Can you give me the composition of a syrup with isoniazid? Is this long lasting?

isoniazid 1 g
na EDTA 0.1 g
after citrate 75 mg
Glycerin 20 g
Contrac Parabene solution NF 1 G
Freshly boiled water up to 105 g

This solution should indicate a PH 5 à 6. The shelf life is 3 months with KT and 6 months in the refrigerator.