Development of orodispersible wafer-based delayed-release omeprazole systems for pediatric compounding

Omeprazole (OMZ) is one of the most frequently compounded active pharmaceutical ingredients for pediatric use. Despite the availability of licensed pediatric formulations in some countries, extemporaneous oral suspensions remain widely used in hospital pharmacies, although their limited chemical stability, short shelf life, and need for specific storage conditions may complicate routine use. This study aimed to develop a child-appropriate solid alternative based on a hybrid lipid-wafer platform combining gastro-resistant OMZ microparticles with an orodispersible matrix. Orodispersible wafers (ODWs), composed of pectin, κ-carrageenan, and maltodextrins, were produced by lyophilization, yielding highly porous matrices with low residual moisture (2.74%) and rapid oral disintegration. To protect OMZ during gastric exposure, two encapsulation strategies were investigated: calcium alginate-zein beads and lipid microparticles (LMPs). Morphology, particle size, drug loading, encapsulation efficiency, and solid state were characterized, and drug release was evaluated in gastrointestinal buffers and pediatric biorelevant media. Trimyristin-based LMPs showed the most favorable performance, limiting OMZ exposure to the acidic environment and providing controlled intestinal release consistent with Higuchi kinetics. Their incorporation into ODWs yielded a solid unit containing approximately 2.5 mg OMZ. Importantly, OMZ content remained unchanged for up to six months, with comparable release profiles at t₀ and after storage, including at room temperature. Overall, the proposed hybrid lipid-wafer platform provides a stable, child-appropriate solid dosage form to OMZ delivery and represents a promising formulation strategy for further development in suitably equipped hospital pharmacy compounding settings.