Claims for Patent: 3,863,004

Summary for Patent: 3,863,004

Title:	DENATURED MACROPROTEIN WITH DIVALENT TIN FOR TAGGING WITH TECHNETIUM-99M AND METHOD OF PREPARATION
Abstract:	An improved composition suitable for tagging with technetium-99m and use in lung scanning procedures consists essentially of an injectable suspension in buffer solution of particles of a denatured macroprotein having divalent tin bound thereto. The macroprotein has a molecular weight of at least about 20,000. A method for preparing the injectable suspension by treating macroaggregates or microspheres of a denatured macroprotein with a solution containing divalent tin ions is also provided.
Inventor(s):	Wolfangel; Robert G. (St. Louis, MO)
Assignee:	Mallinckroft Chemical Works (St. Louis, MO)
Application Number:	05/236,159
Patent Claims:	1. A composition suitable for rapid tagging with technetium-99m and use in lung scanning procedures consisting essentially of an injectable suspension in a buffer solution of particles of denatured macroprotein having divalent tin bound thereto, said macroprotein having a molecular 2. A composition as set forth in claim 1 wherein the pH of said buffer solution is approximately the isoelectric pH of said denatured 3. A composition as set forth in claim 1 wherein said macroprotein 4. A composition as set forth in claim 1 wherein the size of the particles 5. A composition as set forth in claim 4 wherein the mean size of said 6. A composition as set forth in claim 1 including macroprotein particles 7. A composition as set forth in claim 1 wherein the buffer solution contains between about 8 % and about 16 % by weight of an antiagglomerating agent selected from the group consisting of propylene 8. A process for preparing a buffered injectable suspension of particles of denatured macroprotein suitable for rapid tagging with technetium-99m and use in lung scanning procedures comprising the steps of: contacting particles of a denatured macroprotein with a solution containing a water-soluble salt of divalent tin causing divalent tin to be bound to said macroprotein; washing the macroprotein having divalent tin bound thereto with a buffer solution; and thereafter suspending in a buffer solution the macroprotein having divalent 9. A process as set forth in claim 8 wherein said macroprotein is human 10. A process as set forth in claim 8 wherein said solution containing 11. A process as set forth in claim 10 wherein said solution contains 12. A process as set forth in claim 8 wherein said macroprotein is in the 13. A process as set forth in claim 8 wherein said macroprotein is in the 14. A process as set forth in claim 8 wherein said macroprotein is prepared by precipitating denatured macroprotein in an acid medium at a pH approximately the isoelectric pH of said protein.