1. PRINCIPLES OF COMPOUNDING
Terrick Andey
College of Pharmacy & Pharmaceutical Sciences
Florida A&M University
February 2013

2. SYRUPS
Definition: concentrated solutions of sugar in water or other aqueous liquid
Sugar typically used is sucrose
Syrup/Simple Syrup: concentrated (but not saturated) sucrose solution in Purified Water
Other ingredients: glycerin, sorbitol, alcohol
Medicated Syrup: when preparation contains added medicinal substances
Flavored Syrup: non-medicated syrup containing aromatic or flavored ingredients (for preparations for children)

3. SYRUPS Properties: Mask bitter or unpleasant taste of drugs
Examples: Glycyrrhiza syrup, Acacia Syrup USP, Raspberry Syrup USP
Syrup with sucrose concentration of 65 %w/w is bacteriostatic
When syrup or sucrose is overheated, it caramelizes

4. SYRUPS – Preparation Solution with heat Agitation without heat
Percolation

5. SYRUPS – Solution with Heat
Solution with Heat: method of choice for:
Non-volatile medications
Thermostable ingredients
Rapid preparation
E.g.: Syrup USP
Excessive heating of syrup results in formation of caramel
Caramelization: evidenced by yellow-to-brown coloring of syrup due to burning of sucrose

6. SYRUPS - Solution with Heat
Syrup USP
Rx:
Sucrose gm
Purified Water q.s. ad to ml
Procedure:
Heat approx. 60 ml of distilled water to boiling
Add sucrose in small amounts to hot water while stirring
Continue adding sucrose (in small portions) allowing each batch to dissolve before adding the next
Filter syrup into a graduate cylinder; rinse the beaker with hot distilled water, pass solution through filter to obtain desired volume

7. SYRUPS – Agitation without Heat
Useful were volatile agents are in formulation
Preparation is done in a bottle with a stopper twice the volume of syrup desired
Examples: Guaifenesin Syrup USP, Codeine Linctus

8. SYRUPS – Agitation without Heat
Codein Linctus:
Rx:
Codeine Phosphate 3 gm
Compound Tartrazine Solution 10 ml
Benzoic Acid Solution 20 ml
chloroform Spirit 20 ml
Purified Water ml
Lemon Syrup ml
syrup q.s. ad to ml
Procedure:
Dissolve the codeine phosphate in the purified water
Add 500 ml of the syrup and mix
Add the other ingredients and sufficient syrup to produce 1000 ml

9. SYRUPS – Percolation
Percolation: purified water is passed slowly through a bed of sucrose
Percolator is plugged at the neck with cotton ball or glass wool with sucrose on top
Flow of percolate is regulated by a suitable stopper
Syrup devoid of particles of sucrose is ensured by recycling percolate
Method of choice for Syrup USP & Wild Cherry Syrup

10. SYRUPS – Percolation Percolation: Rx: Procedure: Sucrose 85 gm
Purified Water, q.s. ad to 100 ml
Procedure:
Place sucrose in a suitable percolator, the neck of which is nearly filled with packed glass wool or cotton, moistened with distilled water
Pour carefully a portion of distilled water over sucrose and regulate the outflow to a steady drip
Return the flow from the drip back over the sucrose untill all the sucrose has dissolved
Use sufficient amounts of distilled water to bring the volume to 100 ml

11. THE END

12. Preserving Syrups
Syrup, USP is protected from bacterial contamination by virtue of its high solute concentration. More dilute syrups are good media for microbial growth and require the addition of preservatives. Industrially formulated syrups often contain ingredients to improve solubility, stability, taste or appearance which also contribute to product preservation. It is necessary, from an economic standpoint, to consider the additive preservative effects of such ingredients as alcohol, glycerin, propylene glycol, and other dissolve solids. Syrup USP, having a specific gravity of and a concentration of 85% w/v is a 65% w/w solution. This 65% by weight is the minimum amount of sucrose which will preserve neutral syrup. If one wants to formulate a syrup containing less sucrose, the quantity of alcohol, or other preservatives, may be estimated by considering the USP Syrup equivalent and the free water equivalent. One may assume that free water is preserved by 18% alcohol.
To calculate the free water equivalent, the volume occupied by the sucrose, the volume preserved by the sucrose, and the volume occupied and/or preserved by other additives must be subtracted from the total volume of the preparation. In Syrup, USP 850 g sucrose occupies an apparent volume of 550 ml; so each gram of sucrose will occupy 550/850 or ml. If the 850 g sucrose preserves 450 ml of water, then each gram of sucrose will preserve 450/850 = 0.53 ml of water.
e.g. How much Alcohol USP is required to preserve 1L of syrup containing 500 g sucrose?
If other dissolved solids are present, their volume (often estimated) is subtracted from the free water volume. If glycerin is present, its volume preserves an equal volume of free water. If propylene glycol is present, it is considered equivalent to ethanol.