Overview
Digoxin is a purified cardiac glycoside extracted from the leaves of Digitalis lanata, historically known as foxglove. It has been a cornerstone in managing heart rhythm disorders and congestive heart failure since the 18th century. The compound works by inhibiting the sodium-potassium ATPase pump, leading to increased intracellular calcium and enhanced myocardial contraction. In modern medicine, digoxin is prescribed for its inotropic and chronotropic effects, particularly in patients with atrial fibrillation or systolic heart failure. Despite newer alternatives, it remains clinically relevant due to its cost-effectiveness and well-understood pharmacokinetics.
Physical and Chemical Properties
Digoxin appears as a white, odorless crystalline powder with a bitter taste. It is stable under normal conditions but degrades when exposed to prolonged light or humidity. The compound is sparingly soluble in water but dissolves readily in polar organic solvents like ethanol or chloroform. Its molecular structure includes a steroid nucleus linked to a lactone ring and three digitoxose sugars, which are critical for its biological activity. The glycosidic bond is susceptible to hydrolysis under acidic conditions, necessitating careful storage and handling.
Main Applications
Digoxin's primary use is in controlling ventricular rate in atrial fibrillation and flutter, where it slows AV node conduction. It also improves symptoms in chronic heart failure by increasing cardiac output. Off-label applications include fetal tachycardia management and certain endocrine disorders. In B2B markets, digoxin is supplied to pharmaceutical manufacturers for tablet or injection formulations. It is often compounded with excipients like lactose or microcrystalline cellulose to ensure precise dosing in final products.
Safety and Storage
Due to its narrow therapeutic index (0.5–2 ng/mL serum concentration), digoxin requires meticulous dosing and monitoring. Toxicity manifests as gastrointestinal distress, visual disturbances, and life-threatening arrhythmias. Antidotes like digoxin immune fab are available for severe cases. Bulk digoxin should be stored in airtight containers with desiccants, away from direct sunlight. Stability testing indicates a shelf life of 3–5 years when stored below 25°C. Suppliers must provide certificates of analysis detailing residual solvents and heavy metal content.
B2B Procurement Guide
When sourcing digoxin, prioritize suppliers with GMP certification and auditable supply chains. Key specifications include HPLC purity ≥98%, low endotoxin levels (<0.5 EU/mg), and compliance with USP/EP monographs. Batch-specific COAs should confirm identity via IR spectroscopy and mass spectrometry. Pricing varies by quantity and purity; bulk orders (1 kg+) typically cost 15–30% less per gram. Consider regional regulations—some countries require import permits for cardiac glycosides. Lead times average 4–8 weeks due to stringent quality controls.