3-11. PRESERVATION OF SYRUPS
In some syrup, the high quantity of sucrose is sufficient to preserve them. Others
a. Temperature. Low temperature is the best method of preserving syrups.
Syrups should not be stored above 25 C (77 Fahrenheit).
b. Glycerin. Glycerin may be effective in preserving some syrup; especially,
those made with dextrose. A 30 percent concentration is sufficient to prevent microbial
vegetable extractives. Glycerin, although sweet, does not have the high palatability of
sucrose or dextrose.
c. Additives. Syrups may also be preserved by small concentrations of
additives such as methylparaben (0.05 to 0.25 percent), benzoic acid, or sodium
3-12. SYRUP, USP
a. Composition. Syrup, USP (simple syrup) contains 850 grams (gm) of
sucrose dissolved in a sufficient quantity of water to make the total volume of the
preparation measure 1000-ml, thus making the syrup 85 percent weight/volume (w/v) in
concentration, a concentration which is sufficient to inhibit mold growth.
b. Properties. Syrup, USP has a specific gravity of 1.313 (it weighs 1,313-gm
per 1000-ml). It should be stored in tight containers, preferably at a temperature not
exceeding 25 C. Syrup is actually bacteriocidal because it is so hypertonic that it
dehydrates organisms trying to live on it before they can grow or reproduce. That is,
because of its hypertonicity, fluid is withdrawn by osmosis from the microorganism until
it can no longer survive.
c. Uses. Syrup is a sweetening vehicle and a pharmaceutical necessity for the
preparation of much official and nonofficial syrup and other preparations.
3-13. OTHER SYRUPS
Some syrup is more useful in masking certain kinds of tastes than others. For
example, Glycyrrhiza Syrup, USP (licorice syrup) is useful in masking salty and bitter
tastes. Three of the most popular syrups for masking a variety of tastes are Cherry
Syrup, USP; Raspberry Syrup, USP; and Cocoa Syrup, USP (cacao syrup).