STROMECTOL® (Ivermectin) is a semisynthetic, anthelmintic
agent for oral administration. Ivermectin is derived from the avermectins,
a class of highly active broad-spectrum anti-parasitic agents isolated
from the fermentation products of Streptomyces avermitilis. Ivermectin
is a mixture containing at least 90% 5-O-demethyl-22,23-dihydroavermectin
A1a and less than 10 % 5-O-demethyl-25-de(1-methylpropyl)-22,23-dihydro-25-(1-methylethyl)
avermectin A1b, generally referred to as 22,23-dihydroavermectin
B1a and B1b or H2B1a and H2B1b,
respectively. The respective empirical formulas are C48H74O14
and C47H72O14, with molecular weights
of 875.10 and 861.07, respectively.
Ivermectin is a white to yellowish-white, nonhygroscopic, crystalline
powder with a melting point of about 155 C. It is insoluble in water
but is freely soluble in methanol and soluble in 95% ethanol.
STROMECTOL is available in 3-mg tablets and 6-mg scored tablets. Each
tablet contains the following inactive ingredients: microcrystalline cellulose,
pregelatinized starch, magnesium stearate, butylated hydroxyanisole, and
citric acid powder (anhydrous).