Method of preparing a botanical extract that includes contacting a raw botanical with a solvent having a dielectric constant ranging from about 2.3 to about 25 and allowing the mixture to reside for a sufficient time to obtain a crude extract; filtering out remaining raw botanical and evaporating the solvent from the crude extract under reduced pressure to obtain a dried crude extract; washing the dried crude extract with a polar solvent having a dielectric constant of no less than 30, heating the resulting mixture, and allowing to cool to ambient; collecting a filtrate from the above cooled mixture; washing the collected filtrate with a non-polar solvent having a dielectric constant of no more than 2.0; and filtering and drying the mixture to obtain the botanical extract.