COMPOUNDINGHOTLINE

Q Do you have a recipe to make a metronidazole suspension using Cherry Simple Syrup and Ora-Sweet SF? I need to make it using this prescription: Dose: 20 mg/mL of metronidazole. Instructions: 5 mL twice a day. Total: 300 mL.

A Metronidazole suspension in a base of OraPlus 50%, OraSweet qs ad 100% is reported in the literature. Also reported is a suspension of metronidazole in cherry syrup. This syrup does not suspend insoluble drugs such as metronidazole very readily, creating potential compliance and dosing difficulties.

When a suspending agent such as OraPlus or methylcellulose 1% (preserved) is used as 50% of the preparation, a more elegant preparation is dispensed. With bitter drugs such as metronidazole, patient compliance hinges on the taste. One solution (pardon the pun) is to combine the dose, when administered, with an equal volume of a commercial food-grade chocolate syrup. Another suggestion is the use of metronidazole benzoate, a salt of metronidazole with virtually no associated taste issues. A weight conversion to obtain the correct dose is necessary, because the benzoate moiety contributes a large percentage of the molecular weight. A suggested metronidazole benzoate suspension formulation follows:

Metronidazole 250-mg/5-mL Suspension Calculated to Make 60 mL

Metronidazole benzoate*: 4.80 g

Propylene glycol: To wet

1% methylcellulose gel: 30.00 mL

Flavored syrup qs ad: 60.00 mL

• Wet the metronidazole with propylene glycol to make a stiff paste.
• Levigate in the 1% methylcellulose gel with trituration.
• After the powder is evenly dispersed in the gel, add the flavored syrup, and mix well.
• Refrigerate. Shake well before using.

*Be sure to use the benzoate salt of metronidazole.

Metronidazole benzoate 400 mg = metronidazole 250 mg

Metronidazole benzoate 200 mg = metronidazole 125 mg

No claims are made as to the uses, safety, efficacy, or bioavailability of this product. The formula is for informational purposes only.

E-mail your compounding questions to compounding@pharmacytimes.com

Mr. Erickson is director of professional affairs at Gallipot Inc.