﻿{"id":25799,"date":"2025-11-04T17:11:14","date_gmt":"2025-11-04T10:11:14","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=25799"},"modified":"2025-11-04T17:11:14","modified_gmt":"2025-11-04T10:11:14","slug":"natural-camphor","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/natural-camphor\/","title":{"rendered":"Natural Camphor"},"content":{"rendered":"<p>Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n<h2>DEFINITION<\/h2>\n<p>(1R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one.<\/p>\n<h2>CHARACTERS<\/h2>\n<h3>Appearance<\/h3>\n<p>White or almost white, crystalline powder or friable, crystalline masses. Highly volatile even at room temperature.<\/p>\n<h3>Solubility<\/h3>\n<p>Slightly soluble in water, very soluble in ethanol (96 per cent) and in light petroleum, freely soluble in fatty oils, very slightly soluble in glycerol.<\/p>\n<h2>IDENTIFICATION<\/h2>\n<p><em>First identification: A, C. <\/em><\/p>\n<p><em>Second identification: A, B, D.<\/em><\/p>\n<p>A. Specific optical rotation (see Tests).<\/p>\n<p>B. Melting point (2.2.14): 175 \u00b0C to 179 \u00b0C.<\/p>\n<p>C. Infrared absorption spectrophotometry (2.2.24).<\/p>\n<p><em>Comparison\u00a0 racemic camphor CRS.<\/em><\/p>\n<p>D. Dissolve 1.0 g in 30 mL of methanol R. Add 1.0 g of hydroxylamine hydrochloride R and 1.0 g of anhydrous sodium acetate R. Boil under a reflux condenser for 2h. Allow to cool and add 100 mL of water R. Filter, wash the precipitate obtained with 10 mL of water R and recrystallise from 10 mL of a mixture of 4 volumes of alcohol R and 6 volumes of water R. The crystals, dried in vacuo, melt (2.2.14) at 118 \u00b0C to 121 \u00b0C.<\/p>\n<h2>TESTS<\/h2>\n<p>Carry out the weighings and dissolution rapidly.<\/p>\n<h3>Solution S<\/h3>\n<p>Dissolve 2.50 g in 10 mL of alcohol R and dilute to 25.0 mL with the same solvent.<\/p>\n<h3>Appearance of solution<\/h3>\n<p>Solution S is clear (2.2.1) and colourless (2.2.2, Method II).<\/p>\n<h3>Acidity or alkalinity<\/h3>\n<p>To 10 mL of solution S add 0.1 mL of phenolphthalein solution R1. The solution is colourless. Not more than 0.2 mL of 0.1 M sodium hydroxide is required to change the colour of the indicator.<\/p>\n<p><strong>Specific optical rotation (2.2.7)<\/strong><\/p>\n<p>+ 41.0 to + 44.0, determined on solution S.<\/p>\n<h3>Related substances<\/h3>\n<p>Gas chromatography (2.2.28).<\/p>\n<p>Test solution\u00a0 Dissolve 2.50 g of the substance to be examined in heptane R and dilute to 25.0 mL with the same solvent.<\/p>\n<p>Reference solution (a) Dilute 1.0 mL of the test solution to 100.0 mL with heptane R. Reference solution (b) Dilute 10.0 mL of reference solution (a) to 20.0 mL with heptane R.<\/p>\n<p>Reference solution (c)\u00a0 Dissolve 0.50 g of borneol R in heptane R and dilute to 25.0 mL with the same solvent. Dilute 5.0 mL of the solution to 50.0 mL with heptane R.<\/p>\n<p>Reference solution (d) Dissolve 50 mg of linalol R and 50 mg of bornyl acetate R in heptane R and dilute to 100.0 mL with the same solvent.<\/p>\n<p>Column:<\/p>\n<p style=\"padding-left: 40px;\">\u2014 size: l = 30 m, \u00d8 = 0.25 mm,<\/p>\n<p style=\"padding-left: 40px;\">\u2014 stationary phase: macrogol 20 000 R (0.25 \u00b5m).<\/p>\n<p>Carrier gas helium for chromatography R. Split ratio 1:70.<\/p>\n<p>Flow rate\u00a0 45 cm\/s.<\/p>\n<p>Temperature:<\/p>\n<table style=\"border-collapse: collapse; width: 100%; height: 147px;\">\n<tbody>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\"><\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\"><strong>Time (min)<\/strong><\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\"><strong>Temperature (\u00b0C)<\/strong><\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\" rowspan=\"4\">Column<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">0 &#8211; 10<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">50<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">10 &#8211; 35<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">50 \u2192 100<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">35 &#8211; 45<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">100 \u2192 200<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">45 &#8211; 55<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">200<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\" colspan=\"2\">Injection port<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">220<\/td>\n<\/tr>\n<tr style=\"height: 21px;\">\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\" colspan=\"2\">Detector<\/td>\n<td style=\"width: 33.3333%; height: 21px; text-align: center;\">250<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Detection\u00a0 Flame ionisation.<\/p>\n<p>Injection\u00a0 1 \u00b5L.<\/p>\n<p>System suitability\u00a0 Reference solution (d).<\/p>\n<p style=\"padding-left: 40px;\">\u2014 resolution: minimum 3.0 between the peaks due to bornyl acetate and to linalol.<\/p>\n<p>Limits:<\/p>\n<p style=\"padding-left: 40px;\">\u2014 borneol: not more than the area of the principal peak in the chromatogram obtained with reference solution (c) (2.0 per cent),<\/p>\n<p style=\"padding-left: 40px;\">\u2014 any other impurity: not more than half of the area of the principal peak in the chromatogram obtained with reference solution (a) (0.5 per cent),<\/p>\n<p style=\"padding-left: 40px;\">\u2014 total of other impurities: not more than 4 times the area of the principal peak in the chromatogram obtained with reference solution (a) (4.0 per cent),<\/p>\n<p style=\"padding-left: 40px;\">\u2014 disregard limit: 0.1 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.05 per cent).<\/p>\n<h4>Halogens<\/h4>\n<p>Maximum 100 ppm.<\/p>\n<p>Dissolve 1.0 g in 10 mL of 2-propanol R in a distillation flask. Add 1.5 mL of dilute sodium hydroxide solution R and 50 mg of nickel-aluminium alloy R. Heat on a water-bath until the 2-propanol R has evaporated. Allow to cool and add 5 mL of water R. Mix and filter through a wet filter previously washed with water R until free from chlorides. Dilute the filtrate to 10.0 mL with water R. To 5.0 mL of the solution, add nitric acid R dropwise until the precipitate which forms is redissolved and dilute to 15 mL with water R. The solution complies with the limit test for chlorides (2.4.4).<\/p>\n<p>Residue on evaporation (2.8.9) Maximum 0.05 per cent.<\/p>\n<p>Evaporate 2.0 g on a water-bath and dry in an oven at 100-105 \u00b0C for 1 h. The residue weighs a maximum of 1 mg.<\/p>\n<h4>Water<\/h4>\n<p>Dissolve 1 g in 10 mL of light petroleum R. The solution is clear (2.2.1).<\/p>\n<h2>IMPURITIES<\/h2>\n<p>A. 2,6,6-trimethylbicyclo[3.1.1]hept-2-ene (\u03b1-pinene),<\/p>\n<p>B. 2,2-dimethyl-3-methylenebicyclo[2.2.1]heptane (camphene),<\/p>\n<p>C. 6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane (\u03b2-pinene),<\/p>\n<p>D. 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane (cineole),<\/p>\n<p>E. 1,3,3-trimethylbicyclo[2.2.1]heptan-2-one (fenchone),<\/p>\n<p>F. exo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol (fenchol),<\/p>\n<p>G. exo-2,3,3-trimethylbicyclo[2.2.1]heptan-2-ol (camphene hydrate),<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Edition: BP 2025 (Ph. Eur. 11.6 update) DEFINITION (1R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptan-2-one. CHARACTERS Appearance White or almost white, crystalline powder or friable, crystalline masses. Highly volatile even at room temperature. Solubility Slightly soluble in water, very soluble in ethanol (96 per cent) and in light petroleum, freely soluble in fatty oils, very slightly soluble in glycerol. IDENTIFICATION First&#8230;<\/p>\n","protected":false},"author":5,"featured_media":25800,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-25799","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\/25799","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\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=25799"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25799\/revisions"}],"predecessor-version":[{"id":25833,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/25799\/revisions\/25833"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/25800"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=25799"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=25799"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=25799"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}