Effect of grinding on in vitro fl oating behaviour of effervescent matrix tablets of ciprofl oxacin hydrochloride: Negative impact on initial buoyancy

Abstract

The purpose of this study was to form dispersion of sodium bicarbonate in hydroxylpropyl methyl cellulose (HPMC K4M) matrix and investigate its impact on in vitro
floating behaviour and drug release. The dispersion of sodium bicarbonate in HPMC
K4M was achieved by grinding method using mortar and pestle. The in vitro floating
behaviour and drug release of matrix tablets having grinding dispersion (GD) were
compared with matrix tablets having physical mixture. The GD matrix tablets were
having higher values of buoyancy lag time (BLT) in comparison to PM matrix tablets.
However, the floating duration of GD matrix tablets was higher than that for PM matrix
tablets. The swelling extent was also found higher for GD matrix tablets. Higher drug
release rate was achieved with GD matrix tablets and drug release kinetics was explained
by korsemeyer-peppas model. The values of diffusion coefficient (n) were found between
0.45−0.89, which indicates the anomalous type of drug transport.