Syrup

Syrup

From a technical and scientific standpoint, the term "syrup" is also used to describe thick, often residual liquids containing substances besides sugars in solution.

For medicinal purposes, the syrup serves as a concentrated or saturated solution of refined sugar in distilled water. The "simple syrup" outlined in the British Pharmacopoeia involves dissolving 1 kg of refined sugar in 500 mL of boiling distilled water, then adding more boiling distilled water until the total weight reaches 1.5 kg. The syrup's specific gravity should measure 1.33, constituting a 66° Brix solution.

Medicated syrups are aqueous solutions containing sugar and at least one water-soluble active ingredient.

Sugar serves several purposes:

 • Preserving the final product
 • Masking the unpleasant taste of the active ingredient(s)
 • Enhancing flavor.

The sugar concentration must nearly reach but not exceed the super-saturation point, falling between 65 and 67% by weight. Lower sugar percentages make the syrup an ideal nutrient for yeast and other microorganisms, while sugar-saturated syrup can lead to crystallization of some sugar portions under fluctuating temperature conditions.

Additional excipients in syrups may include:

 • Sugar polyols like glycerol, maltitol, and sorbitol
 • Preservatives such as parabens and benzoates, and antioxidants like butylated hydroxytoluene (BHT) and sodium metabisulfite
 • Acids like citric acid to prevent sugar recrystallization
 • Buffering agents
 • Chelating agents like sodium ethylenediaminetetraacetic acid (EDTA)
 • Flavoring agents and enhancers
 • Coloring agents
 • Ethyl alcohol (3-4% by volume).

Syrups may also be sugar-free, with sugar substitutes like sugar polyols (e.g., glycerol, isomaltol, sorbitol) or artificial sweeteners (e.g., aspartame, neotame, sucralose, acesulfame potassium) mixed with thickening agents such as polyvinylpyrrolidone or polysaccharides like carrageenan, xanthan gum, and cellulose ethers. Sugar-free syrup does not contribute to dental caries.

Syrups are typically prepared using the following method:

 • Dissolve ingredients in purified water, with sugar generally added last due to its impact on water's solubilizing properties.
 • Actively heat and/or agitate until all ingredients dissolve. If any ingredient is sensitive to temperature, mixing should occur without heating.
 • Strain if necessary.
 • Add sufficient purified water to achieve the desired weight or volume.