Used primarily as a selective Rho-kinase (ROCK) inhibitor, hydroxyfasudil hydrochloride is valuable in research related to cardiovascular diseases. It helps relax vascular smooth muscle, making it useful in studies on hypertension, cerebral vasospasm, and ischemic stroke. It has shown potential in improving blood flow and reducing vascular resistance in experimental models. Additionally, it is investigated for its neuroprotective effects, particularly in conditions involving neuronal damage due to oxidative stress or inflammation. Its ability to cross the blood-brain barrier enhances its utility in central nervous system research. It is also explored in pulmonary hypertension, glaucoma, and renal injury models due to its vasodilatory and anti-fibrotic properties.