Advances in Hydrophilic Drug Delivery: Encapsulation of Biotin in Alginate Microparticles

Background: The encapsulation of hydrophilic drugs within microparticles has gained significant interest in drug delivery systems due to their potential to improve stability, bioavailability, and controlled release of therapeutic agents. Biotin, a water-soluble vitamin, presents challenges such as rapid degradation and limited membrane permeability, which constrain its therapeutic effectiveness. Objectives: This study aims to develop and characterize biotin-loaded microparticles formulated with alginate, Eudragit^® E100, and CaCl₂, and to evaluate their characterization and potential applications. Methods: The microparticles were produced using the external ionic gelation method, where alginate and CaCl₂ solutions were mixed under probe sonication. Eudragit^® E100 was added as a complexing agent. The optimized formulation was used to encapsulate biotin, and various experimental variables were screened to study their influence on the properties of the microparticles. Results: Biotin was encapsulated in alginate microparticles (size: 634 nm; polydispersity index: 0.26; zeta potential: -45 mV) with an encapsulation efficiency of 90.5%. In vitro release studies using vertical diffusion Franz cells demonstrated a controlled release profile following the Weibull kinetic model. Conclusions: Encapsulation techniques offer a promising approach to overcome the limitations of hydrophilic drug delivery. The biotin-loaded microparticles developed in this study have potential applications in both topical and oral formulations, providing controlled release and improved therapeutic efficacy, and illustrate the broader applicability of polymeric encapsulation systems for improving the delivery of labile, hydrophilic bioactives.