{"id":4293,"date":"2025-09-27T10:39:29","date_gmt":"2025-09-27T03:39:29","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=4293"},"modified":"2025-10-02T16:32:56","modified_gmt":"2025-10-02T09:32:56","slug":"betaxolol-hydrochloride","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/betaxolol-hydrochloride\/","title":{"rendered":"Betaxolol Hydrochloride"},"content":{"rendered":"

(Ph. Eur. monograph 1072)<\/em><\/p>\n

C18<\/sub>H3<\/sub>0ClNO3<\/sub>\u00a0 \u00a0 343.9\u00a0 \u00a063659-19-8<\/p>\n

Action and use<\/strong><\/p>\n

Beta-adrenoceptor antagonist.<\/p>\n

Preparations<\/strong><\/p>\n

Betaxolol Eye Drops, Solution<\/p>\n

Betaxolol Eye Drops, Suspension<\/p>\n

DEFINITION<\/h2>\n

(2RS)-1-[4-[2-(Cyclopropylmethoxy)ethyl]phenoxy]-3-[(1-methylethyl)amino]propan-2-ol hydrochloride.<\/p>\n

Content<\/h3>\n

98.5 per cent to 101.5 per cent (dried substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

White or almost white, crystalline powder.<\/p>\n

Solubility<\/h3>\n

Very soluble in water, freely soluble in ethanol (96 per cent), soluble in methylene chloride.<\/p>\n

IDENTIFICATION<\/h2>\n

First identification: B, D.<\/p>\n

Second identification: A, C, D.<\/p>\n

A. Melting point (2.2.14): 113 \u00b0C to 117 \u00b0C.<\/p>\n

B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n

Comparison betaxolol hydrochloride CRS.<\/p>\n

C. Thin-layer chromatography (2.2.27).<\/p>\n

Test solution: Dissolve 10 mg of the substance to be examined in 1 mL of methanol R.<\/p>\n

Reference solution (a): Dissolve 20 mg of betaxolol hydrochloride CRS in 2 mL of methanol R.<\/p>\n

Reference solution (b): Dissolve 10 mg of oxprenolol hydrochloride CRS in 1 mL of reference solution (a).<\/p>\n

Plate: TLC octadecylsilyl silica gel F254 plate R.<\/p>\n

Mobile phase: perchloric acid R, methanol R, water R (0.5:50:50 V\/V\/V).<\/p>\n

Application: 2 \u03bcL.<\/p>\n

Development: Over a path of 10 cm.<\/p>\n

Drying: In air.<\/p>\n

System suitability: Reference solution (b):<\/p>\n

\u2014 the chromatogram shows 2 clearly separated spots.<\/p>\n

Detection A: Examine in ultraviolet light at 254 nm.<\/p>\n

Results A: The principal spot in the chromatogram obtained with the test solution is similar in position and size to the principal spot in the chromatogram obtained with reference solution (a).<\/p>\n

Detection B: Spray with a 50 g\/L solution of vanillin R in a mixture of 5 volumes of sulfuric acid R, 10 volumes of glacial acetic acid R and 85 volumes of methanol R, heat at 100-105 \u00b0C until the colour of the spots reaches maximum intensity (10-15 min), and examine in daylight.<\/p>\n

Results B: The principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with reference solution (a).<\/p>\n

D. It gives reaction (a) of chlorides (2.3.1).<\/p>\n

TESTS<\/h2>\n

Appearance of solution<\/h3>\n

The solution is clear (2.2.1) and colourless (2.2.2, Method II).<\/p>\n

Dissolve 0.5 g in water R and dilute to 25 mL with the same solvent.<\/p>\n

Acidity or alkalinity<\/h3>\n

Dissolve 0.20 g in carbon dioxide-free water R and dilute to 20 mL with the same solvent. Add 0.2 mL of methyl red solution R and 0.2 mL of 0.01 M hydrochloric acid. The solution is red. Add 0.4 mL of 0.01 M sodium hydroxide. The solution is yellow.<\/p>\n

Related substances: Liquid chromatography (2.2.29). Prepare reference solutions (c) and (d) immediately before use.<\/p>\n

Test solution: Dissolve 10 mg of the substance to be examined in the mobile phase and dilute to 5.0 mL with the mobile phase.<\/p>\n

Reference solution (a): Dissolve 8 mg of the substance to be examined and 4 mg of betaxolol impurity A CRS in 20.0 mL of the mobile phase.<\/p>\n

Reference solution (b): Dilute 1.0 mL of the test solution to 100.0 mL with the mobile phase.<\/p>\n

Reference solution (c): Dissolve 2 mg of betaxolol impurity C CRS in 50 mL of the mobile phase. Dilute 5 mL of the solution to 20 mL with the mobile phase.<\/p>\n

Reference solution (d): Dissolve 10 mg of betaxolol for peak identification CRS (containing impurities B, D and E) in 5 m of reference solution (c).<\/p>\n

Column:<\/p>\n

\u2014 size: l = 0.25 m, \u00d8 = 4 mm;<\/p>\n

\u2014 stationary phase: octylsilyl silica gel for chromatography R (5 \u03bcm).<\/p>\n

Mobile phase: Mix 175 mL of acetonitrile R and 175 mL of methanol R and dilute to 1 L with a 3.4 g\/L solution of potassium dihydrogen phosphate R, previously adjusted to pH 3.0 with phosphoric acid R.<\/p>\n

Flow rate: 1.5 mL\/min.<\/p>\n

Detection: Spectrophotometer at 273 nm.
\nInjection: 20 \u03bcL of the test solution and reference solutions (a), (b) and (d).<\/p>\n

Run time: 4.5 the retention time of betaxolol.<\/p>\n

Identification of impurities: Use the chromatogram obtained with reference solution (a) to identify the peak due to impurity A; use the chromatogram supplied with betaxolol for peak identification CRS and the chromatogram obtained with reference solution (d) to identify the peaks due to impurities B, C, D and E.<\/p>\n

Relative retention: With reference to betaxolol (retention time = about 8 min): impurity B = about 0.3; impurity A = about 0.8; impurity D = about 1.5; impurity E = about 2.2; impurity C = about 4.1.<\/p>\n

System suitability: Reference solution (a):<\/p>\n

\u2014 resolution: minimum 2.0 between the peaks due to impurity A and betaxolol.<\/p>\n

Limits:<\/p>\n

\u2014 impurities A, B, C, D, E: for each impurity, not more than 0.3 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.3 per cent);<\/p>\n

\u2014 unspecified impurities: for each impurity, not more than 0.1 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.10 per cent);<\/p>\n

\u2014 total: not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (1.0 per cent);<\/p>\n

\u2014 disregard limit: 0.05 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.05 per cent).<\/p>\n

Loss on drying (2.2.32)<\/h3>\n

Maximum 0.5 per cent, determined on 1.000 g by drying in an oven at 105 \u00b0C.<\/p>\n

Sulfated ash (2.4.14)<\/h3>\n

Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n

ASSAY<\/h2>\n

Dissolve 0.300 g in a mixture of 10.0 mL of 0.01 M hydrochloric acid and 50 mL of ethanol (96 per cent) R. Carry out a potentiometric titration (2.2.20), using 0.1 M sodium hydroxide. Read the volume added between the 2 points of inflexion.<\/p>\n

1 mL of 0.1 M sodium hydroxide is equivalent to 34.39 mg of C18H30ClNO3.<\/p>\n

STORAGE<\/h2>\n

Protected from light.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities A, B, C, D, E.<\/p>\n

\"Betaxolol<\/p>\n

A. (2RS)-1-(4-ethylphenoxy)-3-[(1-methylethyl)amino]propan-2-ol,<\/p>\n

\"Betaxolol<\/p>\n

B. (2RS)-1-[4-(2-hydroxyethyl)phenoxy]-3-[(1-methylethyl)amino]propan-2-ol,<\/p>\n

\"Betaxolol<\/p>\n

C. (2RS)-2-[[4-[2-(cyclopropylmethoxy)ethyl]phenoxy]methyl]oxirane,<\/p>\n

\"Betaxolol<\/p>\n

D. 4-[2-(cyclopropylmethoxy)ethyl]phenol,<\/p>\n

\"Betaxolol<\/p>\n

E. (2RS)-1-[4-(2-butoxyethyl)phenoxy]-3-[(1-methylethyl)amino]propan-2-ol.<\/p>\n","protected":false},"excerpt":{"rendered":"

(Ph. Eur. monograph 1072) C18H30ClNO3\u00a0 \u00a0 343.9\u00a0 \u00a063659-19-8 Action and use Beta-adrenoceptor antagonist. Preparations Betaxolol Eye Drops, Solution Betaxolol Eye Drops, Suspension DEFINITION (2RS)-1-[4-[2-(Cyclopropylmethoxy)ethyl]phenoxy]-3-[(1-methylethyl)amino]propan-2-ol hydrochloride. Content 98.5 per cent to 101.5 per cent (dried substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Very soluble in water, freely soluble in ethanol (96 per cent),…<\/p>\n","protected":false},"author":4,"featured_media":4630,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-4293","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-medicinal-substances"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/4293","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=4293"}],"version-history":[{"count":6,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/4293\/revisions"}],"predecessor-version":[{"id":8009,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/4293\/revisions\/8009"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/4630"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=4293"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=4293"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=4293"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}