Azelastine Hydrochloride Ophthalmic Solution

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

1 DEFINITION

Azelastine Hydrochloride Ophthalmic Solution contains NLT 90.0% and NMT 110.0% of the labeled amount of azelastine hydrochloride (C₂₂H₂₄ClN₃O.HCl).

2 IDENTIFICATION

A. The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

B. The UV spectrum of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

3.1 PROCEDURE

Buffer 1: 2.88 g/L of octanesulfonic acid sodium salt and 0.91 g/L of monobasic potassium phosphate in water. Adjust with phosphoric acid to a pH of 3.0.

Buffer 2: 0.87 g/L of dibasic potassium phosphate in water. Adjust with phosphoric acid to a pH of 6.5.

Solution A: Acetonitrile and Buffer 1 (25:75)

Solution B: Acetonitrile

Mobile phase: See Table 1. Return to the original conditions, and re-equilibrate the system for NLT 5 min.

Table 1

Diluent: Acetonitrile and Buffer 2 (25:75)

System suitability solution: 2.5 µg/mL each of USP Azelastine Hydrochloride RS and USP Azelastine Related Compound F RS in Diluent

Standard solution: 0.08 mg/mL of USP Azelastine Hydrochloride RS in Diluent

Sample stock solution: Combine the contents of NLT 5 containers of Ophthalmic Solution.

Sample solution: Nominally 0.08 mg/mL of azelastine hydrochloride from the Sample stock solution in Diluent

Chromatographic system

(See Chromatography (621), System Suitability.)

Mode: LC

Detector: UV 210 nm

Column: 4.6-mm × 25-cm; 5-µm packing L10

Column temperature: 30°

Flow rate: 2 mL/min

Injection volume: 10 µL

System suitability

Samples: System suitability solution and Standard solution

[NOTE-See Table 2 for the relative retention times.]

Suitability requirements

Resolution: NLT 1.5 between azelastine and azelastine related compound F, System suitability solution

Tailing factor: NMT 1.5, Standard solution

Relative standard deviation: NMT 2.0%, Standard solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of azelastine hydrochloride (C₂₂H₂₄ClN₃O.HCl) in the portion of Ophthalmic Solution taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution 

C_S = concentration of USP Azelastine Hydrochloride RS in the Standard solution (mg/mL)

C_U = nominal concentration of azelastine hydrochloride in the Sample solution (mg/mL)

Acceptance criteria: 90.0%-110.0%

4 IMPURITIES

4.1 ORGANIC IMPURITIES

Mobile phase, Diluent, System suitability solution, Standard solution, Sample stock solution, and Chromatographic system: Proceed as directed in the Assay.

Sensitivity solution: 0.0005 mg/mL of USP Azelastine Hydrochloride RS in Diluent

Sample solution: Nominally 0.5 mg/mL of azelastine hydrochloride (use the Sample stock solution)

System suitability

Samples: System suitability solution, Standard solution, and Sensitivity solution

Suitability requirements

Resolution: NLT 1.5 between azelastine and azelastine related compound F, System suitability solution. [NOTE-If azelastine related compound F splits into two peaks, use the first peak for the determination of Resolution.]

Relative standard deviation: NMT 2.0%, Standard solution

Signal-to-noise ratio: NLT 10, Sensitivity solution

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of each degradation product in the portion of Ophthalmic Solution taken:

Result = (r_U/r_S) × (C_S/C_U) × (1/F) x 100

r_U = peak response of each degradation product from the Sample solution

r_S = peak response from the Standard solution 

C_S = concentration of USP Azelastine Hydrochloride RS in the Standard solution (mg/mL)

C_U = nominal concentration of azelastine hydrochloride in the Sample solution (mg/mL)

F = relative response factor (see Table 2)

Acceptance criteria: See Table 2.

Table 2

^a Process impurity included in the table for identification only. Process impurities are controlled in the drug substance and are not to be reported or included in the total degradation products.

^b N'-(1-Methylazepan-4-yl)benzohydrazide hydrochloride; also known as 1-Benzoyl-2-[(4RS)-1-methylhexahydro-1H-azepin-4-yl]diazane.

^c 2-[2-(4-Chlorophenyl)acetyl]benzoic acid.

^d 4-(4-Chlorobenzyl)phthalazin-1(2H)-one.

^e If the peak splits into two, identify both the peaks and quantify together.

^f 3-(4-Chlorobenzylidene) isobenzofuran-1(3H)-one.

5 SPECIFIC TESTS

PH (791): 5.0-6.5

OSMOLALITY AND OSMOLARITY (785): 265-375 mOsmol/kg

STERILITY TESTS (71): Meets the requirements

OTHER REQUIREMENTS: It meets the requirements in Ophthalmic Products-Quality Tests (771).

6 ADDITIONAL REQUIREMENTS

PACKAGING AND STORAGE: Preserve in tight containers at controlled room temperature.

USP REFERENCE STANDARDS (11).

USP Azelastine Hydrochloride RS

USP Azelastine Related Compound F. RS

4-[4-(4-Chlorobenzyl)-1-oxophthalazin-2(1H)-yl]-1-methylazepane 1-oxide.

C₂₂H₂₄CIN₃O₂  397.90 (USP 1-Aug-2019)