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THE DETERMINATION and STABILITY OF SODIUM NITROPRUSSIDE IN AQUEOUS SOLUTIONS (DETERMINATION and STABILITY OF SNP)
Author(s) -
Vesey C.J.,
Batistoni G.A.
Publication year - 1977
Publication title -
journal of clinical pharmacy and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.622
H-Index - 73
eISSN - 1365-2710
pISSN - 0269-4727
DOI - 10.1111/j.1365-2710.1977.tb00080.x
Subject(s) - absorbance , sodium nitroprusside , chemistry , aqueous solution , chromatography , saline , nuclear chemistry , anesthesia , medicine , organic chemistry , nitric oxide
Summary Addition of sodium nitroprusside (SNP) to a solution of sulphide at a pH above 12 produces a red‐purple colour with maximum absorbance at 540nm. This colour reaction was used for the assay of SNP solutions (2040mgl ‐1 ) and to investigate changes in SNP concentration during storage. Protected from light undiluted injection solutions (10g SNP 1 ‐1 ) were stable for more than two years. Foil‐wrapped infusion solutions (ca. 200 mg SNP 1 ‐1 ) in 0.9% saline or 5% dextrose were stable for at least seven days, but on exposure to light the SNP concentration fell whilst the free cyanide content rose exponentially until the solutions turned blue. A 45% decrease in SNP concentration and an HCN concentration of 6mgl‐resulted from 2h exposure to sunlight. Infusion solutions are best prepared in 5% dextrose and if used in direct daylight, or in diffuse daylight and/or artificial light for longer than 3 h, should be foil wrapped.