Protriptyline Hydrochloride Tablets

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

Protriptyline Hydrochloride Tablets contain NLT 90.0% and NMT 110.0% of the labeled amount of protriptyline hydrochloride (C₁₉H₂₁N . 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: Dissolve 11 g of monobasic sodium phosphate and 1.9 g of sodium 1-hexanesulfonate in 900 mL of water. Dilute with water to 1 L and adjust with phosphoric acid to a pH of 2.9.

Solution A: Acetonitrile and Buffer (17:83)

Solution B: Acetonitrile and Buffer (50:50)

Mobile phase: See Table 1.

Table 1

Diluent: Mix 200 mL of alcohol and 40 mL of 2.5 N hydrochloric acid, and dilute with water to 1000 mL.

Standard solution: 200 µg/mL of USP Protriptyline Hydrochloride RS in Diluent

Sample solution: Nominally 200 µg/mL of protriptyline hydrochloride prepared as follows. Transfer NLT 5 Tablets to an appropriate volumetric flask. Add Diluent to about 80% of the flask volume, sonicate, and swirl as necessary to dissolve. Dilute with Diluent to volume. Pass a portion of the solution through a suitable filter of 0.45-µm pore size and discard the first 8 mL of the filtrate.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 280 nm. For Identification B, use a diode array detector in the range of 200–400 nm.

Column: 4.6-mm × 15-cm; 5-µm packing L7

Column temperature: 30°

Flow rate: 1.5 mL/min

Injection volume: 20 µL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 2.5

Relative standard deviation: NMT 2.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of protriptyline hydrochloride (C₁₉H₂₁N . HCl) in the portion of Tablets 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 Protriptyline Hydrochloride RS in the Standard solution (µg/mL)

C_U = nominal concentration of protriptyline hydrochloride in the Sample solution (µg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

4.1 Dissolution 〈711〉

Medium: Water; 900 mL

Apparatus 1: 100 rpm

Time: 45 min

Standard solution: USP Protriptyline Hydrochloride RS in Medium

Sample solution: Pass a portion of the solution under test through a suitable filter. Dilute the filtrate with Medium, if necessary, to a concentration that is similar to that of the Standard solution.

Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV

Analytical wavelength: 290 nm

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of protriptyline hydrochloride (C₁₉H₂₁N . HCl) dissolved:

Result = (A_U/A_S) × C_S × D × V × (1/L) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

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

D = dilution factor for the Sample solution, if needed

V = volume of Medium, 900 mL

L = label claim (mg/Tablet)

Tolerances: NLT 75% (Q) of the labeled amount of protriptyline hydrochloride (C₁₉H₂₁N . HCl) is dissolved.

4.2 Uniformity of Dosage Units 〈905〉: Meet the requirements

5 IMPURITIES

5.1 Organic Impurities

Solution A, Solution B, Mobile phase, Diluent, Sample solution, and Chromatographic system: Proceed as directed in the Assay.

Standard solution: 0.2 µg/mL of USP Protriptyline Hydrochloride RS in Diluent

System suitability

Sample: Standard solution

Suitability requirements

Relative standard deviation: NMT 5.0%

Analysis

Samples: Sample solution and Standard solution

Calculate the percentage of each unspecified degradation product in the portion of Tablets taken:

Result = (r_U/r_S) × (C_S/C_U) × 100

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

r_S = peak response of protriptyline hydrochloride from the Standard solution

C_S = concentration of USP Protriptyline Hydrochloride RS in the Standard solution (µg/mL)

C_U = nominal concentration of protriptyline hydrochloride in the Sample solution (µg/mL)

Acceptance criteria: Disregard any impurity peaks less than 0.05%.

Any individual, unspecified degradation product: NMT 0.2%

Total degradation products: NMT 1.0%

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers. Store at controlled room temperature.

USP Reference Standards 〈11〉

USP Protriptyline Hydrochloride RS