ADVANCES IN ORAL NANOSUSPENSION TECHNOLOGY: FORMULATION APPROACHES, CHARACTERIZATION AND RECENT APPLICATIONS

Nanosuspensions are submicron colloidal dispersions of poorly water-soluble drug particles stabilized by suitable surfactants or polymers. They have emerged as an effective drug delivery approach to overcome the challenges associated with poor aqueous solubility, low dissolution rate, and limited bioavailability of many pharmaceutical compounds. By reducing drug particle size to the nanometre range, nanosuspensions significantly increase surface area, resulting in enhanced saturation solubility, faster dissolution, and improved therapeutic efficacy. Various preparation methods, including media milling, high-pressure homogenization, precipitation, emulsion–solvent evaporation, solvent diffusion, and microemulsion techniques, have been successfully employed for laboratory-scale and industrial-scale production. The stability of nanosuspensions depends on appropriate formulation components such as stabilizers, surfactants, polymers, and cryoprotectants, which prevent particle aggregation and crystal growth. Nanosuspensions have demonstrated considerable potential in oral, parenteral, ocular, pulmonary, topical, buccal, nasal, transdermal, and brain-targeted drug delivery systems by improving drug absorption, bioavailability, and site-specific targeting while minimizing adverse effects. Furthermore, their adaptability for surface modification and incorporation into solid dosage forms broadens their pharmaceutical applications. Despite significant advancements, challenges related to long-term stability, redispersibility, large-scale manufacturing, and regulatory acceptance remain. Overall, nanosuspensions technology represents a promising strategy for enhancing the delivery and therapeutic performance of poorly soluble drugs and continues to be an important area of pharmaceutical research and development.