An oral liquid made from hydroxychloroquine will have an extremely bitter taste. No formal stability studies have been located. If you are using the sulphate salt this is freely soluble in water so there is no real need for a suspending agent such as methylcellulose. A base of 40 % glycerol (sweet but no tooth decay) and water with 0.1 % parabens could be used.

This simple mixture can be added to the child's favorite drink immediately prior to administration. A range of flavours could be tried in an attempt to make the mixture palatable.

There is also a formula in "Trissel's Stability of Compounded Formulations" from an article by Pesko in Am Druggist 1993:207:57. A 50:50 mixture of Ora-Plus and water was used for the base and a 30 day expiry date suggested in the absence of stability testing.