Abstract
In fact pyridoxine (PN) in a commercial internal solution (injection) was stable to light, but became unstable by dilution with distilled water or infusion fluid. PN, pyridoxamine, pyridoxamine 5'-phosphate, and pyridoxal 5'-phosphate were found to be relatively stable to light in the concentrated solutions (>25mM), but unstable in dilute solutions (<0.5mM). The results suggest that possible photodecomposition should be considered in handling dilute solution of vitamin B_6 for medical use. The photodecomposition of PN was slow in polyethylene container for the internal solution which had poor light transmittance, but was fast in polypropylene or glass container for the infusion fluid which showed high light transmittance.
