Optimization and evaluation of gastroretentive ranitidine HCl microspheres by using design expert software

Area of Science:

• Pharmaceutical Sciences
• Materials Science

Background:

• Chitosan is a cationic, biocompatible polymer ideal for drug delivery systems, particularly in acidic environments.
• Gastroretentive drug delivery aims to prolong drug residence time in the stomach for improved absorption.
• Ranitidine HCl is a commonly prescribed drug for acid-related gastrointestinal disorders.

Purpose of the Study:

• To develop and optimize multiunit chitosan-based floating microspheres for gastroretentive delivery of Ranitidine HCl.
• To evaluate the effect of process variables on drug entrapment, particle size, and bioadhesion.
• To assess the stability of the optimized formulation.

Main Methods:

• Ionotropic gelation method was employed for microsphere preparation.
• Central composite design and response surface methodology were used for optimization.
• Ex vivo bioadhesion and floating lag time were evaluated in simulated gastric fluid (pH 1.2).

Main Results:

• Optimized microspheres achieved 74.73% drug entrapment efficiency and 71.68% bioadhesion after 8 hours.
• Particle size ranged from 608.24 to 720.80 μm, with optimized size at 707.26 μm.
• Floating lag time was 40s, indicating rapid buoyancy. Accelerated stability studies showed no significant change in drug content.

Conclusions:

• The developed chitosan-based floating microspheres are suitable for gastroretentive delivery of Ranitidine HCl.
• The optimization strategy effectively predicted and achieved desired physicochemical properties.
• The formulation exhibits good stability, supporting its potential for clinical application.