Determination of psoralen and plumbagin from its polyherbal oil formulations by an HPTLC densitometric method.

Many polyherbal oil formulations in Indian and Chinese traditional systems of medicine used for control of skin diseases contain seeds of Psoralea corylifolia and roots of Plumbago zeylanica L. Psoralen and plumbagin are the reliable markers for Ps. corylifolia and Pl.