There are 2 problems I see then.
1) Since it is sensitive to light, wrapping the bottle in aluminum foil or something similar would benefit. Then refrigerate.
2) Several people are adding drops to their drinking water, including me. I normally don't drink an entire glass of water in one sitting. I carry it around with me, to remind me to fill it again when done. This will not be good for the longevity of sodium chloride in the water.