Microencapsulation of Ranitidine Hydrochloride for Controlled Release Drug Formulation

Abstract

The present study explored the microencapsulation of ranitidine hydrochloride to develop a controlled-release formulation aimed at improving bioavailability, reducing dosing frequency, and enhancing drug stability. Ranitidine, a H₂-receptor antagonist, is commonly used in the treatment of gastrointestinal disorders such as acid reflux, peptic ulcers, and Zollinger–Ellison syndrome. However, its conventional formulations are limited by a short half-life, poor stability, and the potential formation of N-nitrosodimethylamine (NDMA), a probable human carcinogen. To overcome these limitations, microencapsulation was employed using polymers such as Hydroxypropyl Methylcellulose (HPMC) and Microcrystalline Cellulose (MCC 102). The drug–polymer mixture was prepared using the extrusion–spheronization technique, followed by spray drying and pelletization. Various formulations were optimized by altering the drug-to-polymer ratio and solvent system (isopropyl alcohol and water). The prepared microcapsules and pellets were evaluated for physicochemical properties, including particle size, morphology, encapsulation efficiency, zeta potential, and surface characteristics using UV–Visible spectrophotometry, dynamic light scattering (DLS), and scanning electron microscopy (SEM). In vitro dissolution studies demonstrated a sustained drug release profile, which followed zero-order and Higuchi kinetic models, indicating controlled drug release behavior. The microencapsulation approach effectively minimized the degradation of ranitidine and ensured a more consistent release under simulated gastric conditions. Compatibility and stability studies further confirmed that HPMC and MCC-based formulations provided enhanced protection against hydrolysis and environmental stress. Overall, the findings suggest that microencapsulation is a promising strategy for reformulating ranitidine, offering improved therapeutic efficacy, controlled drug release, and better patient compliance. This study also provides a foundation for extending microencapsulation approaches to other drugs with short half-lives or stability concerns.