Product Details

Tetramisole hydrochloride, chemically known as (±)-2,3,5,6-tetrahydro-6-phenylimidazo[2,1-b]thiazole hydrochloride, is a white to off-white crystalline powder with a molecular formula of C11H12N2S·HCl and a molecular weight of 240.75 g/mol. This chiral compound exists as a racemic mixture of its dextro- and levorotatory isomers, with the biologically active L-form (levamisole) demonstrating significantly greater anthelmintic activity than its D-isomer counterpart. The hydrochloride salt form enhances water solubility (>50 mg/mL) while maintaining stability under normal storage conditions (room temperature, protected from light and moisture). Structural characterization reveals an imidazothiazole ring system with a phenyl substituent at the 6-position, which is crucial for its pharmacological activity. Analytical methods including HPLC typically show ≥98% purity with specified impurities such as 2-imino-3-(2-mercaptoethyl)-5-phenylimidazolidine limited to ≤0.5%. The compound exhibits characteristic UV absorption maxima at 220 nm and 280 nm in acidic solutions, while FTIR spectroscopy confirms the presence of key functional groups through N-H stretching at 3400 cm¹ and aromatic C=C vibrations at 1600 cm¹. Quality control parameters include strict limits for heavy metals (<10 ppm), residual solvents (meeting ICH guidelines), and microbial contamination (<100 CFU/g) to ensure pharmaceutical-grade standards. The hydrochloride salt demonstrates excellent thermal stability with a melting point range of 266-268°C (with decomposition) and maintains stability across a pH range of 3.0-6.5 in aqueous solutions.

Application&Function

Tetramisole hydrochloride functions primarily as a broad-spectrum anthelmintic agent, with its L-isomer (levamisole) being particularly effective against nematode parasites through nicotinic acetylcholine receptor agonism at the neuromuscular junction, causing spastic paralysis and subsequent expulsion of parasites. While initially developed for veterinary use against gastrointestinal roundworms in livestock, its immunomodulatory properties led to human medical applications, particularly as an adjuvant therapy in colorectal cancer treatment and as an immunostimulant for recurrent aphthous ulcers and rheumatoid arthritis. The compound demonstrates unique dose-dependent biphasic effects on the immune system, enhancing cell-mediated immunity at lower doses while potentially suppressing immune function at higher concentrations. Formulation challenges have been addressed through development of soluble powders, oral drenches, and injectable solutions, with stability studies confirming 24-month shelf life in proper storage conditions. Safety considerations include potential cholinergic side effects at therapeutic doses and rare but serious hematological effects (agranulocytosis) with prolonged human use, leading to restricted medical applications in many countries. Current veterinary applications emphasize its cost-effectiveness and broad-spectrum activity against economically important parasites like Haemonchus, Ostertagia, and Trichostrongylus species in ruminants.