Design, characterization and in vitro evaluation of 5-aminosalicylic acid loaded N-succinyl-chitosan microparticles for colon specific delivery

Chitosan–xanthan gum microparticle-based oral tablet for colon-targeted and sustained delivery of quercetin

“…For matrix tablets, an n value of around 0.45 indicates Fickian diffusion-controlled mechanism, while an n value of around 0.89 indicates relaxation, erosion-controlled release. Intermediate values (0.455n50.89) suggest dual mechanism (anomalous transport) of both diffusion and erosion (Korsmeyer et al, 1983;Siepmann and Peppas, 2001;Mura et al, 2012).…”

“…Natural polymers, such as chitosan, pectin, galactomannan, guar gum and xanthan gum, can improve residence time in the gastrointestinal (GI) tract, thus leading to increased oral bioavailability of poorly absorbable drugs because of their ability to adhere to the mucus layer, favour localization of the dosage form at a specific site and reduce local irritation (Xu et al, 2007a(Xu et al, , 2007bPinto, 2010). However, the use of these polysaccharides may be limited by their solubility in the gastric fluids, preventing their integrity until the colonic region (Pinto, 2010;Mura et al, 2012). In a previous work, the advantages of liposomes and chitosan-xanthan gum complex polymer were combined in a multiparticulate tablet to bypass the stomach and deliver anti-inflammatory phycocyanin to the colon after oral administration.…”

Fenugreek gum derivatives with improved bioadhesion and controlled drug release: In vitro and in vivo characterization

“…Reports in the literature suggest that the derivatives of polysaccharides (amine, thiol, carboxymethyl) [2e5] can be employed to manipulate swelling, bioadhesion and drug release [4e7]. A few examples of polysaccharide derivatives already reported in literature include N-(2-hydroxy) propyl-3-trimethyl ammonium chitosan [8], glycol chitosan [9], n-succinyl chitosan [10], thiolated hydroxyl ethyl cellulose [11], carboxymethyl tamarind kernel powder [12], aminated tamarind kernel polysaccharide [5], thiolated chitosan [13].…”

Oral administration of pH-sensitive curcumin-loaded microparticles for ulcerative colitis therapy

“…With respect to colitis-targeting drug release, pH-sensitive systems represent a leading approach because the pH differs along the GIT [20]. Eudragit S100 (ERS100), which is the most commonly investigated biocompatible polymer for colon-specific drug delivery, has been accepted for oral administration by the regulatory agencies of the U.S., Europe and Japan [21].…”