Nanosuspension-based drug delivery systems for topical applications have gained significant attention due to their potential to enhance the bioavailability of hydrophobic drugs with poor solubility. These systems involve the dispersion of drug nanocrystals in a liquid medium, typically water, and offer advantages such as increased surface area, improved penetration, and targeted delivery to specific skin layers. Despite their promise, challenges remain in terms of stability, formulation design, and regulatory considerations. The review highlights the importance of nanosuspensions in addressing solubility issues, improving drug absorption, and enhancing cutaneous bioavailability, particularly for active ingredients with low to medium solubility. Various preparation methods, including high-pressure homogenization, media milling, and the smart crystal method, have been explored to produce nanosuspensions with optimal properties. Factors such as stabilizers, surfactants, and excipients play a crucial role in ensuring the stability and efficacy of nanosuspensions. Additionally, the review discusses the application of nanosuspensions in ocular, pulmonary, and dermal drug delivery, emphasizing their potential to improve drug penetration and systemic availability. However, limitations such as toxicity concerns and the need for further research on long-term effects and regulatory approval remain. Overall, nanosuspensions represent a promising approach for enhancing topical drug delivery, with ongoing research aimed at overcoming existing challenges and optimizing their performance.Nanosuspension-based drug delivery systems for topical applications have gained significant attention due to their potential to enhance the bioavailability of hydrophobic drugs with poor solubility. These systems involve the dispersion of drug nanocrystals in a liquid medium, typically water, and offer advantages such as increased surface area, improved penetration, and targeted delivery to specific skin layers. Despite their promise, challenges remain in terms of stability, formulation design, and regulatory considerations. The review highlights the importance of nanosuspensions in addressing solubility issues, improving drug absorption, and enhancing cutaneous bioavailability, particularly for active ingredients with low to medium solubility. Various preparation methods, including high-pressure homogenization, media milling, and the smart crystal method, have been explored to produce nanosuspensions with optimal properties. Factors such as stabilizers, surfactants, and excipients play a crucial role in ensuring the stability and efficacy of nanosuspensions. Additionally, the review discusses the application of nanosuspensions in ocular, pulmonary, and dermal drug delivery, emphasizing their potential to improve drug penetration and systemic availability. However, limitations such as toxicity concerns and the need for further research on long-term effects and regulatory approval remain. Overall, nanosuspensions represent a promising approach for enhancing topical drug delivery, with ongoing research aimed at overcoming existing challenges and optimizing their performance.