A prescription of a mixture consisting of trinatrium citrate and citrate seems to me peculiar. What ingredients should I use?

Twice citrate is illogical. Citric acid is believed to be used. There is a commercial product CYTRA-2, which is an oral solution, which contains the combination Na3citraat and citric acid. It is used as an alkalinizing medicine. After citrate is metabolized to bicarbonate, thus working as a systemic   alkalinizing product. The solution is useful for alkaline keeping of urine over a longer period and for the treatment of acidosis. Possibly neutralistaemia of stomach acid.