Oral Delivery of Hydrophilic Drugs to the Brain

A composition comprising a lipophilic derivative of a hydrophilic drug and an amphiphile compound for use in therapy wherein the composition is orally administered to the human or animal body. The invention includes derivatives such as palmitoylated Leucine[5]-Enkephalin and is useful in the treatment of schizophrenia, obsesity, pain and sleep disorders, psychiatric diseases, neurodegenerative conditions, brain cancers and infective diseases.