{"id":15946,"date":"2025-10-18T14:47:35","date_gmt":"2025-10-18T07:47:35","guid":{"rendered":"https:\/\/nhathuocngocanh.com\/bp\/?p=15946"},"modified":"2025-10-18T15:00:58","modified_gmt":"2025-10-18T08:00:58","slug":"erythromycin-and-zinc-acetate-lotion","status":"publish","type":"post","link":"https:\/\/nhathuocngocanh.com\/bp\/erythromycin-and-zinc-acetate-lotion\/","title":{"rendered":"Erythromycin and Zinc Acetate Lotion"},"content":{"rendered":"

(Ph. Eur. 11.6 update)<\/p>\n

Erythromycin and Zinc Acetate Cutaneous Solution<\/p>\n

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

Macrolide antibacterial.<\/p>\n

DEFINITION<\/h2>\n
Erythromycin and Zinc Acetate Lotion is a cutaneous solution. It contains 4% w\/v of Erythromycin and 1.2% w\/v of Zinc Acetate in a suitable ethanolic vehicle. It is prepared by dissolving the dry ingredients in the requisite volume of the vehicle provided before use.<\/p>\n
The lotion complies with the requirements stated under Liquids for Cutaneous Application.<\/p>\n
The dry ingredients comply with the requirements for Powders for Lotions stated under Liquids for Cutaneous Application and with the following requirements.<\/p>\n
Content of erythromycins, calculated as the sum of erythromycin A (C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>), erythromycin B (C_{37<\/sub>H_{67<\/sub>NO_{12<\/sub>) and erythromycin C (C_{36<\/sub>H_{65<\/sub>NO_{13<\/sub>)<\/strong><\/p>\n}}}}}}}}}
95.0 to 110.0% of the stated amount of Erythromycin.<\/p>\n
Content of zinc acetate, C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O<\/strong><\/p>\n}}}}
95.0 to 105.0% of the stated amount.<\/p>\n
IDENTIFICATION<\/h2>\n
A. In the Assay for erythromycin, the retention time of the principal peak in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).<\/p>\n
B. Mix a quantity of the powder with sufficient water to produce a 5% w\/v solution and filter. Add 0.5 mL of a 0.25M solution of potassium hexacyanoferrate(II) to 5 mL of the resulting solution and mix; a white precipitate is produced. Add 5 mL of 4M hydrochloric acid; the precipitate does not dissolve.<\/p>\n
TESTS<\/h2>\n
Related substances<\/strong><\/p>\n
Carry out the method for liquid chromatography, Appendix III D, using the following solutions in solution A. Prepare the solutions immediately before use and protect from light.<\/p>\n
Solution A 40 volumes of a 1.15% w\/v solution of dipotassium hydrogen orthophosphate adjusted to pH 8.0 using dilute phosphoric acid and 60 volumes of methanol R1.<\/p>\n
(1) Dissolve a quantity of the powder in solution A and dilute to produce a solution containing 0.4% w\/v of Erythromycin.<\/p>\n
(2) Dilute 1 volume of solution (1) to 100 volumes.<\/p>\n
(3) 0.4% w\/v of erythromycin for system suitability EPCRS.<\/p>\n
(4) Dilute 1 volumes of solution (2) to 5 volumes.<\/p>\n
CHROMATOGRAPHIC CONDITIONS<\/h3>\n
(a) Use a stainless steel column (25 cm \u00d7 4.6 mm) packed with end-capped polar-embedded octadecylsilyl amorphous organosilica polymer (3.5 \u03bcm) (X-Terra RP18 is suitable).<\/p>\n
(b) Use gradient elution and the mobile phase described below.<\/p>\n
(c) Use a flow rate of 1.0 mL per minute.<\/p>\n
(d) Use a column temperature of 65\u00b0.<\/p>\n
(e) Use a detection wavelength of 210 nm.<\/p>\n
(f) Inject 100 \u03bcL of each solution.<\/p>\n
MOBILE PHASE<\/h3>\n
Mobile phase A 5 volumes of a 3.5% w\/v solution of dipotassium hydrogen orthophosphate previously adjusted to pH 7.0 using dilute phosphoric acid, 35 volumes of acetonitrile R1 and 60 volumes of water.<\/p>\n
Mobile phase B 5 volumes of a 3.5% w\/v solution of dipotassium hydrogen orthophosphate previously adjusted to pH 7.0 using dilute phosphoric acid, 50 volumes of acetonitrile R1 and 45 volumes of water.<\/p>\n\n\n\n\n\n\n\n\n
Time (Minutes)<\/td>\n Mobile phase A (% v\/v)<\/td>\n Mobile phase B (% v\/v)<\/td>\n Comment<\/td>\n<\/tr>\n
0-44<\/td>\n 100<\/td>\n 0<\/td>\n isocratic<\/td>\n<\/tr>\n
44-46<\/td>\n 100\u21920<\/td>\n 0\u2192100<\/td>\n linear gradient<\/td>\n<\/tr>\n
46-61<\/td>\n 0<\/td>\n 100<\/td>\n isocratic<\/td>\n<\/tr>\n
61-63<\/td>\n 0\u2192100<\/td>\n 100\u21920<\/td>\n linear gradient<\/td>\n<\/tr>\n
63-80<\/td>\n 100<\/td>\n 0<\/td>\n re-equilibration<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
When the chromatograms are recorded under the prescribed conditions, the relative retentions with reference to erythromycin A (retention time about 23 minutes) are: impurity H, about 0.3; impurity A, about 0.4; impurity B, about 0.5; erythromycin C, about 0.55; impurity M, about 0.58; impurity L, about 0.63; impurity C, about 0.9; impurity D, about 1.6; erythromycin B, about 1.75; impurity F, about 1.8 and impurity E, about 2.3.<\/p>\n
SYSTEM SUITABILITY<\/h3>\n
The test is not valid unless, in the chromatogram obtained with solution (3):<\/p>\n
the resolution between the peaks due to impurity B and erythromycin C is at least 1.2;<\/p>\n
the peak-to-valley ratio is at least 2.0, where Hp is the height above the baseline of the peak due to impurity C and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin A;<\/p>\n
the peak-to-valley ratio is at least 1.5, where Hp is the height above the baseline of the peak due to impurity F and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin B.<\/p>\n
LIMITS<\/h3>\n
Identify any peaks corresponding to impurities D, E, F and L in the chromatogram obtained with solution (1), using the chromatogram obtained with solution (3), and multiply the areas of these peaks by the corresponding correction factors: impurity D, 2.0; impurity E, 0.08; impurity F, 0.08; impurity L, 0.11.<\/p>\n
In the chromatogram obtained with solution (1):<\/p>\n
the area of any peak corresponding to impurity C is not greater than 3 times the area of the principal peak in the chromatogram obtained with solution (2) (3%);<\/p>\n
the area of any peak corresponding to impurity A or B is not greater than 2 times the area of the principal peak in the chromatogram obtained with solution (2) (2% of each);<\/p>\n
the area of any peak corresponding to impurity D, E, F or H is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1% of each);<\/p>\n
the area of any peak corresponding to impurity L is not greater than 0.4 times the area of the principal peak in the chromatogram obtained with solution (2) (0.4%);<\/p>\n
the area of any other secondary peak, other than the peaks due to erythromycin B and C is not greater than 0.4 times the area of the principal peak in the chromatogram obtained with solution (2) (0.4%);<\/p>\n
the sum of the areas of any secondary peaks, other than the peaks due to erythromycin B and C is not greater than 7 times the area of the principal peak in the chromatogram obtained with solution (2) (7%).<\/p>\n
Disregard any peak due to erythromycin B and erythromycin C and any peak with an area less than the area of the principal peak in the chromatogram obtained with solution (4) (0.2%).<\/p>\n
The content of each of erythromycin B and erythromycin C, as determined under Assay, is not more than 5%.<\/p>\n
ASSAY<\/h2>\n
For erythromycin<\/h3>\n
Carry out the method for liquid chromatography, Appendix III D, using the following solutions in solution A. Prepare the solutions immediately before use and protect from light.<\/p>\n
Solution A 40 volumes of a 1.15% w\/v solution of dipotassium hydrogen orthophosphate adjusted to pH 8.0 using dilute phosphoric acid and 60 volumes of methanol.<\/p>\n
(1) Dissolve a quantity of the powder containing 0.4 g of Erythromycin in 75 mL of solution A and shake. Dilute to 100 mL.<\/p>\n
(2) 0.4% w\/v of erythromycin BPCRS.<\/p>\n
(3) 0.4% w\/v of erythromycin for system suitability EPCRS.<\/p>\n
CHROMATOGRAPHIC CONDITIONS<\/h4>\n
The chromatographic conditions described under Related substances may be used.<\/p>\n
SYSTEM SUITABILITY<\/h4>\n
The test is not valid unless, in the chromatogram obtained with solution (3):<\/p>\n
the resolution between the peaks due to impurity B and erythromycin C is at least 1.2;<\/p>\n
the peak-to-valley ratio is at least 2.0, where Hp is the height above the baseline of the peak due to impurity C and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin A;<\/p>\n
the peak-to-valley ratio is at least 1.5, where Hp is the height above the baseline of the peak due to impurity F and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin B.<\/p>\n
DETERMINATION OF CONTENT<\/h4>\n
Calculate the percentage content of erythromycin A(C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>), erythromycin B (C_{37<\/sub>H_{67<\/sub>NO_{12<\/sub>) and erythromycin C (C_{36<\/sub>H_{65<\/sub>NO_{13<\/sub>) using the chromatograms obtained with solutions (1) and (2) and the declared contents of C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>, C_{37<\/sub>H_{67<\/sub>NO_{12 <\/sub>and C_{36<\/sub>H_{65<\/sub>NO_{13 <\/sub>respectively in erythromycin BPCRS.<\/p>\n}}}}}}}}}}}}}}}}}}
For zinc acetate<\/h3>\n
To a quantity of the powder containing 0.2 g of Zinc Acetate add 5 mL of dilute acetic acid. Carry out the complexometric titration of zinc, Appendix VIII D. Each mL of 0.1M disodium edetate VS is equivalent to 21.95 mg of C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O.<\/p>\n}}}}
For the following tests prepare the lotion as directed on the label. The lotion complies with the requirements stated under Liquids for Cutaneous Application and with the following requirements.<\/p>\n
Content of erythromycins, calculated as the sum of erythromycin A (C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>), erythromycin B (C_{37<\/sub>H_{67<\/sub>NO_{12<\/sub>) and erythromycin C (C_{36<\/sub>H_{65<\/sub>NO_{13<\/sub>)<\/strong><\/p>\n}}}}}}}}}
99.0 to 110.0% of the stated amount of Erythromycin.<\/p>\n
Content of zinc acetate, C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O<\/strong><\/p>\n}}}}
90.0 to 110.0% of the stated amount.<\/p>\n
IDENTIFICATION<\/h2>\n
A. In the Assay for erythromycin, the retention time of the principal peak in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).<\/p>\n
B. Evaporate a suitable volume of the lotion to dryness on a water bath, add 20 mL of water to the residue, mix, with shaking, and filter. Add 1 mL of a 0.25M solution of potassium hexacyanoferrate(II) to the resulting filtrate and mix; a white precipitate is produced. Add 10 mL of 4M hydrochloric acid; the precipitate does not dissolve.<\/p>\n
TESTS<\/h2>\n
Clarity and colour of solution<\/p>\n
The solution is clear, Appendix IV A, and colourless, Appendix IV B, Method I.<\/p>\n
ASSAY<\/h2>\n
For erythromycin<\/h3>\n
Carry out the Assay for erythromycin described in the requirements for the dry ingredients. For solution (1) use a volume of the lotion containing 80 mg of Erythromycin in place of the powder.<\/p>\n
For zinc acetate<\/h3>\n
To a volume of the lotion containing 0.2 g of Zinc Acetate add 5 mL of dilute acetic acid. Carry out the complexometric titration of zinc, Appendix VIII D. Each mL of 0.1M disodium edetate VS is equivalent to 21.95 mg of C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O.<\/p>\n}}}}
STORAGE<\/h2>\n
Erythromycin and Zinc Acetate Lotion should be stored at the temperature and used within the period stated on the label.<\/p>\n
IMPURITIES<\/h2>\n
The impurities limited by the requirements of this monograph include those listed under Erythromycin.<\/p>\n","protected":false},"excerpt":{"rendered":"
(Ph. Eur. 11.6 update) Erythromycin and Zinc Acetate Cutaneous Solution Action and use Macrolide antibacterial. DEFINITION Erythromycin and Zinc Acetate Lotion is a cutaneous solution. It contains 4% w\/v of Erythromycin and 1.2% w\/v of Zinc Acetate in a suitable ethanolic vehicle. It is prepared by dissolving the dry ingredients in the requisite volume of…<\/p>\n","protected":false},"author":5,"featured_media":15974,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[175],"tags":[],"class_list":["post-15946","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\/15946","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=15946"}],"version-history":[{"count":5,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/15946\/revisions"}],"predecessor-version":[{"id":15988,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/15946\/revisions\/15988"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/15974"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=15946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=15946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=15946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

Time (Minutes)<\/td>\n	Mobile phase A (% v\/v)<\/td>\n	Mobile phase B (% v\/v)<\/td>\n	Comment<\/td>\n<\/tr>\n
0-44<\/td>\n	100<\/td>\n	0<\/td>\n	isocratic<\/td>\n<\/tr>\n
44-46<\/td>\n	100\u21920<\/td>\n	0\u2192100<\/td>\n	linear gradient<\/td>\n<\/tr>\n
46-61<\/td>\n	0<\/td>\n	100<\/td>\n	isocratic<\/td>\n<\/tr>\n
61-63<\/td>\n	0\u2192100<\/td>\n	100\u21920<\/td>\n	linear gradient<\/td>\n<\/tr>\n
63-80<\/td>\n	100<\/td>\n	0<\/td>\n	re-equilibration<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n When the chromatograms are recorded under the prescribed conditions, the relative retentions with reference to erythromycin A (retention time about 23 minutes) are: impurity H, about 0.3; impurity A, about 0.4; impurity B, about 0.5; erythromycin C, about 0.55; impurity M, about 0.58; impurity L, about 0.63; impurity C, about 0.9; impurity D, about 1.6; erythromycin B, about 1.75; impurity F, about 1.8 and impurity E, about 2.3.<\/p>\n SYSTEM SUITABILITY<\/h3>\n The test is not valid unless, in the chromatogram obtained with solution (3):<\/p>\n the resolution between the peaks due to impurity B and erythromycin C is at least 1.2;<\/p>\n the peak-to-valley ratio is at least 2.0, where Hp is the height above the baseline of the peak due to impurity C and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin A;<\/p>\n the peak-to-valley ratio is at least 1.5, where Hp is the height above the baseline of the peak due to impurity F and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin B.<\/p>\n LIMITS<\/h3>\n Identify any peaks corresponding to impurities D, E, F and L in the chromatogram obtained with solution (1), using the chromatogram obtained with solution (3), and multiply the areas of these peaks by the corresponding correction factors: impurity D, 2.0; impurity E, 0.08; impurity F, 0.08; impurity L, 0.11.<\/p>\n In the chromatogram obtained with solution (1):<\/p>\n the area of any peak corresponding to impurity C is not greater than 3 times the area of the principal peak in the chromatogram obtained with solution (2) (3%);<\/p>\n the area of any peak corresponding to impurity A or B is not greater than 2 times the area of the principal peak in the chromatogram obtained with solution (2) (2% of each);<\/p>\n the area of any peak corresponding to impurity D, E, F or H is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1% of each);<\/p>\n the area of any peak corresponding to impurity L is not greater than 0.4 times the area of the principal peak in the chromatogram obtained with solution (2) (0.4%);<\/p>\n the area of any other secondary peak, other than the peaks due to erythromycin B and C is not greater than 0.4 times the area of the principal peak in the chromatogram obtained with solution (2) (0.4%);<\/p>\n the sum of the areas of any secondary peaks, other than the peaks due to erythromycin B and C is not greater than 7 times the area of the principal peak in the chromatogram obtained with solution (2) (7%).<\/p>\n Disregard any peak due to erythromycin B and erythromycin C and any peak with an area less than the area of the principal peak in the chromatogram obtained with solution (4) (0.2%).<\/p>\n The content of each of erythromycin B and erythromycin C, as determined under Assay, is not more than 5%.<\/p>\n ASSAY<\/h2>\n For erythromycin<\/h3>\n Carry out the method for liquid chromatography, Appendix III D, using the following solutions in solution A. Prepare the solutions immediately before use and protect from light.<\/p>\n Solution A 40 volumes of a 1.15% w\/v solution of dipotassium hydrogen orthophosphate adjusted to pH 8.0 using dilute phosphoric acid and 60 volumes of methanol.<\/p>\n (1) Dissolve a quantity of the powder containing 0.4 g of Erythromycin in 75 mL of solution A and shake. Dilute to 100 mL.<\/p>\n (2) 0.4% w\/v of erythromycin BPCRS.<\/p>\n (3) 0.4% w\/v of erythromycin for system suitability EPCRS.<\/p>\n CHROMATOGRAPHIC CONDITIONS<\/h4>\n The chromatographic conditions described under Related substances may be used.<\/p>\n SYSTEM SUITABILITY<\/h4>\n The test is not valid unless, in the chromatogram obtained with solution (3):<\/p>\n the resolution between the peaks due to impurity B and erythromycin C is at least 1.2;<\/p>\n the peak-to-valley ratio is at least 2.0, where Hp is the height above the baseline of the peak due to impurity C and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin A;<\/p>\n the peak-to-valley ratio is at least 1.5, where Hp is the height above the baseline of the peak due to impurity F and Hv is the height above the baseline of the lowest point of the curve separating this peak from the peak due to erythromycin B.<\/p>\n DETERMINATION OF CONTENT<\/h4>\n Calculate the percentage content of erythromycin A(C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>), erythromycin B (C_{37<\/sub>H_{67<\/sub>NO_{12<\/sub>) and erythromycin C (C_{36<\/sub>H_{65<\/sub>NO_{13<\/sub>) using the chromatograms obtained with solutions (1) and (2) and the declared contents of C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>, C_{37<\/sub>H_{67<\/sub>NO_{12 <\/sub>and C_{36<\/sub>H_{65<\/sub>NO_{13 <\/sub>respectively in erythromycin BPCRS.<\/p>\n}}}}}}}}}}}}}}}}}} For zinc acetate<\/h3>\n To a quantity of the powder containing 0.2 g of Zinc Acetate add 5 mL of dilute acetic acid. Carry out the complexometric titration of zinc, Appendix VIII D. Each mL of 0.1M disodium edetate VS is equivalent to 21.95 mg of C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O.<\/p>\n}}}} For the following tests prepare the lotion as directed on the label. The lotion complies with the requirements stated under Liquids for Cutaneous Application and with the following requirements.<\/p>\n Content of erythromycins, calculated as the sum of erythromycin A (C_{37<\/sub>H_{67<\/sub>NO_{13<\/sub>), erythromycin B (C_{37<\/sub>H_{67<\/sub>NO_{12<\/sub>) and erythromycin C (C_{36<\/sub>H_{65<\/sub>NO_{13<\/sub>)<\/strong><\/p>\n}}}}}}}}} 99.0 to 110.0% of the stated amount of Erythromycin.<\/p>\n Content of zinc acetate, C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O<\/strong><\/p>\n}}}} 90.0 to 110.0% of the stated amount.<\/p>\n IDENTIFICATION<\/h2>\n A. In the Assay for erythromycin, the retention time of the principal peak in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).<\/p>\n B. Evaporate a suitable volume of the lotion to dryness on a water bath, add 20 mL of water to the residue, mix, with shaking, and filter. Add 1 mL of a 0.25M solution of potassium hexacyanoferrate(II) to the resulting filtrate and mix; a white precipitate is produced. Add 10 mL of 4M hydrochloric acid; the precipitate does not dissolve.<\/p>\n TESTS<\/h2>\n Clarity and colour of solution<\/p>\n The solution is clear, Appendix IV A, and colourless, Appendix IV B, Method I.<\/p>\n ASSAY<\/h2>\n For erythromycin<\/h3>\n Carry out the Assay for erythromycin described in the requirements for the dry ingredients. For solution (1) use a volume of the lotion containing 80 mg of Erythromycin in place of the powder.<\/p>\n For zinc acetate<\/h3>\n To a volume of the lotion containing 0.2 g of Zinc Acetate add 5 mL of dilute acetic acid. Carry out the complexometric titration of zinc, Appendix VIII D. Each mL of 0.1M disodium edetate VS is equivalent to 21.95 mg of C_{4<\/sub>H_{6<\/sub>O_{4<\/sub>Zn,2H_{2<\/sub>O.<\/p>\n}}}} STORAGE<\/h2>\n Erythromycin and Zinc Acetate Lotion should be stored at the temperature and used within the period stated on the label.<\/p>\n IMPURITIES<\/h2>\n The impurities limited by the requirements of this monograph include those listed under Erythromycin.<\/p>\n","protected":false},"excerpt":{"rendered":" (Ph. Eur. 11.6 update) Erythromycin and Zinc Acetate Cutaneous Solution Action and use Macrolide antibacterial. DEFINITION Erythromycin and Zinc Acetate Lotion is a cutaneous solution. It contains 4% w\/v of Erythromycin and 1.2% w\/v of Zinc Acetate in a suitable ethanolic vehicle. It is prepared by dissolving the dry ingredients in the requisite volume of…<\/p>\n","protected":false},"author":5,"featured_media":15974,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[175],"tags":[],"class_list":["post-15946","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\/15946","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=15946"}],"version-history":[{"count":5,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/15946\/revisions"}],"predecessor-version":[{"id":15988,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/posts\/15946\/revisions\/15988"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media\/15974"}],"wp:attachment":[{"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/media?parent=15946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/categories?post=15946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nhathuocngocanh.com\/bp\/wp-json\/wp\/v2\/tags?post=15946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

ASSAY<\/h2>\n

CHROMATOGRAPHIC CONDITIONS<\/h4>\nThe chromatographic conditions described under Related substances may be used.<\/p>\n

TESTS<\/h2>\nClarity and colour of solution<\/p>\nThe solution is clear, Appendix IV A, and colourless, Appendix IV B, Method I.<\/p>\n

ASSAY<\/h2>\n

For erythromycin<\/h3>\nCarry out the Assay for erythromycin described in the requirements for the dry ingredients. For solution (1) use a volume of the lotion containing 80 mg of Erythromycin in place of the powder.<\/p>\n

For zinc acetate<\/h3>\nTo a volume of the lotion containing 0.2 g of Zinc Acetate add 5 mL of dilute acetic acid. Carry out the complexometric titration of zinc, Appendix VIII D. Each mL of 0.1M disodium edetate VS is equivalent to 21.95 mg of C4<\/sub>H6<\/sub>O4<\/sub>Zn,2H2<\/sub>O.<\/p>\n

STORAGE<\/h2>\nErythromycin and Zinc Acetate Lotion should be stored at the temperature and used within the period stated on the label.<\/p>\n

CHROMATOGRAPHIC CONDITIONS<\/h4>\n
The chromatographic conditions described under Related substances may be used.<\/p>\n

TESTS<\/h2>\n
Clarity and colour of solution<\/p>\n
The solution is clear, Appendix IV A, and colourless, Appendix IV B, Method I.<\/p>\n

For erythromycin<\/h3>\n
Carry out the Assay for erythromycin described in the requirements for the dry ingredients. For solution (1) use a volume of the lotion containing 80 mg of Erythromycin in place of the powder.<\/p>\n

STORAGE<\/h2>\n
Erythromycin and Zinc Acetate Lotion should be stored at the temperature and used within the period stated on the label.<\/p>\n