Hi everyone,
We are having trouble with the solution's pH. With a solution of 50g of sodium ascorbate, purity of 100% according to the technical sheet (we buy the powder in a compounding pharmacy), on 500ml of normal saline we get a 6,0 pH. Impossible for us to reach the 7,4 or superior that Carthcart, Levy, eDOC and others reach.
What is going wrong?
If we use water for injection we have the same problem. Both, water for injection and NS are slightly acid, over 5,5 pH. It seems impossible that 50g of sodium ascorbate will rise the 5,5 pH of 500ml of NS or wfi to 7,5. There is some mathematical expressions to calculate this, but I can ensure that because I was making trials with a pH tester on different quantities of NS, wfi, Sodium ascorbate an sodium bicarbonate, and I can conclude that a concentration of over 10% w/w of sodium ascorbate on NS or wfi do not reach a total pH 7,0 by far.
With this pH the injection, over time, becomes harmful in veins, and we cannot inject all the vitamin C that we want.
We have not added to the solution calcium gluconate yet. We hope that the gluconate will alkalize de solution but we suppose that one gram hardly will raise the solution's pH.
Can you help us?
Regards.