We need to make cimetidine syrup 50 mg/ml for a child of 5 years.

  This product is soluble in water (50 mg/ml), with heat   as needed, are a clear, colorless to faint yellow   solution. The addition of dilute HCl has been reported to enhance the solubility of this product.   I suspect that for the concentration, you should prepare 16 ml HCl 1 M will not be necessary; maybe a few drops