Which product to use for the pH setting of a Gabbroral suspension instead of NaOH?

The suspension is prepared as follows  :   R/Gabbroral 250 mg 16 tabl; glycerol 7.5 g;   after citrate 0.15 g;   NaOH 20% ph 7.9; Banana aroma     QS;     Sir. Simplex AD 150 ml

S/3x5 ml/day

There   can also be chosen for apricots or raspberry aroma?

NAOH is lacking   often and in this case the pH can be set with a 10 or 20% sodium carbonate solution