US Pharm. 2009;34(4):38-39.

Method of Preparation: Calculate the required quantity of each ingredient for the total amount to be prepared. Obtain the ondansetron hydrochloride as a powder or from the commercial tablets. Pulverize the drug to a fine powder. Add the Ora-Plus in portions to the powder to form a smooth paste. Geometrically, add the desired vehicle in portions to volume, mixing well after each addition. Package and label. 

Use: Ondansetron oral liquid is used for the treatment of chemotherapy-induced nausea and vomiting, radiation-induced nausea and vomiting, and postoperative nausea and vomiting.1 

Packaging: Package in tight, light-resistant containers.2 

Labeling: Keep out of the reach of children. Use only as directed. Shake well. Store in the refrigerator.3 

Stability: A beyond-use date of up to 42 days when stored in a refrigerator can be used for this preparation.2,3 Ora-Sweet, Ora-Sweet SF, Cherry Syrup, and Syrpalta all were included in the stability study as vehicles. 

Quality Control: Quality-control assessment can include weight/volume, pH, specific gravity, active drug assay, color, rheologic properties/pourability, physical observation, and physical stability (discoloration, foreign materials, gas formation, mold growth).4 

Discussion: Ondansetron hydrochloride (C18H19N3O.HCl. 2H2O, MW 365.86, Zofran) occurs as a white to off-white powder that is sparingly soluble in water and in alcohol.2 Ondansetron hydrochloride has a melting point of around 180°C.

Each 4-mg or 8-mg Zofran tablet for oral administration contains 4 mg or 8 mg of ondansetron (as ondansetron hydrochloride dihydrate), along with microcrystalline cellulose, pregelatinized starch, hypromellose, magnesium stearate, titanium dioxide, and tria cetin. The 8-mg tablets also contain yellow iron oxide.5 These tablet excipients should be compatible with the vehicles recommended.

Ora-Plus is an oral suspending vehicle that accepts dilution of up to 50% or more with water, flavoring agents, or syrups and still retains its suspending properties. It has a pH of approximately 4.2 and an osmolality of about 230 mOsm/kg. It is a thixotropic vehicle with a viscosity of approximately 1,000 cps at 25°C. Ora-Plus contains purified water, microcrystalline cellulose, sodium carboxy methylcellulose, xanthan gum, carrageenan, sodium phosphate, and citric acid as buffering agents, simethicone as an antifoaming agent, and potassium sorbate and methylparaben as preservatives.6

Ora-Sweet syrup vehicle is a flavoring vehicle for oral extemporaneous preparations. It is flavored with a citrus-berry flavor blend and contains glycerin and sorbitol to prevent "cap-lock," a problem associated with many syrups. It is buffered to a pH of approximately 4.2 and has an osmolality of about 3,240 mOsm/kg. Ora-Sweet contains purified water, sucrose, glycerin, sorbitol (5%), flavoring, sodium phosphate, and citric acid as buffering agents and potassium sorbate and methylparaben as preservatives.7

Ora-Sweet SF sugar-free syrup vehicle is a flavoring vehicle for oral extemporaneous preparations. It is a sugar-free, alcohol-free syrup flavored with a citrus-berry flavor blend. It is buffered to a pH of approximately 4.2 and may be used alone or in combination with other vehicles. Ora-Sweet SF will tolerate a dilution to 50% with dissolved actives in water or suspending agents and still retain an acceptable taste. It has an osmolality of 2,150 mOsm/kg. It contains water, sodium saccharin, xanthan gum, glycerin, sorbitol, citric acid, and sodium citrate as buffers, methylparaben, propylparaben, and potassium sorbate as preservatives, and flavoring agents.8

Cherry Syrup consists of cherry juice (475 mL), sucrose (800 g), alcohol (20 mL), and purified water (to make 1,000 mL). It should be preserved in tight, light-resistant containers. Exposure to excessive heat should be prevented. The container should be labeled to state the Latin binomial name and, following the scientific name, the part of the plant source from which it was derived. Cherry Syrup contains from 1.0% to 2.0% alcohol. It is used as an oral vehicle.2

Syrpalta contains sucrose, purified water, flavor, glycerin, sodium benzoate, and benzalkonium chloride.9 


1. McEvoy GK, ed. AHFS Drug Information. Bethesda MD: American Society of Health-System Pharmacists; 2006:2890-2893.
2. US Pharmacopeial Convention, Inc. USP Pharmacists' Pharmacopeia. Rockville, MD: US Pharmacopeial Convention, Inc; 2005:362,408-413,699.
3. Williams CL, Sanders PL, Laizure SC, et al. Stability of ondansetron hydrochloride in syrups compounded from tablets. Am J Hosp Pharm. 1994;51:806-809.
4. Allen LV Jr. Standard operating procedure for performing physical quality assessment of oral and topical liquids. IJPC. 1999;3:146-147.
5. Physicians' Desk Reference. 61st ed. Montvale, NJ: Thomson PDR; 2007:1639-1644.
6. Ora-Plus (product information) Minneapolis, MN: Paddock Laboratories, Inc; 1992.
7. Ora-Sweet (product information). Minneapolis, MN: Paddock Laboratories, Inc; 2004.
8. Ora-Sweet SF (product information). Minneapolis, MN: Paddock Laboratories, Inc; 2004.
9. Syrpalta (product information). Texarkana, TX: Humco Holding Group, Inc; 1997.

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