- British Pharmacopoeia Volume III
- Formulated Preparations: Specific Monographs
Ergometrine and Oxytocin Injection |
Oxytocic.
Ergometrine and Oxytocin Injection is a sterile solution containing Ergometrine Maleate and either Oxytocin or Oxytocin Concentrated Solution in Water for Injections. The acidity of the solution is adjusted to pH 3.3 by the addition of maleic acid.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
90.0 to 110.0% of the stated amount.
90.0 to 110.0% of the stated amount.
A colourless solution.
A. In the test for Substances related to ergometrine, the principal spot in the chromatogram obtained with solution (1) corresponds to that in the chromatogram obtained with solution (2).
B. To a volume containing 0.1 mg of Ergometrine Maleate, add 0.5 mL of water and 2 mL of dimethylaminobenzaldehyde solution R6. After about 5 minutes a deep blue colour is produced.
C. In the Assay for oxytocin a peak in the chromatogram obtained with solution (2) corresponds to the peak due to oxytocin in the chromatogram obtained with solution (1).
pH, 2.9 to 3.5, Appendix V L.
Carry out in subdued light the method for thin-layer chromatography, Appendix III A, using silica gel G as the coating substance and a mixture of 75 volumes of chloroform, 25 volumes of methanol and 3 volumes of water as the mobile phase but allowing the solvent front to ascend 14 cm above the line of application. Apply separately to the plate 5 µL of each of the following solutions. For solution (1) add 10 mL of absolute ethanol to a volume of the injection containing 0.5 mg of Ergometrine Maleate and evaporate to dryness at a temperature not exceeding 30° at a pressure of 2 kPa; to the residue add 0.2 mL of a mixture of 1 volume of 13.5m ammonia and 9 volumes of ethanol (80%), mix, centrifuge and use the supernatant liquid. Solutions (2), (3), (4), (5) and (6) contain 0.250% w/v, 0.0250% w/v, 0.0125% w/v, 0.0050% w/v and 0.00250% w/v of ergometrine maleate BPCRS respectively in a mixture of 1 volume of 3.5m ammonia and 9 volumes of ethanol (80%). After removal of the plate, dry it in a current of cold air, spray with dimethylaminobenzaldehyde solution R7 and dry the plate at 105° for 2 minutes. Assess the intensities of any secondary spots in the chromatogram obtained with solution (1) by reference to the spots in the chromatograms obtained with solutions (3) to (6), making allowance for area in assessing the intensities of spots of different Rf values. The sum of the intensities so assessed does not exceed 10% of the intensity of the principal spot.
Carry out the method for liquid chromatography, Appendix III D, using the following solutions. Solution (1) contains 0.05% w/v of ergometrine maleate BPCRS. Solution (2) is the injection diluted, if necessary, to give a solution containing 0.05% w/v of Ergometrine Maleate.
The chromatographic procedure may be carried out using (a) a stainless steel column (10 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (Nucleosil C18 is suitable) and maintained at 40°, (b) a mixture of 92 volumes of a 0.2% v/v solution of orthophosphoric acid and 8 volumes of acetonitrile as the mobile phase with a flow rate of 1 mL per minute and (c) a detection wavelength of 320 nm.
Calculate the content of C19H23N3O2,C4H4O4 from the declared content of C19H23N3O2,C4H4O4 in ergometrine maleate BPCRS.
Carry out the method for liquid chromatography, Appendix III D, injecting 0.2 mL of each of the following solutions. Solution (1) contains 8 µg of oxytocin EPCRS per mL. Solution (2) is the injection diluted, if necessary, to give a solution containing about 8 µg of Oxytocin per mL.
The chromatographic procedure may be carried out using a stainless steel column (10 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 µm) (Nucleosil C18 is suitable) and maintained at 40°, (b) a mixture of 85 volumes of a 0.2% v/v solution of orthophosphoric acid and 15 volumes of acetonitrile as the mobile phase with a flow rate of 1 mL per minute and (c) a detection wavelength of 220 nm. If necessary adjust the content of acetonitrile in the mobile phase so that the retention time of oxytocin is about 14 minutes. Record the chromatogram for sufficient time to ensure elution of any preservatives.
The column efficiency, determined using the peak due to oxytocin in the chromatogram obtained with solution (1), should be not less than 50,000 theoretical plates per metre.
Calculate the content of C43H66N12O12S2 from the declared content of peptide in oxytocin EPCRS.
Ergometrine and Oxytocin Injection should be protected from light and stored at a temperature of 2° to 8°.
The strength with respect to oxytocin is stated as the number of IU (units) per mL. The label also states the equivalent number of μg of oxytocin per mL.