FDA approved veterinary or human pharmaceutical substances; FDA approved veterinary or human pharmaceutical substances used to compound a needed dosage form; USP NF or BP pharmaceutical grade substance used in a needed dosage form also includes compounded products from sources such as compounding pharmacies; Analytical grade bulk chemical used to compound a needed dosage form requires justification; Other grades and sources of substances requires justification; For new investigational drugs the grade and formulation is not optional, but the investigator and IACUC can verify health and safety issues described above stromectol achat For the quantification was used an LC MS system consisted of a Varian apparatus Varian Inc including a vacuum solvent degassing unit, two pumps 212 LC, a Triple Quadrupole MSD Mod