Nanocrystals (NCs) have emerged as an effective strategy for enhancing the bioavailability of poorly water-soluble drugs. By reducing particle size, NCs increase the surface area of the drug, thereby improving its dissolution rate and absorption. This approach addresses key challenges associated with the poor aqueous solubility of many therapeutic agents, leading to improved drug delivery and therapeutic efficacy. NCs offer several advantages, including high drug loading capacity, enhanced physical stability, and the potential for sustained or targeted release, making them a valuable tool in pharmaceutical formulations. This chapter discusses key strategies for stabilizing NCs, including the use of stabilizers that prevent aggregation and improve physical stability. It details commonly employed stabilizing agents, such as ionic surfactants and polymers, along with their mechanisms of action. Additionally, characterization techniques such as dynamic light scattering (DLS), laser diffraction (LD), and zeta potential analysis are discussed in terms of their role in assessing particle size, size distribution, and surface charge of NCs. Finally, the chapter highlights how these methods support the optimization of drug formulations, enhancing their performance in terms of dissolution, bioavailability, and overall therapeutic effectiveness.