Can you notify me of the maximum shelf life of the Dakin solution?

There is a lot to write about the chloramine solution; First of all, I would like to say that I have included a more concentrated composition in my booklet Galenic Formularium. The booklet describes a 0.5% solution. I suspect that a higher concentration is proposed because of a better activity.  

In my search for data on the stability of the Carrel-Dakin solution I found a monograph in a Formularium of German hospital pharmacists.   Two concentrations are described:

1.0.1% use as disinfectant rinse fluid for mouth, bladder and vagina

2.2% use for wound cleansing.

The 0.1% solution is packaged in Brtuinrode bottles with a polyethylene or propylene stopper of 500 ml. This packaging will have a shelf life of 2 years if stored in the dark. For the 2% solution the same packaging is used but of only 200 ml. This bottle also gets a shelf life of 2 years. In the section shelf life, again is clearly referred to the packaging form!!

I would use the same rules for the solution described in the NF and in the Galenic Formularium