Formulation and evaluation of Psyllium Husk-containing granules as a carrier to sustain the release of Water-Soluble drugs II

Abstract

In previous work, the use of psyllium huskas the main component of sustained release preparations, was investigated. Granules of Metformin HCl containing different hydrocolloids namely; psyllium Husk and sodium carboxy-methyl cellulose (Na CMC), “System I”, and granules of sodium salicylate containing these hydrocolloids in addition to stearic acid, “System II’ were prepared. In vitro release studies in phosphate buffer solution (pH 6.8) clearly revealed the superiority of psyllium husk and Na CMCcombination in sustaining the release of both drugs. The introduction of stearic acid in formulations SC5 and SP5 have, significantly, slowed down the release of Sodium salicylate to 46% and 53%, respectively, after 7 hours. Mathematical modeling of the release data revealed that the release mechanism which describes the diffusion of both drugs from these systems is driven by a complex behavior such as swelling, matrix erosion as well as diffusion through the swollen matrix of most formulations. Evaluation of the drug release mechanism from these systems suggested that the release could be described by a complex mechanism, which may involve First-order kinetics, Higuchi diffusion controlled as well as Korsmeyer Peppas models