A Comprehensive Monograph on Sodium Selenite: Chemical Properties, Pharmacological Profile, and Clinical Significance

1.0 Introduction and Compound Identification

1.1 Overview of Sodium Selenite as an Inorganic Selenium Source

Sodium selenite is an inorganic salt that serves as a primary source of the essential trace element selenium. It is utilized across a spectrum of applications, ranging from a nutraceutical in dietary supplements to a therapeutic agent in clinical and veterinary medicine, and as a component in industrial processes.[1] As a chemical entity, it is defined by the duality of its biological role: selenium is indispensable for human health at low, physiological concentrations, yet it exhibits significant toxicity at higher doses.[4] This narrow therapeutic index is a central theme in its pharmacology and toxicology. In medicine, sodium selenite is investigated for its potential antineoplastic activity, a function that contrasts sharply with its role in maintaining cellular homeostasis, setting the stage for a complex, dose-dependent mechanism of action.[1]

1.2 Comprehensive Chemical and Physical Profile

The anhydrous form of sodium selenite is a well-characterized inorganic compound. It is a white or colorless crystalline solid, though it may also be supplied as a beige powder.[1] There is some discrepancy in the literature regarding its hygroscopic nature; while several sources describe it as a hygroscopic solid that readily absorbs moisture from the air, at least one supplier datasheet indicates it is not.[1] This variability may be attributable to differences in sample purity or experimental conditions and underscores the importance of controlled storage for maintaining the compound's integrity.