Edition: BP 2025 (Ph. Eur. 11.6 update)<\/p>\n
Action and use<\/strong><\/p>\n Amino acid. Ph Eur<\/p>\n (2S)-2-Amino-3-methylbutanoic acid.<\/p>\n Product of fermentation or of protein hydrolysis.<\/p>\n Content<\/strong><\/p>\n 98.5 per cent to 101.0 per cent (dried substance).<\/p>\n White or almost white, crystalline powder or colourless crystals.<\/p>\n Soluble in water, very slightly soluble in ethanol (96 per cent).<\/p>\n First identification: A, B.<\/em><\/p>\n Second identification: A, C.<\/em><\/p>\n A. Specific optical rotation (see Tests).<\/p>\n B. Infrared absorption spectrophotometry (2.2.24).<\/p>\n Comparison\u00a0 valine CRS.<\/p>\n C. Thin-layer chromatography (2.2.27).<\/p>\n Test solution Dissolve 10 mg of the substance to be examined in a 10.3 g\/L solution of hydrochloric acid R and dilute to 50 mL with the same solution.<\/p>\n Reference solution Dissolve 10 mg of valine CRS in a 10.3 g\/L solution of hydrochloric acid R and dilute to 50 mL with the same solution.<\/p>\n Plate\u00a0 TLC silica gel plate R.<\/p>\n Mobile phase glacial acetic acid R, water R, butanol R (20:20:60 V\/V\/V) Application 5 \u00b5L.<\/p>\n Development\u00a0 Over 2\/3 of the plate.<\/p>\n Drying\u00a0 In air.<\/p>\n Detection\u00a0 Spray with ninhydrin solution R and heat at 105 \u00b0C for 15 min.<\/p>\n Results 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 the reference solution.<\/p>\n Dissolve 2.5 g in water R and dilute to 100 mL with the same solvent.<\/p>\n Solution S is clear (2.2.1) and not more intensely coloured than reference solution BY6 (2.2.2, Method II).<\/p>\n Specific optical rotation (2.2.7)<\/strong><\/p>\n + 26.5 to + 29.0 (dried substance).<\/p>\n Dissolve 2.00 g in hydrochloric acid R1 and dilute to 25.0 mL with the same acid.<\/p>\n Amino acid analysis (2.2.56). For analysis, use Method 1.<\/p>\n The concentrations of the test solution and the reference solutions may be adapted according to the sensitivity of the equipment used. The concentrations of all solutions are adjusted so that the system suitability requirements described in general chapter 2.2.46 are fulfilled, keeping the ratios of concentrations between all solutions as described.<\/p>\n Solution A\u00a0 dilute hydrochloric acid R1 or a sample preparation buffer suitable for the apparatus used.<\/p>\n Test solution\u00a0 Dissolve 30.0 mg of the substance to be examined in solution A and dilute to 50.0 mL with solution A.<\/p>\n Reference solution (a)\u00a0 Dilute 1.0 mL of the test solution to 100.0 mL with solution A. Dilute 2.0 mL of this solution to 10.0 mL with solution A.<\/p>\n Reference solution (b) Dissolve 30.0 mg of proline R in solution A and dilute to 100.0 mL with solution A. Dilute 1.0 mL of the solution to 250.0 mL with solution A.<\/p>\n Reference solution (c)\u00a0 Dilute 6.0 mL of ammonium standard solution (100 ppm NH4) R to 50.0 mL with solution A. Dilute 1.0 mL of this solution to 100.0 mL with solution A.<\/p>\n Reference solution (d) Dissolve 30 mg of isoleucine R (impurity B) and 30 mg of leucine R (impurity C) in solution A and dilute to 50.0 mL with solution A. Dilute 1.0 mL of the solution to 200.0 mL with solution A.<\/p>\n Reference solution (e) Dissolve 30.0 mg of isoleucine R (impurity B) in solution A and dilute to 100.0 mL with solution A. Dilute 1.0 mL of the solution to 250.0 mL with solution A.<\/p>\n Blank solution\u00a0 Solution A.<\/p>\n Inject suitable, equal amounts of the test, blank and reference solutions into the amino acid analyser. Run a program suitable for the determination of physiological amino acids.<\/p>\n System suitability\u00a0 Reference solution (d):<\/p>\n \u2014 resolution: minimum 1.5 between the peaks due to impurities B and C.<\/p>\n Calculation of percentage contents:<\/p>\n \u2014 for impurity B, use the concentration of impurity B in reference solution (e);<\/p>\n \u2014 for any ninhydrin-positive substance detected at 570 nm, use the concentration of valine in reference solution (a);<\/p>\n \u2014 for any ninhydrin-positive substance detected at 440 nm, use the concentration of proline in reference solution (b); if a peak is above the reporting threshold at both wavelengths, use the result obtained at 570 nm for quantification.<\/p>\n Limits:<\/p>\n \u2014 impurity B at 570 nm: maximum 0.4 per cent;<\/p>\n \u2014 any ninhydrin-positive substance: for each impurity, maximum 0.2 per cent;<\/p>\n \u2014 total: maximum 1.0 per cent;<\/p>\n \u2014 reporting threshold: 0.05 per cent.<\/p>\n The thresholds indicated under Related substances (Table 2034.-1) in the general monograph Substances for pharmaceutical use (2034) do not apply.<\/p>\n Chlorides (2.4.4)<\/strong><\/p>\n Maximum 200 ppm.<\/p>\n Dilute 10 mL of solution S to 15 mL with water R.<\/p>\n Sulfates (2.4.13)<\/strong><\/p>\n Maximum 300 ppm.<\/p>\n Dissolve 0.5 g in distilled water R and dilute to 15 mL with the same solvent.<\/p>\n Amino acid analysis (2.2.56) as described in the test for ninhydrin-positive substances with the following modifications.<\/p>\n Injection\u00a0 Test solution, reference solution (c) and blank solution.<\/p>\n Limit:<\/p>\n \u2014 ammonium at 570 nm: not more than the area of the corresponding peak in the chromatogram obtained with reference solution (c) (0.02 per cent), taking into account the peak due to ammonium in the chromatogram obtained with the blank solution.<\/p>\n Iron (2.4.9)<\/strong><\/p>\n Maximum 10 ppm.<\/p>\n In a separating funnel, dissolve 1.0 g in 10 mL of dilute hydrochloric acid R. Shake with 3 quantities, each of 10 mL, of methyl isobutyl ketone R1, shaking for 3 min each time. To the combined organic layers add 10 mL of water R and shake for 3 min. Use the aqueous layer.<\/p>\n Loss on drying (2.2.32)<\/strong><\/p>\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)<\/strong><\/p>\n Maximum 0.1 per cent, determined on 1.0 g.<\/p>\n Dissolve 0.100 g in 3 mL of anhydrous formic acid R. Add 30 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 11.71 mg of C5<\/sub>H11<\/sub>NO2<\/sub>.<\/p>\n Protected from light.<\/p>\n Specified impurities\u00a0 B.<\/em><\/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. 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.<\/em><\/p>\n A. (2S)-2-aminopropanoic acid (alanine),<\/p>\n B. (2S,3S)-2-amino-3-methylpentanoic acid (isoleucine),<\/p>\n C. (2S)-2-amino-4-methylpentanoic acid (leucine).<\/p>\n","protected":false},"excerpt":{"rendered":" Edition: BP 2025 (Ph. Eur. 11.6 update) Action and use Amino acid. Ph Eur DEFINITION (2S)-2-Amino-3-methylbutanoic acid. Product of fermentation or of protein hydrolysis. Content 98.5 per cent to 101.0 per cent (dried substance). CHARACTERS Appearance White or almost white, crystalline powder or colourless crystals. Solubility Soluble in water, very slightly soluble in ethanol (96…<\/p>\n","protected":false},"author":5,"featured_media":30946,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-30945","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\/30945","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=30945"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/30945\/revisions"}],"predecessor-version":[{"id":30962,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/30945\/revisions\/30962"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/30946"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=30945"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=30945"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=30945"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}DEFINITION<\/h2>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
Solubility<\/h3>\n
IDENTIFICATION<\/h2>\n
TESTS<\/h1>\n
Solution S<\/h3>\n
Appearance of solution<\/h3>\n
Ninhydrin-positive substances<\/h3>\n
Ammonium<\/h3>\n
ASSAY<\/h2>\n
STORAGE<\/h2>\n
IMPURITIES<\/h2>\n