymer, chitosan has a special status due
Dietary Gums
Xanthan Gum
Xanthan gum is a fermentation derived natural, high molar mass anionic polyelectrolyte from Xanthomonascampestris. It consists of 1 → 4 linked β-D-glucose units
having a trisaccharide side chain attached to alternate D-glucosyl residues. The
molecular weight of this gum varies from 1.5 × 10
5
g/mol. The solution of gum
exhibits pseudoplasticbehaviour. Xanthan gum has been widely been used in targeted and controlled drug delivery in the form of nanoparticles, liposomes, niosomes, microspheres, hydrogels, dendrimers and nanofibers. The main problems
associated with unmodified form of xanthan gum are slow dissolution and substantial swelling and hence modification is required to overcome these disadvantage for
improved target release. The carboxymethylation and grafting (free radical, microwave irradiation, chemoenzyme) are the main chemical modification done to
improve physicochemical properties. Xanthan gum has shown various positive
physicochemical changes when used in combination with other hydrocolloids particularly with guar gum.
Dextrin Gum
Dextrin is a linear, water soluble, biodegradable polysaccharide of glucan composed mostly of varying glucose units linked by α (1 → 6) glucosidic bonds and
small percentage of α (1 → 3) linkages of bacterial origin. The nature of the attached
group in modified dextrin (15–100%) or degree of substitution determines its properties in term of solubility and can form self-organized nano scale particles. The
muco adhesive emulsion of cyclo-dextrin was prepared to load antibacterial, antiviral, contraceptive and antifungal agents and was also used as drug solubility
enhancer.
Animal Origin
Being the second most abundant natural polymer after cellulose, chitosan is obtained
from chitin from shrimp, carp and lobster shells. Chitosan is linear, cationic, biocompatible, non-toxic, and biodegradable polymer consisting of randomly distributed β (1 → 4) linked d-glucosamine and N-acetyl-d-glucosamine and is obtained
by alkaline deacetylation of chitin and is an introductory polysaccharide containing
a considerable percentage of nitrogen. It is a cationic polymer studied as an excipient in mucoadhesive dosage forms and controlled delivery formulations, attributing
to its gelling and adhesive properties. Chitosan has been recommended safe by various regulatory agencies in Japan, USA, Italy, Portugal and England for use as a
dietary accessory and food additive. As a polymer, chitosan has a special status due
Dietary Gums