Compounding Hotline

Q: Have you seen a formulation for sodium bicarbonatemouthwash 500 mL? The prescriber did not specifyconcentration.

A: Sodium bicarbonate has been used as a stomachicand in carminative mixtures. The Indian NationalFormulary gave "Sodium Bicarbonate Compound Mixture" assodium bicarbonate 300 mg, chloroform spirit 0.6 mL, compoundcardamom tincture 1 mL, aromatic ammonia spirit 1mL, ginger syrup 2 mL, and fennel water qs ad 15 mL. (Note:chloroform is no longer permitted as an ingredient in productsfor human use in the United States.)

The British Pharmaceutical Codex and the British NationalFormulary 1974 gave "Paediatric [sic] Sodium BicarbonateMixture" (the latter volume placed "Paediatric" at the end ofthe title) as "Sodium bicarbonate 50 mg, ginger syrup 0.2 mL,concentrated dill water 0.1 mL, syrup 1.85 mL, double-strengthchloroform water 2.5 mL, water qs ad 5 mL. It shouldbe recently prepared." (See the chloroform comment above.)

It would seem prudent to contact the prescriber to discusshis or her intentions regarding the use of the product and thefinal concentration desired.

Q: I am trying to prepare a vaginal douche and need tomeasure 18 mg of menthol. My scale does not measuremilligrams—it measures only grams. I was thinking of using thealiquot method, but menthol is only slightly soluble in water.

A: Although alcohol (pharmaceutical alcohol is ethanol)generally is not used vaginally, the solubility of mentholin 200-proof ethanol is 1 part in <1 part solvent ("very soluble").A dilution aliquot compounded with alcohol could provide theneeded solubilized menthol. Allowed to stand in open air,ethanol will evaporate, and the menthol will remain.

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

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