Chemical formula:B1aC48H74O14(R=C2H5) ,B1bC47H72O14(R=CH3) Molecular weight:B1a:874 B1b:860 Description:White or slightly yellow crystalline powder.Soluble in methanol,alcohol,ester,and insoluble in water. Action:Anti-parasite antibiotic.It can repel and kill nematode,hook-worm,worm insect,worm and acarid in the bodies of livestock and poultry.It is mainly used to treat domestic animals deseases of nematode,itch mite and parasitic insect. Specification:This productcontians not less than 93.0% of 22,23-Dihy-droavermectin B1a,and not less than97.0% of 22,23-Dihy-droavermectin B1(B1a+B1b). Packing:Tin 1kg,5kg Storage:Kept in a Well-closed container,protected from light and stored in a dry place. Expiry:2 years.