(Ph. Eur. 11.6 update)
Action and use
Lincosamide antibacterial.
DEFINITION
Lincomycin Injection is a sterile solution of Lincomycin Hydrochloride in Water for Injections.
The injection complies with the requirements stated under Parenteral Preparations and with the following requirements.
Content of lincomycin, C18H34N2O6S
92.5 to 107.5% of the stated amount.
CHARACTERISTICS
A colourless or almost colourless solution.
IDENTIFICATION
A. Add acetone to a volume of the injection containing the equivalent of 0.2 g of lincomycin until precipitation begins and add a further 20 mL of acetone. Filter the precipitate, wash with two 10 mL quantities of acetone, dissolve the residue in the minimum of a mixture of 4 volumes of chloroform and 1 volume of methanol, evaporate to dryness and dry at 60° at a pressure not exceeding 2 kPa for 4 hours. The infrared absorption spectrum of the dried precipitate, Appendix II A, is concordant with the reference spectrum of lincomycin hydrochloride (RS 203).
B. In the Assay, the chromatogram obtained with solution (2) shows a peak with the same retention time as the peak due to the trimethylsilyl derivative of lincomycin in the chromatogram obtained with solution (1).
TESTS
Acidity
pH 3.0 to 5.5, Appendix V L.
Lincomycin B
Examine solution (3) as described under the Assay but increase the sensitivity by 8 to 10 times while recording the peak derived from lincomycin B, which is eluted immediately before that derived from lincomycin.
LIMITS
The area of the peak derived from lincomycin B, when corrected for the sensitivity factor, is not more than 5% of the area of the peak derived from lincomycin.
Bacterial endotoxins
Carry out the test for bacterial endotoxins, Appendix XIV C. Dilute the injection if necessary with water BET to give a solution containing the equivalent of 10 mg of lincomycin per mL (solution A). The endotoxin limit concentration of solution A is 5.0 IU per mL.
ASSAY
Carry out the method for gas chromatography, Appendix III B, using the following solutions.
(1) Add 10 mL of a 0.8% w/w solution of dotriacontane (internal standard) in chloroform to 0.1 g of lincomycin hydrochloride BPCRS. Dilute to 100 mL with a 2% w/v solution of imidazole in chloroform and shake to dissolve. Place 4 mL of the resulting solution in a 15 mL ground-glass-stoppered centrifuge tube, add 1 mL of a mixture of 99 volumes of N,O-bis(trimethylsilyl)acetamide and 1 volume of trimethylchlorosilane, and swirl gently. Loosen the glass stopper and heat at 65° for 30 minutes.
(2) Prepare in the same manner as solution (1), but omit the internal standard and use the residue obtained by evaporating to dryness 1 mL of a solution prepared by diluting a volume of the injection containing the equivalent of 0.9 g of lincomycin to 10 mL with methanol, in place of the lincomycin hydrochloride BPCRS.
(3) Prepare in the same manner as solution (1), but use the residue obtained by evaporating to dryness 1 mL of a solution prepared by diluting a volume of the injection containing the equivalent of 0.9 g of lincomycin to 10 mL with methanol, in place of the lincomycin hydrochloride BPCRS.
CHROMATOGRAPHIC CONDITIONS
(a) Use a glass column (1.5 m × 3 mm) packed with acid-washed silanised diatomaceous support impregnated with 3% w/w of phenyl methyl silicone fluid (50% phenyl) (OV-17 is suitable) and maintained at 260°.
(b) Use helium as the carrier gas at a flow rate of about 45 mL per minute.
(c) Use an inlet temperature of 260° to 290°.
(d) Use a flame ionisation detector at a temperature of 260° to 290°.
(e) Inject 1 μL of each solution.
DETERMINATION OF CONTENT
Calculate the content of C18H34N2O6S in the injection using the declared content of C18H34N2O6S in lincomycin hydrochloride BPCRS.
STORAGE
Lincomycin Injection should be protected from light and stored at a temperature not exceeding 30°.
LABELLING
The strength is stated as the equivalent amount of lincomycin in a suitable dose-volume.
