Method and composition for preserving sodium nitroprusside solutions

1. A method to extend a shelf life of a sodium nitroprusside solution comprising: dissolving about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside in about seventy-five parts by weight of a polyethylene glycol.

2. The method of claim 1 , comprising: dissolving 3 g of 2-hydroxybenzyl alcohol and 1.5 g sodium nitroprusside in 100 ml of polyethylene glycol 300 at about 60° C.

3. The method of claim 1 , wherein said polyethylene glycol comprises a polyethylene glycol 300.

4. The method of claim 1 , wherein said polyethylene glycol comprises a PEG-400.

5. The method of claim 1 , wherein said polyethylene glycol comprises a PEG-1000.

6. A composition for preserving a sodium nitroprusside solution comprising: about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside dissolved in about seventy-five parts by weight of a polyethylene glycol.

7. The composition of claim 6 , comprising: 3 g of 2-hydroxybenzyl alcohol and 1.5 g sodium nitroprusside dissolved in 100 ml of polyethylene glycol 300 at about 60° C.

8. The composition of claim 6 , wherein said sodium nitroprusside solution is capable of catalyzing an indophenol monochloramine reaction.

9. A composition for preserving a sodium nitroprusside solution comprising: about two parts by weight of a 2-hydroxybenzyl alcohol and about one part by weight of a sodium nitroprusside dissolved in a component comprising a liquid selected from the group consisting of polyethylene glycol, ethane-1,2-diol, propane-1,2-diol, a polymer with a H—(O—CH2—CH2)n-OH structure either linear or cross-linked, and a glycopolymer.

10. The composition of claim 9 , wherein the liquid is propane-1,2-diol, and the component comprises up to about 70% water by volume.

11. The composition of claim 9 , wherein the component comprises approximately 30% propane-1,2-diol and approximately 70% water by volume.

12. A composition for preserving a sodium nitroprusside solution comprising: a 2-hydroxybenzyl alcohol and a sodium nitroprusside dissolved in a mixture of propane-1,2-diol and water.

13. The composition of claim 12 , wherein the mixture comprises approximately 30% propane-1,2-diol and approximately 70% water by volume.

14. The composition of claim 13 , wherein the composition comprises approximately 1% sodium nitroprusside by weight.

15. The composition of claim 14 , wherein the ratio of the 2-hydroxybenzyl alcohol to the sodium nitroprusside is about two parts by weight to one part by weight.

16. The composition of claim 12 , wherein the composition comprises approximately 1% sodium nitroprusside by weight.

17. The composition of claim 16 , wherein the ratio of the 2-hydroxybenzyl alcohol to the sodium nitroprusside is about two parts by weight to one part by weight.

18. A method to extend a shelf life of a sodium nitroprusside solution comprising:

dissolving a 2-hydroxybenzyl alcohol and a sodium nitroprusside in a mixture of propane-1,2-diol and water.

19. The method of claim 18 , wherein the mixture comprises approximately 30% propane-1,2-diol and approximately 70% water by volume.

20. The method of claim 19 , wherein the composition comprises approximately 1% sodium nitroprusside by weight.

21. The method of claim 20 , wherein the ratio of the 2-hydroxybenzyl alcohol to the sodium nitroprusside is about two parts by weight to one part by weight.

22. The method of claim 18 , wherein the composition comprises approximately 1% sodium nitroprusside by weight.

23. The method of claim 22 , wherein the ratio of the 2-hydroxybenzyl alcohol to the sodium nitroprusside is about two parts by weight to one part by weight.