Loratadine Oral Solution

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

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

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1 DEFINITION

Loratadine Oral Solution contains NLT 94.0% and NMT 105.0% of the labeled amount of loratadine (C₂₂H₂₃ClN₂O₂).

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

Procedure

Buffer: 6.8 g/L of monobasic potassium phosphate in water. Adjust with phosphoric acid to a pH of 3.0 ± 0.1.

Mobile phase: Acetonitrile and Buffer (3:7)

Diluent: Acetonitrile and water (3:7)

Internal standard solution: 0.3 mg/mL of USP Butylparaben RS in Diluent

Standard stock solution: 1.0 mg/mL of USP Loratadine RS in acetonitrile

Standard solution: Transfer 5.0 mL of Internal standard solution, 5.0 mL of Standard stock solution, and 12 mL of water into a 50-mL volumetric flask. Dilute with Diluent to volume.

Sample solution: Transfer a portion of Oral Solution, nominally equivalent to 5 mg of loratadine, into a 50-mL volumetric flask. Pipet 5.0 mL of Internal standard solution into the flask, and dilute with Diluent to volume.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm. For Identi

cation B, use a diode array detector in the range of 200–400 nm.

Column: 3.9-mm × 30-cm; 10-μm packing L11

Column temperature: 20°–30°

Flow rate: 2 mL/min

Injection volume: 10 μL

System suitability

Sample: Standard solution

[Note—The relative retention times for butylparaben and loratadine are about 0.78 and 1.0, respectively.]

Suitability requirements

Resolution: NLT 1.9 between loratadine and butylparaben

Tailing factor: NMT 1.6 for the loratadine and butylparaben peaks

Relative standard deviation: NMT 2%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of loratadine (C₂₂H₂₃ClN₂O₂) in the portion of Oral Solution taken:

Result = (R_U/R_S) × (C_S/C_U) × 100

R_U = peak response ratio of loratadine to the internal standard from the Sample solution

R_S = peak response ratio of loratadine to the internal standard from the Standard solution

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

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

Acceptance criteria: 94.0%–105.0%

4 PERFORMANCE TESTS

Deliverable Volume 〈698〉: Meets the requirements

5 IMPURITIES

Organic Impurities

Mobile phase: 4.3 g/L of sodium dodecyl sulfate in a mixture of acetonitrile and water (1:1). Adjust with phosphoric acid to a pH of 2.6 ± 0.1.

Diluent: Mobile phase and water (2:1)

System suitability solution 1: 2 μg/mL of USP Loratadine RS in Diluent

System suitability solution 2: 0.2 μg/mL of USP Loratadine RS in Diluent from System suitability solution 1

System suitability solution 3: Transfer an amount of Oral Solution, equivalent to 20 mg of loratadine, into a screw-cap glass container. Add 1mL of 3% aqueous Hydrogen peroxide and mix. Cap and heat at 65° for 18–24 h. Allow to cool to room temperature and then dilute 5 mL of the resulting solution with Diluent to 25 mL.

Sample solution: Nominally 0.2 mg/mL of loratadine from a volume of Oral Solution in Diluent

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 254 nm

Column: 4.6-mm × 25-cm; 5-μm packing L7

Column temperature: 30°–40°

Flow rate: 2 mL/min

Injection volume: 50 μL

System suitability

Samples: System suitability solution 1, System suitability solution 2, and System suitability solution 3

[Note—See Table 1 for relative retention times.]

Suitability requirements

Resolution: NLT 3.0 between loratadine and 2-hydroxymethyl loratadine, System suitability solution 3

Tailing factor: 0.7–1.1, System suitability solution 1

Relative standard deviation: NMT 10%, System suitability solution 2

Analysis

Sample: Sample solution

Calculate the percentage of each individual impurity in the portion of Oral Solution taken:

Result = (r_U/r_T) × 100

r_U = peak response of each individual impurity in the Sample solution

r_T = sum of all the peak responses in the Sample solution, excluding excipient peaks

Acceptance criteria: See Table 1.

Table 1

^a Ethyl 4-[8-chloro-5,6-dihydro-4-(hydroxymethyl)-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene]-1-piperidinecarboxylate.

^b Ethyl 4-[8-chloro-5,6-dihydro-2-(hydroxymethyl)-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene]-1-piperidinecarboxylate.

6 SPECIFIC TESTS

Microbial Enumeration Tests 〈61〉 and Tests for Specified Microorganisms 〈62〉: The total aerobic microbial count is NMT 102 cfu/mL, and the total combined molds and yeasts count is NMT 5 × 101 cfu/mL. It meets the requirements for the absence of Salmonella species and Escherichia coli.

pH 〈791〉: 2.2–3.1

7 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers, and store between 2° and 25°.

USP Reference Standards 〈11〉

USP Butylparaben RS

USP Loratadine RS