Ampule workshop of a pharmaceutical factory produces the procaine hydrochloride solution. This solution is stabilized by adding:

Answer options

1. 1,5 g of amino-propylene glycol
2. 0,1 mol/l of hydrochloric acid solution
3. 20,0 of sodium hydrogen carbonate
4. 0,1 mol/l of sodium hydrogen carbonate solution
5. 0,1 mol/l of sodium hydroxide solution