Amyl Nitrite Inhalant

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

DOWNLOAD PDF HERE

Amyl Nitrite Inhalant

Amyl Nitrite Inhalant contains a mixture of the nitrite esters of 3-methyl-1-butanol and 2-methyl-1-butanol. It contains not less than 80.0 percent and not more than 105.0 percent of C₅H₁₁NO₂. It contains a suitable stabilizer.

[Caution—Amyl Nitrite Inhalant is very flammable. Do not use where it may be ignited.]

Packaging and storage— Preserve in tight, unit-dose glass containers, wrapped loosely in gauze or other suitable material, and store in a cool place, protected from light.

USP Reference standards 〈11〉—

USP Benzyl Benzoate RS

Specific gravity 〈841〉: between 0.870 and 0.880.

Content of total nitrites— Remove the gauze or other covering, place the glass container of Inhalant upright in a dry ice-acetone slurry, and cool for 10 minutes. Dry the container of Inhalant, place it in a pointed glass tube, and break the container with a glass rod. Proceed as directed for Total nitrites under Amyl Nitrite: not less than 95.0% is found.

Other requirements— It responds to the Identification tests and meets the requirements of the test for Acidity under Amyl Nitrite.

1 Assay

Solvent: carbon tetrachloride.

Internal standard— USP Benzyl Benzoate RS.

Procedure— Remove the gauze or other covering from 1 or more Inhalant ampuls containing a total of 300 to 400 µL of amyl nitrite. Weigh accurately the clean and dry intact glass ampul(s), and place the weighed specimen in a freezer for not less than 15 minutes. Transfer the chilled specimen to a glass-stoppered, 25-mL conical flask containing a solution of 4 to 5 mEq of Internal standard, accurately weighed, in 1 to 2 mL of carbon tetrachloride. Break the ampul(s) with a glass rod, and rinse any sample or glass fragments adhering to the glass rod with 1 mL of carbon tetrachloride into the main assay solution. Insert the stopper in the flask immediately, mix, and proceed as directed for Absolute Method of Quantitation under Nuclear Magnetic Resonance 〈761〉, beginning with “When dissolution has been completed.” With no spinning, or with the spinning adjusted so that the spinning side bands of neither the substance under assay nor the Internal standard interfere with the regions to be integrated, record as A₁ the average area of the Internal standard singlet appearing at about 5.3 ppm, representing the methylene protons of benzyl benzoate, and record as A₂ the average area of the multiplet with a band center at about 4.8 ppm, representing the alpha methylene protons of amyl nitrite, with reference to the tetramethylsilane singlet at 0 ppm. Calculate the quantity of C₅H₁₁NO₂ in the Inhalant taken, using 58.57 as the equivalent weight of amyl nitrite (EW₁) and 106.12 as that of benzyl benzoate (EW₂). Rinse the flask containing the assay preparation with three 5-mL portions of ether, decanting each rinsing carefully to avoid loss of glass fragments, and evaporate any remaining ether with the aid of a current of dry air. Transfer the dry glass fragments to a tared watch glass, weigh, and subtract the weight of the glass fragments from that of the intact ampul(s) to obtain the weight of the Inhalant taken.