In pharmaceutical development, pharmaceutical nanocrystals sized between 10 and 1000 nanometers have been found to hold promise in improving drug solubility. Since they comprise only the active pharmaceutical ingredient, nanocrystals have dramatically increased surface area-to-volume ratios, ensuring improved in vitro dissolution and solubility profiles. In view of their strengths and limitations, different production strategies have been reviewed: methods of size reduction such as wet milling and high-pressure homogenization; the bottom-up approaches of controlled precipitation and supercritical fluid technology; and efficient ways to stabilize nanocrystal formulations aided by excipients like surfactants and polymers. Techniques used in this characterization of nanocrystals include size analysis, surface-charge measurement, and assessment of crystalline structure. The routes of administration, such as oral, injectable, inhaled, and topical application, are reviewed alongside commercially successful products and clinical trials. This work reviews dynamic regulatory scenarios and current challenges of large-scale production, long-term stability, and nanotoxicity evaluation. In addition, it addresses the emerging trends in nanocrystal technology in the field of personalized medicine, targeted drug delivery, and theranostic approaches associated with how nanocrystals can help optimize the outcome of a patient in drug delivery systems.