Chloroquine Hydrochloride Injection
C18H26ClN3·2HCl 392.79

1,4-Pentanediamine, N4-(7-chloro-4-quinolinyl)-N1,N1-diethyl-, dihydrochloride.
7-(Chloro-4-4-diethylamino)-1-methylbutylaminoquinoline dihydrochloride [3545-67-3].
» Chloroquine Hydrochloride Injection is a sterile solution of Chloroquine in Water for Injection prepared with the aid of Hydrochloric Acid. It contains, in each mL, not less than 47.5 mg and not more than 52.5 mg of C18H26ClN3·2HCl.
Packaging and storage— Preserve in single-dose containers, preferably of Type I glass.
USP Reference standards 11
USP Chloroquine Phosphate RS Click to View Structure
USP Endotoxin RS
A: The UV absorption spectrum of the solution employed for measurement of absorbance in the Assay exhibits maxima and minima at the same wavelengths as that of a similar solution of USP Chloroquine Phosphate RS, concomitantly measured. The ratio A343/A329 is between 1.00 and 1.15.
B: To 20 mL of a dilution of Injection with water, containing about 20 mg of chloroquine hydrochloride, add 5 mL of trinitrophenol TS: a yellow precipitate is formed. Filter, wash the precipitate with water until the last washing is colorless, and dry over silica gel: the precipitate melts between 205 and 210. [Caution—Picrates may explode.]
C: It responds to the tests for Chloride 191.
Bacterial endotoxins 85 It contains not more than 0.7 USP Endotoxin Unit per mg of chloroquine hydrochloride.
pH 791: between 5.5 and 6.5.
Other requirements— It meets the requirements under Injections 1.
Assay— Transfer an accurately measured volume of Injection, equivalent to about 150 mg of chloroquine hydrochloride, to a 1000-mL volumetric flask, and dilute with water to volume. Transfer 5.0 mL of this solution to a 100-mL volumetric flask, add 10 mL of dilute hydrochloric acid (1 in 100), and dilute with water to volume. Dissolve an accurately weighed quantity of USP Chloroquine Phosphate RS in dilute hydrochloric acid (1 in 1000), and dilute quantitatively and stepwise with dilute hydrochloric acid (1 in 1000) to obtain a Standard solution having a known concentration of about 10 µg per mL. Concomitantly determine the absorbances of both solutions at the wavelength of maximum absorbance at about 343 nm, with a suitable spectrophotometer, using water as the blank. Calculate the quantity, in mg, of C18H26ClN3·2HCl in the portion of Injection taken by the formula:
15.23C(AU / AS)
in which C is the concentration, in µg per mL, of USP Chloroquine Phosphate RS in the Standard solution; and AU and AS are the absorbances of the solution from the Injection and the Standard solution, respectively.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Behnam Davani, Ph.D., M.B.A.
Senior Scientific Liaison
(SM12010) Monographs - Small Molecules 1
Reference Standards RS Technical Services
85 Radhakrishna S Tirumalai, Ph.D.
Principal Scientific Liaison
(GCM2010) General Chapters - Microbiology
USP35–NF30 Page 2631