Nanosuspensions For Enhancing Drug Solubility: Formulation Strategies and Stability Challenges

The poor solubility of several active pharmaceutical ingredients is a major challenge that compromises bioavailability and pharmacological responses. Nanosuspensions have emerged as an effective technology for enhancing drug solubility and the dissolution rate of the drug. This review critically explores the formulation strategies, including bottom-up, top-down, and combinative techniques, and solidification methods such as spray drying and lyophilization. A detailed evaluation of key stability challenges—aggregation, Ostwald ripening, and crystal growth—is provided, along with mechanistic insights into electrostatic, steric, and electrosteric stabilization. The manuscript emphasizes how stabilizer type and concentration significantly influence the physical stability and performance of nanosuspensions. Characterization parameters such as particle size, zeta potential, saturation solubility, and crystallinity transitions are discussed to ensure optimal formulation quality. Additionally, recent advancements in route-specific nanosuspension applications and selected clinical trial data underscore the evolving relevance of this approach. The review concludes by outlining future directions for enhancing long-term stability and expanding therapeutic applications.