Pharmacokinetic evaluation of ibuprofen controlled release matrix tablets using hydrophilic Eudragit® polymer and co-excipients

ABSTRACT

The present study was conducted to formulate controlled release dosage forms containing Ibuprofen with Eudragit® S 100 polymer. The tablets were formulated at three different ratios with the polymer to investigate the effect of different concentrations of polymer on in vitro drug release patterns/kinetics and in vivo absorption/pharmacokinetics. Pre-formulation studies were conducted including bulk density, tapped density, compressibility index, Hausner ratio and angle of repose. In vitro studies were conducted using phosphate buffer [pH 7.4] as dissolution medium. In vivo performance was evaluated using albino rabbits. Physico-chemical characteristics [i.e. dimensional tests, weight variation, hardness, friability and drug content determination] fell in the USP acceptable limits. The compressibility index was found to range between 12.02 +/- 0.01% and 18.66 +/- 0.03%, the Hausner ratio varied between 1.02 +/- 0.01 and 1.19 +/- 0.10 and the angle of repose ranged from 15.19 +/- 0.01 to 24.52 +/- 0.10, all indicating better flow properties than the bulk-reference standard. Both bulk and tapped densities also fell in the USP acceptable range. Ibuprofen market tablets showed T[max] of 2.1 +/- 0.4h, which was significantly [P-value <0.05] lower compared to that of the reference standard [i.e. 4.09 +/- 1.3h]. Ibuprofen test formulation has a half-life [T[1/2]] of 16.9 +/- 2.5h, which was significantly [P-value<0.001] higher compared to that of the reference standard [i.e. 9.23 +/- 2.9h]. Eudragit® S 100 polymers can be used efficiently to develop directly compressed prolonged release tablets