Preparation and evaluation of floating drug delivery system (fdds) containing an antiviral drug

Acyclovir, an antiviral drug has low oral bioavailability of about 15-30%. It shows more absorption in the upper gastro intestinal tract. The main objective is to evaluate the potential of floating alginate beads as a drug carrier for acyclovir to prolong gastric residence time of drug in its absorption window. Floating beads were prepared from sodium alginate solution containing CaCO3 as gas-forming agent using Ionotropic gelation method. To overcome the limitation of drug leaching during preparation and to have improved sustained release characteristics, alginate beads were prepared with the addition of polymers like Hydroxy propyl methyl cellulose (HPMC K4M), Eudragit RL 100 and Xanthan gum. Beads were also prepared by using Pectin (polyelectrolyte) containing cross linking solution. The compatibility of drug with the polymer was confirmed through the FT-IR studies. The prepared beads were evaluated for percentage drug loading, entrapment efficiency, surface morphology and in vitro release characteristics to know the effect of addition of these polymers to alginate solution and the addition of Pectin to cross linking solution. Pectin treated beads prepared with Xanthan gum & Pectin not only showed improved percentage drug loading but also exhibited sustained drug release in the pH 1.2. So these floating alginate beads may act as a promising carrier for acyclovir to improve its oral bioavailability.