Improved gastric residence time of famotidine by raft-forming drug delivery system using DOE

This study investigated the raft-forming suspension of famotidine as an anti-reflux formulation to improve the oral bioavailability of narrow absorption window drugs by enhancing gastric residence time (GRT) and preventing gastro-esophageal reflux disease (GERD).

Various combinations of raft-forming agents, such as Tragacanth gum (TG), guar gum (GG), and xanthan gum (XG), were evaluated alongside sodium alginate (SA) to develop an effective raft. Preformulation studies and preliminary screening were conducted to identify the most suitable raft-forming agent, and GG was chosen due to its mucilaginous properties. The formulation was optimized using a 32 full factorial design, with the quantities of GG and SA as independent factors and apparent viscosity and in-vitro drug release (%) as dependent factors. The in vivo floating behavior study was performed for optimized and stabilized formulation.

Among the tested batches, F6 was selected as the optimized formulation. It exhibited desirable characteristics such as adequate raft weight for extended floating in gastric fluid, improved apparent viscosity, and a significant percentage of drug release at 12 h. A mathematical model was applied to the in-vitro data to gain insights into the drug release mechanism of the formulation. The stability of the suspension was assessed under accelerated conditions, and it demonstrated satisfactory stability. The formulation remains floating in the Rabbit stomach for more than 12 h.

It concludes that the developed formulation has enhanced bioavailability in the combination of GG and SA. The floating layer of the raft prevents acid reflux, and the famotidine is retained for an extended period of time in the gastric region, preventing excess acid secretion. The developed formulations are effective for stomach ulcers and GERD, with the effect of reducing acid secretion by H2 receptor antagonists.