{"id":28918,"date":"2025-11-10T09:29:27","date_gmt":"2025-11-10T02:29:27","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=28918"},"modified":"2025-11-10T09:29:27","modified_gmt":"2025-11-10T02:29:27","slug":"protirelin","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/protirelin\/","title":{"rendered":"Protirelin"},"content":{"rendered":"

(Ph. Eur. monograph 1144)<\/p>\n

C_{16<\/sub>H_{22<\/sub>N_{6<\/sub>O_{4<\/sub>\u00a0 \u00a0 \u00a0 \u00a0 362.4\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a024305-27-9<\/p>\n}}}}

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

Thyrotrophin-releasing hormone.<\/p>\n

DEFINITION<\/h2>\n
5-Oxo-L-prolyl-L-histidyl-L-prolinamide.<\/p>\n
Synthetic tripeptide with the same sequence of amino acids as the natural hypothalamic neurohormone, which stimulates the release and synthesis of thyrotropin.<\/p>\n
Content<\/h3>\n
97.0 per cent to 102.0 per cent (anhydrous and acetic acid-free substance).<\/p>\n
CHARACTERS<\/h2>\n
Appearance<\/h3>\n
White or yellowish-white powder, hygroscopic.<\/p>\n
Solubility<\/h3>\n
Very soluble in water, freely soluble in methanol.<\/p>\n
IDENTIFICATION<\/h2>\n
A. Infrared absorption spectrophotometry (2.2.24).<\/p>\n
Comparison: protirelin CRS.<\/p>\n
B. Examine the chromatograms obtained in the assay.<\/p>\n
Results: The principal peak in the chromatogram obtained with the test solution is similar in retention time and size to the principal peak in the chromatogram obtained with the reference solution.<\/p>\n
TESTS<\/h2>\n
Appearance of solution<\/h3>\n
A 10 g\/L solution is clear (2.2.1) and not more intensely coloured than reference solution Y5 (2.2.2, Method II).<\/p>\n
Specific optical rotation (2.2.7)<\/h4>\n
-62 to -70 (anhydrous and acetic acid-free substance).<\/p>\n
Dissolve 10 mg in 1.0 mL of water R.<\/p>\n
Related substances<\/h3>\n
Liquid chromatography (2.2.29).<\/p>\n
Test solution: Dissolve 5.0 mg of the substance to be examined in mobile phase A and dilute to 5.0 mL with mobile phase A.<\/p>\n
Reference solution (a): Dissolve the contents of a vial of D-His-protirelin CRS in an appropriate volume of mobile phase A to obtain a concentration of 1 mg\/mL. Mix equal volumes of this solution and the test solution.<\/p>\n
Reference solution (b): Dilute 0.2 mL of the test solution to 10.0 mL with mobile phase A.<\/p>\n
Column:<\/p>\n
\u2014 size: l = 0.25 m, \u00d8 = 4.0 mm,<\/p>\n
\u2014 stationary phase: spherical octadecylsilyl silica gel for chromatography R (5 \u03bcm) with a pore size of 12 nm.<\/p>\n
Mobile phase:<\/p>\n
\u2014 mobile phase A: a mixture of 100 mL of acetonitrile for chromatography R, 1900 mL of water R and 2.0 g of sodium octanesulfonate R, containing 2.5 mL\/L of tetraethylammonium hydroxide solution R; adjust to pH 3.5 with phosphoric acid R,<\/p>\n
\u2014 mobile phase B: a mixture of 300 mL of acetonitrile for chromatography R, 1700 mL of water R and 2.0 g of sodium octanesulfonate R, containing 2.5 mL\/L of tetraethylammonium hydroxide solution R; adjust to pH 3.5 with phosphoric acid R,<\/p>\n\n\n\n\n\n\n
Time<\/strong>
\n(min)<\/strong><\/td>\n Mobile phase A<\/strong>
\n(per cent V\/V)<\/strong><\/td>\n Mobile phase B<\/strong>
\n(per cent V\/V)<\/strong><\/td>\n<\/tr>\n
0 – 30<\/td>\n 74 \u2192 41<\/td>\n 26 \u2192 59<\/td>\n<\/tr>\n
30 – 35<\/td>\n 41 \u2192 74<\/td>\n 59 \u2192 26<\/td>\n<\/tr>\n
35 – 50<\/td>\n 74<\/td>\n 26<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Flow rate: 1 mL\/min.<\/p>\n
Detection: Spectrophotometer at 210 nm.<\/p>\n
Injection: 10 \u03bcL.<\/p>\n
Relative retention: With reference to protirelin (retention time = about 18 min): impurity C = about 0.2; impurity D = about 0.68; impurity A = about 0.91; impurity B = about 0.95; impurity E = about 1.08.<\/p>\n
System suitability: Reference solution (a):<\/p>\n
\u2014 resolution: minimum 2.5 between the peaks due to impurity A and protirelin,<\/p>\n
\u2014 symmetry factor: 0.9 to 1.2 for the peak due to protirelin.<\/p>\n
Limits:<\/p>\n
\u2014 any impurity: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (2 per cent),<\/p>\n
\u2014 total: not more than 1.5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (3 per cent),<\/p>\n
\u2014 disregard limit: 0.05 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.1 per cent).<\/p>\n
Acetic acid (2.5.34)<\/h4>\n
Maximum 2.0 per cent.<\/p>\n
Test solution: Dissolve 40.0 mg of the substance to be examined in a mixture of 5 volumes of mobile phase B and 95 volumes of mobile phase A and dilute to 10.0 mL with the same mixture of solvents.<\/p>\n
Water (2.5.12)<\/h4>\n
Maximum 7.0 per cent, determined on 0.200 g.<\/p>\n
Bacterial endotoxins (2.6.14)<\/h4>\n
Less than 0.7 IU\/mg, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins.<\/p>\n
ASSAY<\/h2>\n
Liquid chromatography (2.2.29) as described in the test for related substances with the following modification.<\/p>\n
Reference solution: Dissolve the contents of a vial of protirelin CRS in an appropriate volume of mobile phase A to obtain a concentration of 1.0 mg\/mL.
\nCalculate the content of protirelin (C_{16<\/sub>H_{22<\/sub>N_{6<\/sub>O_{4<\/sub>) using the peak areas of the chromatograms obtained with the test solution and the reference solution and the declared content of C_{16<\/sub>H_{22<\/sub>N_{6<\/sub>O_{4<\/sub> in protirelin CRS.<\/p>\n}}}}}}}}
STORAGE<\/h2>\n
In an airtight container, protected from light at a temperature of 2 \u00b0C to 8 \u00b0C. If the substance is sterile, store in a sterile, airtight, tamper-evident container.<\/p>\n
LABELLING<\/h2>\n
The label states the mass of peptide in the container.<\/p>\n
IMPURITIES<\/h2>\n
Specified impurities A, B, C, D, E.<\/p>\n
$\"Protirelin\"$ <\/p>\n
A. 5-oxo-L-prolyl-D-histidyl-L-prolinamide,<\/p>\n
$\"Protirelin\"$ <\/p>\n
B. 5-oxo-D-prolyl-L-histidyl-L-prolinamide,<\/p>\n
$\"Protirelin\"$ <\/p>\n
C. 5-oxo-L-prolyl-L-histidine,<\/p>\n
$\"Protirelin\"$ <\/p>\n
D. 5-oxo-L-prolyl-L-histidyl-L-proline,<\/p>\n
$\"Protirelin\"$ <\/p>\n
E. (3S,8aS)-3-(1H-imidazol-4-ylmethyl)hexahydropyrrolo[1,2-a]pyrazine-1,4-dione (cyclo(-L-histidyl-L-prolyl-)).<\/p>\n","protected":false},"excerpt":{"rendered":"
(Ph. Eur. monograph 1144) C16H22N6O4\u00a0 \u00a0 \u00a0 \u00a0 362.4\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a024305-27-9 Action and use Thyrotrophin-releasing hormone. DEFINITION 5-Oxo-L-prolyl-L-histidyl-L-prolinamide. Synthetic tripeptide with the same sequence of amino acids as the natural hypothalamic neurohormone, which stimulates the release and synthesis of thyrotropin. Content 97.0 per cent to 102.0 per cent (anhydrous and acetic acid-free…<\/p>\n","protected":false},"author":2,"featured_media":28956,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-28918","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\/28918","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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=28918"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28918\/revisions"}],"predecessor-version":[{"id":28959,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28918\/revisions\/28959"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/28956"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=28918"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=28918"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=28918"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Time<\/strong> \n(min)<\/strong><\/td>\n	Mobile phase A<\/strong> \n(per cent V\/V)<\/strong><\/td>\n	Mobile phase B<\/strong> \n(per cent V\/V)<\/strong><\/td>\n<\/tr>\n
0 – 30<\/td>\n	74 \u2192 41<\/td>\n	26 \u2192 59<\/td>\n<\/tr>\n
30 – 35<\/td>\n	41 \u2192 74<\/td>\n	59 \u2192 26<\/td>\n<\/tr>\n
35 – 50<\/td>\n	74<\/td>\n	26<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Flow rate: 1 mL\/min.<\/p>\n Detection: Spectrophotometer at 210 nm.<\/p>\n Injection: 10 \u03bcL.<\/p>\n Relative retention: With reference to protirelin (retention time = about 18 min): impurity C = about 0.2; impurity D = about 0.68; impurity A = about 0.91; impurity B = about 0.95; impurity E = about 1.08.<\/p>\n System suitability: Reference solution (a):<\/p>\n \u2014 resolution: minimum 2.5 between the peaks due to impurity A and protirelin,<\/p>\n \u2014 symmetry factor: 0.9 to 1.2 for the peak due to protirelin.<\/p>\n Limits:<\/p>\n \u2014 any impurity: for each impurity, not more than the area of the principal peak in the chromatogram obtained with reference solution (b) (2 per cent),<\/p>\n \u2014 total: not more than 1.5 times the area of the principal peak in the chromatogram obtained with reference solution (b) (3 per cent),<\/p>\n \u2014 disregard limit: 0.05 times the area of the principal peak in the chromatogram obtained with reference solution (b) (0.1 per cent).<\/p>\n Acetic acid (2.5.34)<\/h4>\n Maximum 2.0 per cent.<\/p>\n Test solution: Dissolve 40.0 mg of the substance to be examined in a mixture of 5 volumes of mobile phase B and 95 volumes of mobile phase A and dilute to 10.0 mL with the same mixture of solvents.<\/p>\n Water (2.5.12)<\/h4>\n Maximum 7.0 per cent, determined on 0.200 g.<\/p>\n Bacterial endotoxins (2.6.14)<\/h4>\n Less than 0.7 IU\/mg, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins.<\/p>\n ASSAY<\/h2>\n Liquid chromatography (2.2.29) as described in the test for related substances with the following modification.<\/p>\n Reference solution: Dissolve the contents of a vial of protirelin CRS in an appropriate volume of mobile phase A to obtain a concentration of 1.0 mg\/mL. \nCalculate the content of protirelin (C_{16<\/sub>H_{22<\/sub>N_{6<\/sub>O_{4<\/sub>) using the peak areas of the chromatograms obtained with the test solution and the reference solution and the declared content of C_{16<\/sub>H_{22<\/sub>N_{6<\/sub>O_{4<\/sub> in protirelin CRS.<\/p>\n}}}}}}}} STORAGE<\/h2>\n In an airtight container, protected from light at a temperature of 2 \u00b0C to 8 \u00b0C. If the substance is sterile, store in a sterile, airtight, tamper-evident container.<\/p>\n LABELLING<\/h2>\n The label states the mass of peptide in the container.<\/p>\n IMPURITIES<\/h2>\n Specified impurities A, B, C, D, E.<\/p>\n $\"Protirelin\"$ <\/p>\n A. 5-oxo-L-prolyl-D-histidyl-L-prolinamide,<\/p>\n $\"Protirelin\"$ <\/p>\n B. 5-oxo-D-prolyl-L-histidyl-L-prolinamide,<\/p>\n $\"Protirelin\"$ <\/p>\n C. 5-oxo-L-prolyl-L-histidine,<\/p>\n $\"Protirelin\"$ <\/p>\n D. 5-oxo-L-prolyl-L-histidyl-L-proline,<\/p>\n $\"Protirelin\"$ <\/p>\n E. (3S,8aS)-3-(1H-imidazol-4-ylmethyl)hexahydropyrrolo[1,2-a]pyrazine-1,4-dione (cyclo(-L-histidyl-L-prolyl-)).<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. monograph 1144) C16H22N6O4\u00a0 \u00a0 \u00a0 \u00a0 362.4\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a024305-27-9 Action and use Thyrotrophin-releasing hormone. DEFINITION 5-Oxo-L-prolyl-L-histidyl-L-prolinamide. Synthetic tripeptide with the same sequence of amino acids as the natural hypothalamic neurohormone, which stimulates the release and synthesis of thyrotropin. Content 97.0 per cent to 102.0 per cent (anhydrous and acetic acid-free…<\/p>\n","protected":false},"author":2,"featured_media":28956,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[174],"tags":[],"class_list":["post-28918","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\/28918","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\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/comments?post=28918"}],"version-history":[{"count":2,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28918\/revisions"}],"predecessor-version":[{"id":28959,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/28918\/revisions\/28959"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/28956"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=28918"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=28918"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=28918"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Content<\/h3>\n97.0 per cent to 102.0 per cent (anhydrous and acetic acid-free substance).<\/p>\n

CHARACTERS<\/h2>\n

Appearance<\/h3>\nWhite or yellowish-white powder, hygroscopic.<\/p>\n

Solubility<\/h3>\nVery soluble in water, freely soluble in methanol.<\/p>\n

TESTS<\/h2>\n

Appearance of solution<\/h3>\nA 10 g\/L solution is clear (2.2.1) and not more intensely coloured than reference solution Y5 (2.2.2, Method II).<\/p>\n

Specific optical rotation (2.2.7)<\/h4>\n-62 to -70 (anhydrous and acetic acid-free substance).<\/p>\nDissolve 10 mg in 1.0 mL of water R.<\/p>\n

Acetic acid (2.5.34)<\/h4>\nMaximum 2.0 per cent.<\/p>\nTest solution: Dissolve 40.0 mg of the substance to be examined in a mixture of 5 volumes of mobile phase B and 95 volumes of mobile phase A and dilute to 10.0 mL with the same mixture of solvents.<\/p>\n

Water (2.5.12)<\/h4>\nMaximum 7.0 per cent, determined on 0.200 g.<\/p>\n

Bacterial endotoxins (2.6.14)<\/h4>\nLess than 0.7 IU\/mg, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins.<\/p>\n

STORAGE<\/h2>\nIn an airtight container, protected from light at a temperature of 2 \u00b0C to 8 \u00b0C. If the substance is sterile, store in a sterile, airtight, tamper-evident container.<\/p>\n

LABELLING<\/h2>\nThe label states the mass of peptide in the container.<\/p>\n

Content<\/h3>\n
97.0 per cent to 102.0 per cent (anhydrous and acetic acid-free substance).<\/p>\n

Appearance<\/h3>\n
White or yellowish-white powder, hygroscopic.<\/p>\n

Solubility<\/h3>\n
Very soluble in water, freely soluble in methanol.<\/p>\n

Appearance of solution<\/h3>\n
A 10 g\/L solution is clear (2.2.1) and not more intensely coloured than reference solution Y5 (2.2.2, Method II).<\/p>\n

Specific optical rotation (2.2.7)<\/h4>\n
-62 to -70 (anhydrous and acetic acid-free substance).<\/p>\n
Dissolve 10 mg in 1.0 mL of water R.<\/p>\n

Acetic acid (2.5.34)<\/h4>\n
Maximum 2.0 per cent.<\/p>\n
Test solution: Dissolve 40.0 mg of the substance to be examined in a mixture of 5 volumes of mobile phase B and 95 volumes of mobile phase A and dilute to 10.0 mL with the same mixture of solvents.<\/p>\n

Water (2.5.12)<\/h4>\n
Maximum 7.0 per cent, determined on 0.200 g.<\/p>\n

Bacterial endotoxins (2.6.14)<\/h4>\n
Less than 0.7 IU\/mg, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins.<\/p>\n

STORAGE<\/h2>\n
In an airtight container, protected from light at a temperature of 2 \u00b0C to 8 \u00b0C. If the substance is sterile, store in a sterile, airtight, tamper-evident container.<\/p>\n

LABELLING<\/h2>\n
The label states the mass of peptide in the container.<\/p>\n