{"id":28426,"date":"2025-11-08T14:47:06","date_gmt":"2025-11-08T07:47:06","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=28426"},"modified":"2025-11-08T14:47:06","modified_gmt":"2025-11-08T07:47:06","slug":"prilocaine","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/prilocaine\/","title":{"rendered":"Prilocaine"},"content":{"rendered":"

(Ph. Eur. monograph 1362)<\/em><\/p>\n

C13<\/sub>H20<\/sub>N2<\/sub>O 220.3 721-50-6<\/p>\n

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

Local anaesthetic.<\/p>\n

DEFINITION<\/h2>\n

(2RS)-N-(2-Methylphenyl)-2-(propylamino)propanamide.<\/p>\n

Content<\/h3>\n

99.0 per cent to 101.0 per cent (anhydrous substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\n

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

Solubility<\/h3>\n

Slightly soluble in water, very soluble in acetone and in ethanol (96 per cent).<\/p>\n

IDENTIFICATION<\/h2>\n

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

Preparation: Prepare a film between 2 plates of sodium chloride R by heating at 40-45 \u00b0C until the substance has melted.<\/p>\n

Comparison: prilocaine CRS.<\/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 2.50 g in 15 mL of dilute hydrochloric acid R and dilute to 50.0 mL with water R.<\/p>\n

Related substances<\/h3>\n

Liquid chromatography (2.2.29). Prepare the solutions immediately before use.<\/p>\n

Test solution: Dissolve 25 mg of the substance to be examined in the mobile phase and dilute to 10.0 mL with the mobile phase.<\/p>\n

Reference solution (a): Dissolve 2.5 mg of the substance to be examined and 3 mg of prilocaine impurity E CRS in the mobile phase and dilute to 100.0 mL with the mobile phase. Dilute 1.0 mL of the solution to 10.0 mL with the mobile phase.<\/p>\n

Reference solution (b): Dilute 1.0 mL of the test solution to 100.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 10.0 mL with the mobile phase.<\/p>\n

Reference solution (c): Dissolve 33.5 mg of prilocaine impurity B CRS in the mobile phase and dilute to 100.0 mL with the mobile phase. Dilute 1.0 mL of the solution to 100.0 mL with the mobile phase. Dilute 1.0 mL of this solution to 10.0 mL with the mobile phase.<\/p>\n

Reference solution (d): Dissolve 15 mg of prilocaine for peak identification CRS (containing impurity G) in the mobile phase and dilute to 5.0 mL with the mobile phase.<\/p>\n

Column:<\/p>\n

\u2014 size: l = 0.15 m, \u00d8 = 4.6 mm;<\/p>\n

\u2014 stationary phase: end-capped extra-dense bonded octadecylsilyl silica gel for chromatography R (5 \u03bcm).<\/p>\n

Mobile phase: Mix 26 volumes of acetonitrile for chromatography R and 74 volumes of a solution prepared as follows: dissolve 0.180 g of sodium dihydrogen phosphate monohydrate R and 2.89 g of disodium hydrogen phosphate dihydrate R in 1000 mL of water for chromatography R.<\/p>\n

Flow rate: 1.0 mL\/min.<\/p>\n

Detection: Spectrophotometer at 240 nm.<\/p>\n

Injection: 20 \u03bcL.<\/p>\n

Run time: Twice the retention time of prilocaine.<\/p>\n

Identification of impurities: Use the chromatogram obtained with reference solution (c) to identify the peak due to impurity B; use the chromatogram obtained with reference solution (a) to identify the peak due to impurity E; use the chromatogram obtained with reference solution (d) to identify the peak due to impurity G.<\/p>\n

Relative retention: With reference to prilocaine (retention time = about 25 min): impurity B = about 0.3; impurity G = about 0.8; impurity E = about 1.2.<\/p>\n

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

\u2014 resolution: minimum 3.0 between the peaks due to prilocaine and impurity E.<\/p>\n

Limits:<\/p>\n

\u2014 impurity B: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (c) (100 ppm);<\/p>\n

\u2014 impurity G: not more than 1.5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.15 per cent);<\/p>\n

\u2014 unspecified impurities: for each impurity, not more than 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 twice the area of the principal peak in the chromatogram obtained with reference solution (b) (0.2 per cent);<\/p>\n

\u2014 disregard limit: 0.5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.05 per cent).<\/p>\n

Water (2.5.12)<\/h3>\n

Maximum 0.5 per cent, determined on 1.000 g.<\/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 0.180 g in 50 mL of anhydrous acetic acid R. Titrate with 0.1 M perchloric acid, determining the end-point potentiometrically (2.2.20).<\/p>\n

1 mL of 0.1 M perchloric acid is equivalent to 22.03 mg of C13<\/sub>H20<\/sub>N2<\/sub>O.<\/p>\n

IMPURITIES<\/h2>\n

Specified impurities B, G.<\/p>\n

Other detectable impurities (the following substances would, if present at a sufficient level, be detected by one or other of the tests in the monograph. They are limited by the general acceptance criterion for other\/unspecified impurities and\/or by the general monograph Substances for pharmaceutical use (2034). It is therefore not necessary to identify these impurities for demonstration of compliance. See also 5.10. Control of impurities in substances for pharmaceutical use) A, C, D, E, F.<\/p>\n

\"Prilocaine\"<\/p>\n

A. (2RS)-2-chloro-N-(2-methylphenyl)propanamide,<\/p>\n

\"Prilocaine\"<\/p>\n

B. 2-methylbenzenamine (o-toluidine),<\/p>\n

\"Prilocaine\"<\/p>\n

C. (2RS)-2-(ethylamino)-N-(2-methylphenyl)propanamide,<\/p>\n

\"Prilocaine\"<\/p>\n

D. (2RS)-N-(3-methylphenyl)-2-(propylamino)propanamide,<\/p>\n

\"Prilocaine\"<\/p>\n

E. (2RS)-N-(4-methylphenyl)-2-(propylamino)propanamide,<\/p>\n

\"Prilocaine\"<\/p>\n

F. (2RS)-N-phenyl-2-(propylamino)propanamide,<\/p>\n

\"Prilocaine\"<\/p>\n

G. N-(2-methylphenyl)-2-(propylamino)acetamide.<\/p>\n","protected":false},"excerpt":{"rendered":"

(Ph. Eur. monograph 1362) C13H20N2O 220.3 721-50-6 Action and use Local anaesthetic. DEFINITION (2RS)-N-(2-Methylphenyl)-2-(propylamino)propanamide. Content 99.0 per cent to 101.0 per cent (anhydrous substance). CHARACTERS Appearance White or almost white, crystalline powder. Solubility Slightly soluble in water, very soluble in acetone and in ethanol (96 per cent). IDENTIFICATION Infrared absorption spectrophotometry (2.2.24). Preparation: Prepare a…<\/p>\n","protected":false},"author":4,"featured_media":28442,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-28426","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\/28426","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=28426"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28426\/revisions"}],"predecessor-version":[{"id":28452,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28426\/revisions\/28452"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/28442"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=28426"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=28426"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=28426"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}