Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n
General Notices<\/p>\n
Menthol in Aqueous Cream<\/p>\n
NOTE: This monograph has been developed to cover unlicensed formulations.<\/em><\/p>\n Levomenthol Cream contains Levomenthol in Aqueous Cream.<\/p>\n The cream complies with the requirements stated under Topical Semi-solid Preparations and with the following requirements. Where appropriate, the cream also complies with the requirements stated under Unlicensed Medicines.<\/p>\n Content of levomenthol, C10<\/sub>H20<\/sub>O<\/strong><\/p>\n 90.0 to 110.0% of the stated amount.<\/p>\n In the Assay, the chromatogram obtained with solution (2) shows a peak with the same retention time as the peak due to levomenthol in the chromatogram obtained with solution (3).<\/p>\n Carry out the method for gas chromatography, Appendix III B, using the following freshly prepared solutions.<\/p>\n (1) 0.1% w\/v of camphor (internal standard) in industrial methylated spirit (95%).<\/p>\n (2) Disperse a quantity of the well-mixed cream containing 50 mg of Levomenthol in 20 mL of industrial methylated spirit (95%) and mix with the aid of ultrasound for 15 minutes. Transfer the liquid contents to a 50 mL graduated flask, rinse the original flask with two 10-mL quantities of industrial methylated spirit (95%), transfer the washings to the graduated flask and add sufficient industrial methylated spirit (95%) to produce 50 mL; mix well and filter (Whatman No. 1 paper is suitable) discarding the first 5 mL of filtrate. Add 10 mL of solution (1) to 10 mL of the filtrate and add sufficient industrial methylated spirit (95%) to produce 25 mL; mix well.<\/p>\n (3) Mix 5 mL of a 0.2% w\/v solution of levomenthol BPCRS in industrial methylated spirit (95%) with 10 mL of solution (1) and dilute to 25 mL with industrial methylated spirit (95%).<\/p>\n (a) Use a fused silica column (10 m \u00d7 0.53 mm) bonded with a 0.25-\u03bcm layer of dimethylpolysiloxane.<\/p>\n (b) Use helium as the carrier gas.<\/p>\n (c) Use the gradient conditions described below.<\/p>\n (d) Use an inlet temperature of 250\u00b0.<\/p>\n (e) Use a flame ionisation detector at a temperature of 250\u00b0.<\/p>\n (f) Inject 1 \u03bcL of each solution.<\/p>\n When the chromatograms are recorded under the prescribed conditions the retention times are: levomenthol, about 2.1 minutes; camphor, about 2 minutes.<\/p>\n Calculate the content of C10<\/sub>H20<\/sub>O in the cream using the declared content of C10<\/sub>H20<\/sub>O in levomenthol BPCRS.<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) General Notices Menthol in Aqueous Cream NOTE: This monograph has been developed to cover unlicensed formulations. DEFINITION Levomenthol Cream contains Levomenthol in Aqueous Cream. The cream complies with the requirements stated under Topical Semi-solid Preparations and with the following requirements. Where appropriate, the cream also complies with the…<\/p>\n","protected":false},"author":5,"featured_media":20811,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[175],"tags":[],"class_list":["post-20807","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-formulated-preparations-specific-monographs"],"acf":[],"_links":{"self":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/20807","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=20807"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/20807\/revisions"}],"predecessor-version":[{"id":20833,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/20807\/revisions\/20833"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/20811"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=20807"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=20807"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=20807"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
IDENTIFICATION<\/h2>\n
ASSAY<\/h2>\n
CHROMATOGRAPHIC CONDITIONS<\/h3>\n
\n\n
\n Time (Minutes)<\/strong><\/td>\n Temperature<\/strong><\/td>\n Comment<\/strong><\/td>\n<\/tr>\n \n 0->1<\/td>\n 90\u00b0<\/td>\n isothermal<\/td>\n<\/tr>\n \n 1->5<\/td>\n 90\u00b0 -> 230\u00b0<\/td>\n linear gradient<\/td>\n<\/tr>\n \n 5->9<\/td>\n 230\u00b0<\/td>\n isothermal<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n DETERMINATION OF CONTENT<\/h3>\n