Propylene Glycol Alginate Sodium Sulfate (PSS): The First Oral Heparinoid Marine Drug—A Pharmacological and Clinical Review

Propylene glycol alginate sodium sulfate (PSS) is the first oral heparinoid marine drug, derived from brown algal alginic acid and marketed in 1986. Its core pharmacology, including anticoagulation, lipid-lowering, microcirculation improvement, and neuroprotection, makes it an affordable oral option for chronic ischemic cardiovascular and cerebrovascular diseases. Pharmacological studies have also revealed anti-inflammatory, anti-fibrotic, anti-metastatic, and FGF/FGFR-activating effects. Notably, these activities can be independently modulated by molecular weight and M/G ratio, enabling activity-specific structural optimization, guiding the development of safer derivatives. This review summarizes PSS’s R&D, mechanisms, clinical applications, and safety, aiming to inform precision medication strategies and inspire similar drug development.