Physicochemical characterization and evaluation of suspending properties of arabinoxylan from Ispaghula (Plantago ovata) husk

The purpose of this study is to evaluate the use of arabinoxylan as potential suspending agent, an effective alternative to commercially used excipients for the preparation of pharmaceutical suspensions. Alkali extraction was done to separate arabinoxylan from ispaghula (Plantago ovata) seed husk by alkali extraction its physicochemical characterization was done and the suspending properties of arabinoxylan isolated were evaluated comparatively with those of bentonite at different concentration ranges of 0.125,0.25,0.5 and 1% in Zinc oxide suspension. The parameters employed for evaluation were sedimentation volume, degree of flocculation, flow rate, density, pH, redispersibility, microbiological evaluation and particle size analysis. Physicochemical characterization of arabinoxylan indicates its suitability as excipient as it has fair flow properties, low moisture content and almost neutral pH. Arabinoxylan at low conc. 0.125% showed sedimentation volume comparable to commercially used suspending agents such as bentonite 1% while suspensions containing higher concentrations such as 0.25% (sedimentation volume 92%), 0.5% (sedimentation volume 94%) and 1% conc. (sedimentation volume 98%) of arabinoxylan remained almost completely suspended during study period of 7 days. Formulations containing 0.125% and 0.25% arabinoxylan as suspending agents are easily redispersible as compared to bentonite containing formulation while formulation containing 0.5% arabinoxylan are moderately redispersible while foimulation containing 1% suspending agent gel upon storage and was not redispersible. Furthermore arabinoxylan produces stable, highly flocculated suspension, which fulfilled microbiological, and particle size specifications, however the formulations containing higher arabinoxylan 1% concentration gel upon storage. So it is concluded that arabinoxylan could be used as effective suspending agent at low concentrations in Zinc oxide suspension.