Advances in Self-Emulsifying Drug Delivery Systems: Focus on Pellet-Based Formulations

Self-emulsifying drug delivery systems (SEDDS) have emerged as a promising approach to enhance the solubility and oral bioavailability of poorly water-soluble drugs. Among these, self-emulsifying pellets represent a novel solid dosage form that combines the advantages of both SEDDS and multiparticulate systems. This review focuses on the formulation, evaluation, and optimization of self-emulsifying pellets, with particular attention to their application for delivering Venlafaxine Hydrochloride, a BCS Class I drug with high solubility and permeability. Key formulation components, including oils, surfactants, and co-surfactants, are discussed along with the role of excipients such as microcrystalline cellulose and lactose monohydrate in improving pellet properties. Various techniques employed in the preparation of pellets, including extrusion–spheronization, are critically analyzed. The review also highlights different characterization methods such as dissolution testing, droplet size analysis, and surface morphology studies that ensure product quality and performance. Optimization strategies using design of experiments (DoE) are explored for achieving desired drug release profiles. The advantages, limitations, and future prospects of self-emulsifying pellets as a drug delivery platform are also presented, emphasizing their potential for industrial scalability and patient compliance.