Edition: BP 2025 (Ph. Eur. 11.6 update)
Action and use
Vitamin B component.
DEFINITION
Calcium Folinate Injection is a sterile solution of Calcium Folinate Hydrate. It is either supplied as a ready-to-use solution or it is prepared by dissolving Calcium Folinate for Injection in the requisite amount of Water for Injections immediately before use.
The injection complies with the requirements stated under Parenteral Preparations and, when supplied as a ready-to-use solution, with the following requirements.
Content of folinic acid, C20H23N7O7
90.0 to 110.0% of the stated amount.
IDENTIFICATION
A. To a volume containing the equivalent of 20 mg of folinic acid add 40 mL of acetone, mix, allow to stand and then centrifuge, discarding the solvent. Suspend the residue in 40 mL of acetone and centrifuge. Dry the residue in a stream of nitrogen and then at a pressure of 0.7 kPa for 2 hours. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of calcium folinate (RS 368).
B. Yields reaction B characteristic of calcium salts, Appendix VI.
TESTS
Acidity or alkalinity
pH, 6.5 to 8.5, Appendix V L.
Related substances
Carry out the method for liquid chromatography, Appendix III D, using the following solutions protected from light.
(1) Dilute with water, if necessary, a volume of the injection to produce a solution containing the equivalent of 0.1% w/v of folinic acid.
(2) Dilute 1 volume of solution (1) to 100 volumes with water.
(3) 0.1% w/v of calcium folinate BPCRS in water.
(4) Dilute 1 volume of solution (2) to 10 volumes with water.
CHROMATOGRAPHIC CONDITIONS
(a) Use a stainless steel column (25 cm × 4.6 mm) packed with end-capped octadecylsilyl silica gel for chromatography (5 μm) (Hypersil ODS is suitable).
(b) Use isocratic elution and the mobile phase described below.
(c) Use a flow rate of 1 mL per minute.
(d) Use a column temperature of 40°.
(e) Use a detection wavelength of 280 nm.
(f) Inject 20 μL of each solution.
(g) For solution (1) allow the chromatography to proceed for 2.5 times the retention time of folinate.
MOBILE PHASE
220 mL of methanol and 780 mL of a solution containing 2.0 mL of tetrabutylammonium hydroxide solution and 2.2 g of disodium hydrogen orthophosphate, previously adjusted to pH 7.5 with 10% v/v orthophosphoric acid.
When the chromatograms are recorded under the prescribed conditions, the retention times of calcium folinate and formyl folic acid are about 12 minutes and 21 minutes respectively.
SYSTEM SUITABILITY
The test is not valid unless, in the chromatogram obtained with solution (3), the resolution between the peaks corresponding to folinate and formylfolic acid is at least 2.2. If necessary, adjust the methanol content in the mobile phase.
LIMITS
In the chromatogram obtained with solution (1):
the area of any peak corresponding to formylfolic acid is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1%);
the area of any other secondary peak is not greater than the area of the principal peak in the chromatogram obtained with solution (2) (1%);
the sum of the areas of any secondary peaks, excluding the peak corresponding to formylfolic acid, is not greater than 2.5 times the area of the principal peak in the chromatogram obtained with solution (2) (2.5%).
Disregard any peak with an area less than that of the principal peak in the chromatogram obtained with solution (4) (0.1%).
ASSAY
Protect the solutions from light. Carry out the method for liquid chromatography, Appendix III D, using the following solutions.
(1) Dilute a volume of the injection with water to produce a solution containing the equivalent of 0.01% w/v of folinic acid.
(2) 0.011% w/v of calcium folinate BPCRS in water.
(3) 0.1% w/v of calcium folinate BPCRS in water.
CHROMATOGRAPHIC CONDITIONS
The chromatographic conditions described under Related substances may be used.
SYSTEM SUITABILITY
The Assay is not valid unless, in the chromatogram obtained with solution (3), the resolution between the peaks corresponding to folinate and formylfolic acid is at least 2.2. If necessary, adjust the methanol content in the mobile phase.
DETERMINATION OF CONTENT
Calculate the content of C20H23N7O7 in the injection using the declared content of C20H21CaN7O7 in calcium folinate BPCRS. Each mg of C20H21CaN7O7 is equivalent to 0.9255 mg of C20H23N7O7
STORAGE
When supplied as a ready-to-use solution, Calcium Folinate Injection should be protected from light and stored at a temperature of 2° to 8°.
LABELLING
The quantity of active ingredient is stated in terms of the equivalent amount of folinic acid.
CALCIUM FOLINATE FOR INJECTION
DEFINITION
Calcium Folinate for Injection is a sterile material consisting of Calcium Folinate Hydrate with or without excipients. It is supplied in a sealed container.
The contents of the sealed container comply with the requirements for Powders for Injections or Infusions stated under
Parenteral Preparations and with the following requirements.
Content of folinic acid, C20H23N7O7
90.0 to 110.0% of the stated amount.
IDENTIFICATION
A. The infrared absorption spectrum, Appendix II A, is concordant with the reference spectrum of calcium folinate (RS 368). If the spectra are not concordant prepare a solution containing 1% w/v of Calcium Folinate and carry out Identification Test A for the ready-to-use solution.
B. Yield reaction B characteristic of calcium salts, Appendix VI.
TESTS
Acidity or alkalinity
pH of a solution containing the equivalent of 1.0% w/v of folinic acid, 6.5 to 8.5, Appendix V L.
Related substances
Carry out the test described for the ready-to-use solution but using the following solution as solution (1). Dissolve sufficient of the mixed contents of 10 containers in water to produce a solution containing the equivalent of 0.1% w/v of folinic acid.
ASSAY
Determine the weight of the contents of 10 containers as described in the test for uniformity of weight, Appendix XII C1, Powders for Parenteral Use.
Carry out the Assay described for the ready-to-use solution but using the following solution as solution (1). Dissolve sufficient of the mixed contents of the 10 containers in water to produce a solution containing the equivalent of 0.01% w/v of folinic acid.
Calculate the content of C20H23N7O in a container of average content weight using the declared content of C20H21CaN7O7 in calcium folinate BPCRS. Each mg of C20H21CaN7O7 is equivalent to 0.9255 mg of C20H23N7O7
LABELLING
The quantity of active ingredient is stated in terms of the equivalent amount of folinic acid.
