AzaSol is the first water soluble powdered azadirachtin product developed for superior biologically-based insect control. AzaSol is a high-potency powder thatâ€™s water soluble, solvent-free, and shelf stable for more than two years. Itâ€™s intended for use indoors and out, and can be applied via soil drench, injection or spray. Studies show azadirachtin, derived from neem plants, to be a highly effective broad spectrum biological insect control and repellent that provides protection from insects ranging from annual bluegrass weevils to whiteflies. 6 oz per 50 gal. of water.