Efficient Loading of Rabeprazole Sodium via Porous Anion Exchange Resin for Enteric Delivery

Rabeprazole sodium (RAB), a widely used proton pump inhibitor for treating gastroesophageal reflux disease (GERD), faces limitations in administration to pediatric and dysphagic patients due to the swallowing difficulties posed by conventional oral solid formulations. To overcome these issues, this study developed a pediatric-friendly oral RAB formulation based on a novel anion exchange resin (AER). The synthesized AER exhibited a regular spherical morphology, high porosity, and uniform particle size distribution. RAB was efficiently loaded via ion exchange to form RAB-loaded AER complexes (RAB@AER), achieving a 1.63-fold higher drug loading capacity than that of conventional resins. RAB@AER were subsequently coated with Eudragit L100 using an emulsion-solvent evaporation method, yielding microcapsules consisting of RAB-loaded AER coated by L100 (RAB@AER@L100). In vitro release studies confirmed the enteric protection of the microcapsules, with negligible drug release in acidic medium (pH 1.2) and sustained release under neutral conditions (pH 6.8). The RAB@AER@L100 enteric suspension was developed by blending the microcapsules with suitable excipients, requiring reconstitution with water before oral administration. Pharmacokinetic evaluation in rats revealed that the reconstituted suspension accelerated drug absorption (T_max = 2 h vs. 3 h for commercial capsules) and achieved a higher peak concentration (C_max = 3.19 vs. 2.82 μg/mL), with a comparable area under the plasma concentration-time curve (AUC_0-12 h). This RAB formulation provides an alternative strategy to enhance swallowing safety and dosing convenience in vulnerable patient.