Karaya Gum

Karaya Gum :: chemistry Latest Paper: Drug Dev Ind Pharm. 2004 Jul ;30 (6):609-17 15285334 (P,S,G,E,B)

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n e Evaluation of selected polysaccharide excipients in buccoadhesive tablets for sustained release of nicotine. w s S Calum R Park, Dale L Munday t a School of Pharmacy, The Robert Gordon University, Aberdeen, Scotland, UK. b l Some naturally occurring biocompatible materials were evaluated as mucoadhesive controlled release excipients for buccal drug e delivery. A range of tablets were prepared containing -50% w/w xanthan gum, karaya gum, guar gum, and glycol chitosan and were tested

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for swelling, drug release, and mucoadhesion. Guar gum was a poor mucoadhesive and lacked sufficient physical integrity for buccal n

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delivery. Karaya gum demonstrated superior adhesion to guar gum and was able to provide zero-order drug release, but concentrations i greater than 50% w/w may be required to provide suitable sustained release. Xanthan gum showed strong adhesion to the mucosal membrane and the 50% w/w formulation produced zero-order drug release over 4 hours, about the normal time interval between daily meals. Glycol chitosan produced the strongest adhesion, but concentrations greater than 50% w/w are required to produce a nonerodible matrix that can control drug release for over 4 hours. Swelling properties of the tablets were found to be a valuable indicator of the ability of the material to produce sustained release. Swelling studies also gave an indication of the adhesion values of the gum material where adhesion was solely dependent upon penetration of the polymer chains into the mucus layer. Mesh-terms: Karaya Gum :: chemistry; Administration, Buccal; Chemistry, Pharmaceutical; Chitin :: analogs & derivatives; Chitin ::

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chemistry; Comparative Study; Delayed-Action Preparations :: administration & dosage; Delayed-Action Preparations :: chemistry; Drug Carriers :: chemistry; Excipients :: chemistry; Galactans :: chemistry; Kinetics; Mannans :: chemistry; Nicotine :: administration & dosage; Nicotine :: chemistry; Polysaccharides :: chemistry; Polysaccharides, Bacterial :: chemistry; Tablets; Time Factors;

Most cited papers: Glycobiology. 1996 Mar ;6 (2):131-9 8727785 (P,S,G,E,B) Cited:4 [Cited?] Characterization of carbohydrate structural features recognized by anti-arabinogalactan-protein monoclonal antibodies. E A Yates, J F Valdor, S M Haslam, H R Morris, A Dell, W Mackie, J P Knox Centre for Plant Biochemistry & Biotechnology, University of Leeds, United Kingdom. Arabinogalactan-proteins (AGPs) are a diverse class of plant cell surface proteoglycans implicated in a range of fundamental processes associated with plant cell development. Anti-AGP monoclonal antibodies have been used extensively for the investigation of the developmental regulation of AGPs although virtually nothing is known about the structure of the carbohydrate epitopes recognised by these antibodies. In this report, a series of methyl glycosides of monosaccharides and a range of oligosaccharides that are elements of the carbohydrate component of AGPs have been investigated for recognition by previously derived anti-AGP monoclonal antibodies. No clear evidence was obtained for the involvement of terminal arabinofuranosides, nor of the galactan backbone, in the recognition of the glycan structure of AGPs by any of the antibodies used in this study. Interestingly, the most effective inhibitor of the binding of the monoclonal

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antibodies MAC207, JIM4 and JIM13 to exudate gum antigens was an acidic trisaccharide, isolated from a partial acid hydrolysate of gum s

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karaya which has the structure: GlcA beta(1-->3) GalA alpha(1-->2)Rha, determined by a combination of FAB-MS, GC-MS and NMR i spectroscopy.

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