Xanthan Gum and Alginate Based Controlled Release Theophylline Formulations

Abstract

The oral absorption of theophyll ine from two sustained release formulations, formulated using xanthan gum or sodium alginate, has been investigated in the beagle dog. A commercial product was used for comparison. Dissolution tests and an i n v i v o dog study both indicated that the xanthan gum tablet released drug at a constant rate and performed as a pH independent zero-order controlled release formulation. With the alginate tablet, faster dissolution rates were observed when acid medium was present. pH dependent release behavior o f the alginate formulation is explained. gel behaviors in these two polymers are discussed. The relative oral bioavailabilities of these two formulations in dog were 74-The Drug release mechanisms which are influenced by the 84% compared to immediately releasing capsules, and three-fold that of the commercial product with an equivalent dose.

Use of hydrophilic natural gums in formulation of sustained-release matrix tablets of tramadol hydrochloride

“…25 Our previous studies 26 with X gum, a natural derivative of cellulose, showed that the drug release from this microbial exocellular polysaccharide follows zero-order or almost time-independent release kinetics, which is in accordance with the finding of others. [27][28][29] In high concentrations of X (X 8 H 2 and X 6 H 4 ), considering the high level of erodability of X (Figure 2), a Hixson-Crowell release kinetic is concluded ( Table 3). As there is no significant difference between r 2 of the zeroorder and Hixson-Crowell kinetic in X 8 H 2 (Table 3), it may be concluded that drug is released both by erosion and by diffusion within the matrix and often approximates zeroorder for a significant part of total release time.…”

Synthesis, physicochemical, structural and rheological characterizations of carboxymethyl xanthan derivatives

“…As a pharmaceutical excipient, it is used as a suspending agent for sustained-release suspensions (Junyaprasert and Manwiwattanakul, 2008) and in sustained-release matrix tablets (Talukdar et al, 1998;Lu et al, 1991;Dhopeshwarkar and Zatz, 1993;Billa et al, 2000). In ophthalmic liquid dosage form, xanthan gum delays the release of active substances, increasing the therapeutic activity of pharmaceutical formulations (Hoepfner et al, 2002), and prolongs the retention time of dosages applied to the precorneal area (Ceulemans et al, 2002).…”

Fabrication of Triple-Layer Matrix Tablets of Venlafaxine Hydrochloride Using Xanthan Gum

“…Its compatibility with a wide variety of ingredients makes it particularly effective in these applications. Xanthan gum has been evaluated as a hydrophilic matrix for different model drugs including theophylline (12), cephalexin (13), prednisolone (14), indomethacin (15), and diclofenac sodium (16).…”