Patent ID: 7622441

Claim:
A pharmaceutical composition comprising: codeine; and a carrier covalently bound to the codeine in a manner that renders the codeine pharmacologically inactive or provides reduced pharmacological activity compared to codeine alone when administered parenterally, but provides pharmacologically effective amounts of codeine when administered orally; wherein the carrier is a peptide selected from the group consisting of Gly-Gly-Leu, Gly-Gly-Glu, Gly-Gly-Ile, Gly-Gly-Phe, Gly-Leu-Ile, Gly-Phe-Ile, Gly-Leu-Leu, Gly-Phe-Leu, Leu-Pro-Glu, Leu-Pro-Leu, Leu-Pro-Phe, Pro-Pro-Glu, Pro-Pro-Leu, Pro-Pro-Ile, Pro-Pro-Phe, Glu-Glu-Glu, Leu-Leu-Glu, Leu-Leu-Leu, Gly 4 -Leu (SEQ ID NO: 1), Glu 5 (SEQ ID NO: 2), Gly 4 -Ile (SEQ ID NO: 3), Gly 4 -Phe (SEQ ID NO: 5), Glu 2 -Gly 2 (SEQ ID NO: 6), Glu 2 -Gly 2 -Leu (SEQ ID NO: 8), or Glu2-Gly2-Ile (SEQ ID NO: 9); wherein the hydroxyl group of codeine is bound to the C-terminus of the carrier.