Betaxolol 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

Betaxolol Tablets contain an amount of Betaxolol Hydrochloride equivalent to NLT 90.0% and NMT 110.0% of the labeled amount of betaxolol hydrochloride (C₁₈H₂₉NO₃ · 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

Procedure

Buffer: 3.4 g/L of monobasic potassium phosphate in water, adjusted with phosphoric acid to a pH of 3.0

Mobile phase: Acetonitrile, methanol, and Buffer (175:175:650)

Standard solution: 1 mg/mL of USP Betaxolol Hydrochloride RS in Mobile phase

Sample solution: Nominally 1 mg/mL of betaxolol hydrochloride prepared as follows. Powder NLT 30 Tablets, transfer a portion of the powder containing nominally 20 mg of betaxolol hydrochloride to a 20-mL volumetric flask, and add 15 mL of Mobile phase. Sonicate for 10 min, and centrifuge for 30 min. Use the clear supernatant.

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 222 nm. For Identification B, use a diode array detector in the range of 210–400 nm.

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

Flow rate: 1.5 mL/min

Injection volume: 10 µL

System suitability

Sample: Standard solution

Suitability requirements

Tailing factor: NMT 3.0

Relative standard deviation: NMT 1.0%

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of betaxolol hydrochloride (C₁₈H₂₉NO₃ · HCl) in the portion of Tablets taken:

Result = (rᵤ/rₛ) × (Cₛ/Cᵤ) × 100

rᵤ = peak response from the Sample solution

rₛ = peak response from the Standard solution

Cₛ = concentration of USP Betaxolol Hydrochloride RS in the Standard solution (mg/mL)

Cᵤ = nominal concentration of betaxolol hydrochloride in the Sample solution (mg/mL)

Acceptance criteria: 90.0%–110.0%

4 PERFORMANCE TESTS

Dissolution 〈711〉

Medium: 0.01 N hydrochloric acid; 500 mL

Apparatus 2: 50 rpm

Time: 30 min

Standard solution: USP Betaxolol Hydrochloride RS in Medium

Sample solution: Sample per Dissolution 〈711〉. Dilute with Medium to a concentration that is similar to that of the Standard solution.

Instrumental conditions

Mode: UV

Analytical wavelength: 274 nm

Cell path length: A 5-cm path length cell may be used for lower dosage levels.

Analysis

Samples: Standard solution and Sample solution

Determine the percentage of the labeled amount of betaxolol hydrochloride (C₁₈H₂₉NO₃ · HCl) dissolved:

(Aᵤ/Aₛ) × Cₛ × D × (V/L) × 100

Aᵤ = absorbance of the Sample solution

Aₛ = absorbance of the Standard solution

Cₛ = concentration of the Standard solution (mg/mL)

D = dilution factor for the Sample solution, if needed

V = volume of Medium, 500 mL

L = label claim (mg/Tablet)

Tolerances: NLT 80% (Q) of the labeled amount of betaxolol hydrochloride (C₁₈H₂₉NO₃ · HCl) is dissolved.

Uniformity of Dosage Units 〈905〉: Meet the requirements (CN 1-Aug-2023)

Procedure for content uniformity

Standard solution: 0.1 mg/mL of USP Betaxolol Hydrochloride RS in 0.1 N hydrochloric acid

Sample solution: Place 1 Tablet in a suitable volumetric flask to obtain a concentration of betaxolol hydrochloride, based on the label claim, of 0.1 mg/mL. Add an amount of 0.1 N hydrochloric acid equal to 70% of the volume of the flask. Shake by mechanical means until dissolved, dilute with 0.1 N hydrochloric acid to volume, and mix. Filter, and discard the first 20 mL of the filtrate.

Instrumental conditions

Mode: UV

Analytical wavelength: 274 nm

Cell path length: 1 cm

Blank: 0.1 N hydrochloric acid

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of the labeled amount of betaxolol hydrochloride (C₁₈H₂₉NO₃ · HCl) in the Tablet taken:

Result = (Aᵤ/Aₛ) × (Cₛ/Cᵤ) × 100

Aᵤ = absorbance of the Sample solution

Aₛ = absorbance of the Standard solution

Cₛ = concentration of USP Betaxolol Hydrochloride RS in the Standard solution (mg/mL)

Cᵤ = nominal concentration of betaxolol hydrochloride in the Sample solution (mg/mL)

5 IMPURITIES

Organic Impurities

Buffer, Mobile phase, Sample solution, and Chromatographic system: Proceed as directed in the Assay.

System suitability solution: 1 mg/mL of USP Betaxolol Hydrochloride RS and 30 µg/mL of USP Betaxolol Related Compound A RS in Mobile phase

Standard solution: 6 µg/mL of USP Betaxolol Hydrochloride RS in Mobile phase

System suitability

Samples: System suitability solution and Standard solution

[Note—The relative retention times for betaxolol related compound A and betaxolol are 0.9 and 1.0, respectively.]

Suitability requirements

Resolution: NLT 2.0 between betaxolol related compound A and betaxolol, System suitability solution

Relative standard deviation: NMT 5.0%, Standard solution

Analysis

Samples: Sample solution and Standard solution

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

Result = (rᵤ/rₛ) × (Cₛ/Cᵤ) × (1/F) × 100

rᵤ = peak response of each impurity from the Sample solution

rₛ = peak response from the Standard solution

Cₛ = concentration of USP Betaxolol Hydrochloride RS in the Standard solution (mg/mL)

Cᵤ = nominal concentration of betaxolol hydrochloride in the Sample solution (mg/mL)

F = relative response factor for each individual impurity (see Table 1)

Acceptance criteria: See Table 1.

¹ 1-[4-(2-Hydroxyethyl)phenoxy]-3-(isopropylamino)propan-2-ol.

² 1-(4-Ethylphenoxy)-3-(isopropylamino)propan-2-ol.

³ It is a process impurity and is listed for identification only. It is controlled in the drug substance, is not reported for the drug product, and should not be included in the total degradation products.

⁴ 4-[2-Cyclopropylmethoxy)ethyl]phenol.

⁵ 1-[4-(2-Butoxyethyl)phenoxy]-3-(isopropylamino)propan-2-ol.

⁶ 2-({[4-(2-Cyclopropylmethoxy)ethyl]phenoxy}methyl)oxirane.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight containers.

Labeling: Label the Tablets to state both the content of the betaxolol active moiety and the content of betaxolol hydrochloride used in formulating them.

USP Reference Standards 〈11〉

USP Betaxolol Hydrochloride RS

USP Betaxolol Related Compound A RS

1-(4-Ethylphenoxy)-3-(isopropylamino)propan-2-ol.

C₁₄H₂₃NO₂ 237.34