Functional Category
Antimicrobial preservative; antioxidant.
Applications in Pharmaceutical Formulation
3-Mercaptopropane-1,2-diol, also known as Monothioglycerol or thioglycerol is used as an antioxidant in pharmaceutical formulations, mainly in parenteral preparations.(1) Monothioglycerol is reported to have some antimicrobial activity.(2–4) It is also widely used in cosmetic formulations such as depilating agents. Therapeutically, monothioglycerol has been used in a 0.02% w/w aqueous solution to stimulate wound healing, and as a 0.1% w/w jelly in atrophic rhinitis.
Description
Monothioglycerol occurs as a colorless or pale-yellow colored, viscous, hygroscopic liquid with a slight odor of sulfide.
Stability and Storage Conditions
Monothioglycerol is unstable in alkaline solutions. Monothioglycerol should be stored in a well-closed container in a cool, dry place
Incompatibilities
Monothioglycerol can react with oxidizing materials.
Safety
Monothioglycerol is generally regarded as a relatively nontoxic and nonirritant material at the concentrations used as a pharmaceutical excipient. It is used in topical and injectable preparations. Undiluted monothioglycerol is considered a poison by the IP and IV routes; it has also been reported to be mutagenic.(5) LD50 (cat, IV): 0.22 g/kg(5) LD50 (mouse, IP): 0.34 g/kg LD50 (rabbit, IV): 0.25 g/kg LD50 (rat, IP): 0.39 g/kg