Tetrahydrozoline Hydrochloride
236.741H-Imidazole, 4,5-dihydro-2-(1,2,3,4-tetrahydro-1-naphthalenyl)-, monohydrochloride.
2-(1,2,3,4-Tetrahydro-1-naphthyl)-2-imidazoline monohydrochloride
[522-48-5].» Tetrahydrozoline Hydrochloride contains not less than 98.0 percent and not more than 100.5 percent of C13H16N2·HCl, calculated on the dried basis.
Packaging and storage—
Preserve in tight containers.
USP Reference standards 
11
—
USP Tetrahydrozoline Hydrochloride RS.
11—
USP Tetrahydrozoline Hydrochloride RS.
Identification—
Solution:
250 µg per mL.
Medium:
water.
Absorptivities at 264 nm and 271 nm, calculated on the dried basis, do not differ by more than 4.0%.
C:
A solution (1 in 200) responds to the tests for Chloride 191.
191.
Loss on drying 731—
Dry it at 105
for 2 hours: it loses not more than 1.0% of its weight.
731—
Dry it at 105 for 2 hours: it loses not more than 1.0% of its weight.
Residue on ignition 281:
not more than 0.1%.
281:
not more than 0.1%.
Heavy metals 231—
Dissolve 0.40 g in 23 mL of water, and add 2 mL of 1 N acetic acid: the limit is 0.005%.
231—
Dissolve 0.40 g in 23 mL of water, and add 2 mL of 1 N acetic acid: the limit is 0.005%.
Ordinary impurities 466—
466—
Test solution:
methanol.
Standard solution:
methanol.
Eluant:
a mixture of methanol, glacial acetic acid, and water (8:1:1).
Visualization:
3, followed by overspraying with hydrogen peroxide TS. [note—Cover the thin-layer chromatographic plate with a glass plate to slow fading of the spots.]
Assay—
Transfer about 400 mg of Tetrahydrozoline Hydrochloride, accurately weighed, to a 250-mL beaker, and dissolve in 60 mL of glacial acetic acid, heating if necessary. Add 5 mL of acetic anhydride, 5 mL of mercuric acetate TS, and 3 drops of quinaldine red TS, and titrate with 0.1 N perchloric acid VS. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 23.67 mg of C13H16N2·HCl.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
| Monograph | Feiwen Mao, M.S.
Scientist 1-301-816-8320 |
(MDOOD05) Monograph Development-Ophthalmics Oncologics and Dermatologicals |
| Reference Standards | Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org |
USP32–NF27 Page 3702