Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Microcrystalline chitosan

Oechslein, Fricker, and Kissel " studied various powder formulations of mucoadhesive polymers for their efficacy to increase the nasal absorption of octreotide in rats. Although chitosan showed the highest water uptake (chitosan > microcrystalline cellulose > semicrystalline cellulose > pectin = hydroxyethyl starch = alginic acid = Sephadex G25), the highest peptide drug bioavailability was found after coadministration of alginic acid and Sephadex G25 powders (4.1 and 5.56%, respectively). The authors concluded that the calcium-binding properties of the polymers used correlated better with the increased octreotide bioavailability. [Pg.1175]

We express our gratitude to BRACE GmbH for the donation of some analyzed biopolymers (alginate, chitosan, microcrystalline cellulose, hydroxypropyl methylcellulose, dextrin, and pullulan) used in this entry. [Pg.635]

Sakkinen, M., et al. 2004. Gamma scintigraphic evaluation of the fate of microcrystalline chitosan granules in human stomach. Eur J Pharm Biopharm 57 133. [Pg.82]

A slightly different approach is to deliver the active drug in a dry powder carrier system, for example microcrystalline cellulose, hydroxyethyl starch, cross-linked dextran, microcrystalline chitosan, carbomer, pectin, or alginic acid. The polymer absorbs water upon contact with the nasal mucosa and swells to become a viscous gel, often demonstrating bioadhesive properties. Such systems can remain in the nasal cavity for as long as six hours. For example, the bioavailability in rats of the somatostatin analogue, octreotide, was shown to be enhanced by the co-administration of alginic acid and cross-linked dextran as dry powders. [Pg.241]

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... [Pg.655]

Powder Dry blending Octreotide Dextran, microcrystalline cellulose, semicrystalline cellulose, hydoxyethyl starch, microcrystalline chitosan, pectin, alginic acid In rats Correlation between carrier calcium binding properties and their potential as nasal absorption enhancers for peptides 40... [Pg.673]

Polymeric thickeners Gums Acacia Alginates Carageenan Chitosan Collagen Tragacanth Xantham Celluloses Sodium carboxymethyl Hydroxyethyl Hydroxypropyl Hyd roxypro pyl m ethyl Acrylic acids Carbomers Polycarbophil Colloidal solids Silica Clays Microcrystalline cellulose Hydrogels Polyvinyl alcohol Polyvinylpyrrolidone Thermoreversible polymers Poloxamers... [Pg.545]

Ethylene-vinyl acetate copolymer Glyceryl palmitostearate Hydrogenated castor and soybean oil Microcrystalline wax Corn starch Maltodextrin Pregelatinized starch Isomalt Potato starch Citric add Sodium bicarbonate Methacrylic acid copolymer type C Chitosan Xanthan gum Agar Povidone Lactose... [Pg.219]

Many different complexing agents and adsorbents were examined. As ligands attaching ions of Cr, Co, and Cs, PEI, microcrystalline chitosan (MCH), polyacrylic acid (PAA)... [Pg.676]

Ratajska, M., Wisniewska-Wrona, M., Strohin, G. et al. 2003b. Studies on biodegradation of microcrystalline chitosan in aqneons medium. Fibers Text. East. Eur. 11 59-63. [Pg.115]

A composition of a selected chitosan form and its derivative, such as microcrystalline chitosan or a gel from chitosan salt with poly-Af-vinylopyrolidone, was used to manufacture new dressings for veterinary use to protect injured animal skin successfully (Wisniewska-Wrona et al. 2002). Strong bacteriostatic/bactericidal activity and improved mechanical properties were reported for these dressings. [Pg.473]

M. Sakkinen, J. Marvola, H. Kanerva, K. Lindevall, M. Llipponen, T. Kekki, A. Ahonen, and M. Marvola, Gamma scintigraphic evaluation of the fate of microcrystalline chitosan granules in human stomach, Eur. J. Pharm. Biopharm., 57,133-143,2004. [Pg.58]

Owing to the hydrophilic nature of chitosan, this compound has been used directly as compressible diluent in tablets. Chitosan has excellent properties as excipient for direct compression of tablets, where the addition of 50% chitosan results in rapid disintegration. The DD determines the extent of moisture absorption. Also, in immediate-release formulations, e.g., as a disintegrant in small amounts, where it has been found to have effects similar to or better than those of microcrystalline cellulose. Chitosan at concentrations higher than 5% is a better disintegrate than corn starch and microcrystalline cellulose, depending on chitosan crystallinity, DD, MW and particle size [61]. In addition, it has excellent tablet binder properties compared to other excipients [62]. [Pg.282]

Microcrystalline chitosan gel/sodium alginate (2 1)-sodium cellulose xanthate... [Pg.385]

Table 13 Rf Values of Water-Soluble Food Dyes on Layers of (a) DEAE-Cellulose, (b) PAB-Cellulose, (c) CHITOSAN, and (d) Microcrystalline Cellulose... Table 13 Rf Values of Water-Soluble Food Dyes on Layers of (a) DEAE-Cellulose, (b) PAB-Cellulose, (c) CHITOSAN, and (d) Microcrystalline Cellulose...
Table 6. Results of determining enthalpy of ehitin (CT), chitosan (CTS) and microcrystalline cellulose (MCC) with water at 298.15 K [47-49,117,122]... Table 6. Results of determining enthalpy of ehitin (CT), chitosan (CTS) and microcrystalline cellulose (MCC) with water at 298.15 K [47-49,117,122]...
Sakkinen M, Linna A, Ojala S, Jiirjenson H, Veski P, Marvola M. In vivo evaluation of matrix granules containing microcrystalline chitosan as a gel-forming excipient. Int J Pharm. 250 (1) 121-Til, 2003. [Pg.514]


See other pages where Microcrystalline chitosan is mentioned: [Pg.493]    [Pg.493]    [Pg.653]    [Pg.656]    [Pg.876]    [Pg.267]    [Pg.474]    [Pg.626]    [Pg.635]    [Pg.699]    [Pg.211]    [Pg.109]    [Pg.105]    [Pg.48]    [Pg.175]    [Pg.361]    [Pg.482]    [Pg.480]    [Pg.483]    [Pg.83]   
See also in sourсe #XX -- [ Pg.265 ]




SEARCH



Microcrystalline

© 2024 chempedia.info