Formulation and in vitro evaluation of effervescent bilayer floating controlled release tablets of clarithromycin and famotidine

The development of floating tablets with required buoyancy, lag time, and controlling release behaviour of drugs at target site is truly interesting and challenging task for researchers. Current study is concerned with the designing of effervescent floating controlled release tablets of clarithromycin and famotidine to treat peptic ulcer due to Helicobacter pylori (H. pylori) infection. Five formulations (F1-F5) were prepared, among which three formulations were of bilayered tablets while the remaining were included as plain tablets. These tablets were prepared by direct compression method using hydroxypropyl methylcellulose (HPMC) K100M, HPMC K4M and sodium bicarbonate as swelling and floating agents respectively. The qualitative tests such as thickness, hardness, weight variation, friability and uniformity of content were performed to ensure the quality of prepared tablets. The floating lag time of all formulations ranged from 14 to 20 seconds. The effervescent floating tablets with HPMC K4M (F1, F3 & F5) attained the total floating time of more than 12 hours, while tablets prepared with HPMC K100M (F2 & F4) achieved the total floating time of less than 7 hours. This difference in floating behaviour could be due to the variation in compaction and flow properties of the two polymers. The formulations with HPMC K100M (F2 & F4) have comparatively more sustained drug release properties when compared to F1, F3 and F4 using HPMC K4M as swelling and floating polymers. This could be attributed to better compaction of HPMC K100M. The prepared tablets follow non-Fickian diffusion kinetics. Overall, these floating controlled release effervescent bilayer and plain tablets may enhance the compliance and therapeutic outcomes of clarithromycin and famotidine in treatment of H. pylori.