The purpose of this study is to formulate and develop tablets dosage form containing Metronidazole which has
swelling and floating properties as a gastroretentive controlled-release drug delivery system to improve drug bioavailability.
Fifteen different formulations of effervescence-forming floating systems were designed using HPMC K15M, xanthan
gum, co-povidone, Eudragit® RL PO, pluronic® F-127 and/or polypropylene foam powder as swelling agents and sodium
bicarbonate with/ without citric acid as gas-forming agents at different compositions. Six out of these 15 formulations
which have satisfactory tablet floating behaviour were further studied with the incorporation of Metronidazole. The tablets
were evaluated based on tablet physicochemical properties, floating behaviour, swelling ability and drug dissolution studies
which were carried out using 0.1M HCl at 37°C for 8 hours. Furthermore, evaluation of the powder mixtures using
Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscope
(SEM) were investigated. Most of the tablets show good physicochemical properties except for F11 which contains
pluronic® F-127 as its release-retarding matrix-forming polymer. Other formulations show high swelling capacity, ability
to float for at least 8 hours in vitro and have sustained drug release characteristics. Data obtained indicated that F3 which
contains HPMC (12.5%w/w), xanthan gum (25%w/w), co-povidone (12.5%w/w) and sodium bicarbonate (31.7%w/w) is a
suitable formulation with short floating lag time, good floating behaviour and sustained drug release for at least 8 hours in vitro
with a zero order kinetic. Combinations of HPMC K15M and xanthan gum as swelling agents show synergistic effect in
retarding drug release and are suitable in providing the most sustained drug release system.