We have a doctor's question to prepare valaciclovir syrup.

In The Dutch Formularium, the following composition is described for a beverage of 20 mg/ml    

Valaciclovir   HCl 2.23 g; citric acid 0.84 g; Na2HPO4 12 aq 1.25 g; Glycerol 52 g   and water up to 100 ml  

Dissolve citric acid, Na2HPO4 12 aq   and Valaciclovir HCl   in approx. 40 ml freshly boiled and cooled purified water; mix this solution with the glycerin and fill with water to deliver 100 ml in a brown red bottle and in a cardboard box to protect from light.  

The use mine is kept for 3 months in the refrigerator but not in the freezer. Stored at room temperature below 25 °C = 1 month.  

Note:

1.de high dose will have to be delivered a reasonably large amount of beverage. Of course, the duration of therapy is taken into account.  

2. I cannot speak about the taste but I suspect that there is a possibility to add an artificial sweetener?