Formulation, optimization, and evaluation of raft-forming formulations containing Nizatidine

The main objective of this research is to formulate, optimize, and evaluate raft-forming chewable tablets of Nizatidine. Various raft-forming agents were used in preliminary screening. Sodium alginate showed maximum raft strength, so tablets were prepared using sodium alginate as the raft forming agent, along with calcium carbonate (CaCO₃) as antacid and raft strengthening agent, and sodium bicarbonate (NaHCO₃) as a gas generating agent.

Raft forming chewable tablets containing Nizatidine were prepared by direct compression and wet granulation methods, and evaluated for drug content, acid neutralization capacity, raft strength, and in-vitro drug release in 0.1 N HCl. Box-Behnken design was used for optimization.

Two optimized formulations were predicted from the design space. The first optimized recommended concentrations of the independent variables were predicted to be X₁ = 275.92 mg, X₂ = 28.60 mg, and X₃ = 202.14 mg for direct compression technique and the second optimized recommended concentrations were predicted to be X₁ = 253.62 mg, X₂ = 24.60 mg, and X₃ = 201.77 mg for wet granulation technique. Optimized formulations were stable at accelerated environmental testing for six months at 35 °C and 45 °C with 75% relative humidity. X-Ray showed that the raft floated immediately after ingestion and remained intact for ∼3 h.

Raft was successfully formed and optimized. Upon chewing tablets, a raft is formed on stomach content. That results in rapid relief of acid burning symptoms and delivering the drug into systemic circulation with enhanced bioavailability.