Radiopharmaceutical scanning agents

Claim 2

A dispersion useful in forming an injectable radiopharmaceutical scanning agent comprising a stannous sulfur colloid dispersed in an aqueous buffer solution.

Claim 3

A dispersion according to claim 1 wherein said dispersion is buffered to a pH of 3 to 4 at 25° C.

Claim 4

A dispersion according to claim 2 wherein said dispersion contains an effective amount of a stabilizing agent to stabilize said particles in said buffer solution, said dispersion having an average colloid particle size of from about 1 millimicron to about 1 micron.

Claim 5

A dispersion useful in forming an injectable radiopharmaceutical scanning agent prepared by the method comprising a. forming a dispersion containing a sulfur colloid by reacting in an aqueous medium a thiosulfate with a pharmaceutically acceptable acid, b. interacting a pharmaceutically acceptable stannous salt with the dispersion of (a) and thereafter buffering the resulting dispersion.

Claim 6

A dispersion useful in forming an injectable radiopharmaceutical scanning agent prepared by the method comprising a. forming a dispersion containing a sulfur colloid by reacting in an aqueous medium a thiosulfate with a pharmaceutically acceptable acid, b. interacting a pharmaceutically acceptable stannous salt with the dispersion of (a) and thereafter buffering the resulting dispersion.

Claim 7

A dispersion according to claim 4 which is buffered to a pH of 3 to 4.

Claim 8

A dispersion according to claim 5 wherein said dispersion contains an effective amount of a stabilizing agent to stablize said particles of said dispersion in said buffer solution, said dispersion having an average colloid particle size of from about 1 millimicron to about 1 micron.

Claim 9

A dispersion according to claim 6 wherein said stabilizing agent is glycine.

Claim 10

An injectable radiopharmaceutical scanning agent comprising the dispersion of claim 4 labelled with technetium-99m.

Claim 11

A method for preparing a radiopharmaceutical scanning agent which comprises labelling the dispersion of claim 4 with technetium 99m.

Claim 12

method for preparing a dispersion of a stannous sulfur colloid in an aqueous buffer solution which is useful in forming an injectable radiopharmaceutical scanning agent comprising a. forming a dispersion containing a sulfur colloid by reacting in an aqueous medium a thiosulfate with a pharmaceutically acceptable acid, b. interacting a pharmaceutically acceptable stannous salt with the dispersion of (a) to form a dispersion containing a stannous sulfur colloid and buffering said dispersion contaning said stannous sulfur colloid.

Claim 13

method for preparing a dispersion of a stannous sulfur colloid in an aqueous buffer solution which is useful in forming an injectable radiopharmaceutical scanning agent comprising a. forming a dispersion containing a sulfur colloid by reacting in an aqueous medium a thiosulfate with a pharmaceutically acceptable acid, b. interacting a pharmaceutically acceptable stannous salt with the dispersion of (a) to form a dispersion containing a stannous sulfur colloid and buffering said dispersion contaning said stannous sulfur colloid.

Claim 14

A method according to claim 10 wherein a stabilizer is added to stabilize said stannous sulfur colloid particles.

Claim 15

A method according to claim 11 wherein said stabilizer is glycine.

Claim 16

A method according to claim 12 wherein said dispersion is labelled with technetium-99m.

Claim 17

A method according to claim 11 wherein said thiosulate is sodium thiosuflate said stannous salt is stannous chloride and said acid is hydrochloric.

Claim 18

An injectable radiopharmaceutical scanning agent comprising a technetium-99m labelled sulfur colloid to which stannous ions are attached dispersed in an aqueous buffer solution.

Claim 19

An injectable radiopharmaceutical scanning agent comprising a technetium-99m labelled sulfur colloid to which stannous ions are attached dispersed in an aqueous buffer solution.

Claim 20

A scanning agent according to claim 8 wherein said dispersion contains an effective amount of a stabilizer to stabilize said particles in said buffer solution, has a pH of 3 to 4 and has an average particle size of from about 1 millimicron to about 1 micron.

Claim 21

A scanning agent according to claim 16 wherein said stabilizer is glycine.

Claim 22

In a method for imaging the reticuloendothelial system wherein a scintillation scanning agent is intravenously injected and thereafter a scan is made, the improvement comprising utilizing as the scintillation scanning agent the radiopharmaceutical scanning agent of claim 8.

Claim 23

In a method for imaging the reticuloendothelial system wherein a scintillation scanning agent is intravenously injected and thereafter a scan is made, the improvement comprising utilizing as the scintillation scanning agent the radipharmaceutical scanning agent of claim 16.

Claim 24

In a method for imaging the reticuloendothelial system wherein a scintillation scanning agent is intravenously injected and thereafter a scan is made, the improvement comprising utilizing as the scintillation scanning agent the radiopharmaceutical scanning agent of claim 17.